Research progress on mechanical properties of additive manufacturing Ti-6Al-4V alloy under static and dynamic loading
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摘要: 增材制造凭借其高设计自由度和快速成形的特点,在制造复杂几何结构的航空航天和国防领域关键部件上具有巨大的优势。Ti-6Al-4V钛合金具有低密度、高比强度及抗蠕变性的特性,在经常承受冲击载荷的航天器、武器装备等关键部位上得到了广泛应用,深入了解增材制造Ti-6Al-4V钛合金在动静载荷作用下的力学性能及影响机制是提高构件使役性能的重要基础。为此,对增材制造Ti-6Al-4V钛合金的力学响应最新研究进展进行了系统的梳理和归纳。首先,简要概括了典型金属增材制造技术分类和工作原理。其次,梳理了增材制造Ti-6Al-4V钛合金的准静态拉伸性能和动态压缩性能,并与铸造和锻造Ti-6Al-4V构件的力学性能进行了比较。然后,对增材制造钛合金显微组织和力学行为的关联机制展开了讨论。最后,针对增材制造Ti-6Al-4V合金在静态载荷作用下的各向异性力学响应,总结了常用改善各向异性的后处理工艺。Abstract: With its high design freedom and rapid prototyping capabilities, additive manufacturing (AM) offers significant advantages in manufacturing critical components with complex geometries for the aerospace and defense industries. Ti-6Al-4V alloy, leveraging its exceptional combination of low density, high specific strength, and creep resistance, are extensively employed in critical structures that are frequently subjected to impact loading in aerospace and defense systems. A thorough understanding of the mechanical properties and underlying mechanisms of the additively manufactured Ti-6Al-4V alloy under static and dynamic loading is crucial for enhancing the service performance of these components. This paper systematically reviews and summarizes the latest advancements in the mechanical response of AM Ti-6Al-4V titanium alloys. Firstly, a brief overview of the classification and working principles of typical metal additive manufacturing (AM) technologies is provided. Subsequently, research efforts on the quasi-static tensile and dynamic compressive properties of additively manufactured Ti-6Al-4V titanium alloy are systematically reviewed, followed by a comparative analysis of its mechanical performance against cast and forged Ti-6Al-4V components. Furthermore, the mechanisms of correlation between the microstructure and mechanical behaviors of typical metal additive manufactured titanium alloys. Additionally, the commonly used post-processing techniques to mitigate the anisotropic mechanical response of AM Ti-6Al-4V alloy under static loading are summarizes.
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Key words:
- additive manufacturing /
- Ti-6Al-4V /
- dynamic and static loading /
- mechanical properties /
- anisotropy
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根据美国材料与试验协会(American Society for Testing and Materials, ASTM)对增材制造(additive manufacturing, AM)的定义:“与减材制造相反,依据3D模型数据,通过将材料一层一层地堆叠以制造所需部件”,增材制造也被称为3D打印、叠层制造和自由成形制造等[1]。典型金属增材制造工艺包括激光定向能量沉积(laser direct energy deposition, LDED)[2-3]、激光粉末床熔融(laser powder bed fusion, LPBF)[4-5]和电子束熔化(electron beam melting, EBM)[6-7]。增材制造具有以机加工为代表的减材制造技术所不具有的高灵活性,能够快速便捷地制造出异形零部件,可显著降低加工成本和减少材料浪费,广泛应用于加工航空航天领域复杂几何形状的关键部件,如Ti-6Al-4V钛合金航空发动机叶片[8]。此外,结构拓扑优化和增材制造技术的组合实践已成为现代制造业尤其是航空航天工业的主流设计思路,能够有效实现结构部件轻量化和高性能的设计目标[9-10]。
航空航天高性能钛合金关键承载部件往往服役于极端严苛环境中,要抵抗冲击载荷所产生的变形和破坏[11]。例如:在碎片撞击卫星、弹药打击目标、飞行器着陆或鸟类撞击飞机等情况下,钛合金部件会承受突然的冲击载荷,因此抗冲击性能是增材制造钛合金构件的一个重要评价指标[12]。增材制造钛合金在成形过程中经历快速熔化和凝固,其超过103 ℃/s的冷却速率易形成与传统制造构件不同的由柱状初生β晶粒和α晶界构成的非均质结构[13],显微组织的各向异性导致其在静态载荷作用下的力学响应呈现各向异性[14-15]。相比于静态力学响应,对增材制造钛合金动态力学响应的研究较少。
本文中,聚焦于动静载荷作用下增材制造Ti-6Al-4V的力学性能研究进展,比较典型增材制造(LPBF、LDED和EBM)、传统工艺制造(铸造、锻造)Ti-6Al-4V构件的力学性能,对增材制造Ti-6Al-4V合金显微组织与力学行为的关联机制展开讨论。针对增材制造Ti-6Al-4V在静态载荷作用下的各向异性力学响应,总结常用改善各向异性的后处理工艺。并基于增材制造Ti-6Al-4V力学性能的现有研究,对增材制造钛合金的研究方向提出展望,以期推动增材制造钛合金关键承载部件在极端环境下中的应用。
1. 典型金属增材制造工艺
采用LDED工艺制造时,以激光束为热源,原料(粉末或丝材)通过喷头或进丝装置连续输送,如图1(a)[16]所示,激光束熔化原料并沉积在基板上,基板固定,通过移动激光束成形实体构件。采用LPBF工艺制造时,需要先将粉末铺展在基板上,如图1(b)所示,高能激光束熔化粉末并沉积在基板上,在成形一层后,基板下移并重新铺展一层粉末,再次启动高能激光束熔化粉末并沉积金属。与LPBF一样,EBM也是基于粉末床的增材制造工艺[17],但EBM采用电子束作为热源且具有更高的工作功率,其工作原理如图1(c)[18]所示。
上述3种增材制造技术的成形氛围有所不同,LDED主要在开放空间并施加局部气体保护,LPBF则通常在充满惰性保护气体的封闭腔内成形,而EBM必须在真空环境中制造。LDED较简单的成形氛围使其构件易被杂质气体(如氧气、氢气等)所污染,而成形氛围要求更高的LPBF和EBM成形构件不易受到杂质气体的污染。
LDED成形时采用了比LPBF更大的光斑直径,从而获得了更高的成形效率。LPBF成形过程中的激光线能量密度比LDED的更高,其熔池内部温度梯度更大,这导致LPBF成形时熔池的冷却速率比LDED的冷却速率要高2个量级[19]。LPBF和LDED成形时基板预热至200 ℃左右[20-21],而EBM成形时基板和金属粉末都需要预热到650~700 ℃[22-23]。因此,相对于LPBF和LDED,EBM具有更低的冷却速率和平缓的温度梯度,从而降低了EBM构件的残余应力,EBM构件通常不需要进行去应力退火[13]。
表1中总结了3类典型金属增材制造工艺的制造特点,LPBF具有最高的冷却速率,EBM的冷却速率最小;在开放空间制造的LDED因其便捷性而具有最广的使役范围,而LPBF和EBM更严苛的制造要求限制了它们的应用场合;EBM构件较小的残余应力使其对热处理的需求最低。
2. 增材制造Ti-6Al-4V的显微组织和缺陷
增材制造钛合金具有复杂的热历史,搭接层金属经历多重热循环,高冷却速率产生了细小的α板条。图2[28-30]展示了LDED、LPBF和EBM成形的Ti-6Al-4V构件中形成的初生β晶粒,图3[13, 30-33]展示了上述3种增材制造 工艺和锻造、铸造成形Ti-6Al-4V 构件内部的显微结构
增材制造固有的高温度梯度使得初生β晶粒快速生长,长度甚至超过1 mm,如图2[28-30]所示。同时在初生β晶粒边界形成了具有一定厚度的α晶界,α晶界比α相脆弱,在载荷作用下细长的α晶界很容易开裂[17, 34-36]。
Ti-6Al-4V的相变主要取决于热历史和冷却速率[37]。在冷却速率足够高的情况下,当制造温度低于马氏体起始温度时,钛合金中就会产生针状α′马氏体[38]。Ti-6Al-4V合金冷却过程中针状α′马氏体形成的起始温度介于575[39]和800 ℃[40]之间,而LDED、LPBF和EBM的制造温度都低于马氏体起始温度的最大值,增材制造固有的高冷却速率会导致构件中产生大量的针状α′马氏体。在LDED制造中产生了较短的针状α′马氏体(图2(a)[28]),LPBF制造中生成了几乎穿过整个初生β晶粒的针状α′马氏体(图2(b)[29]),而EBM构件由更宽大的α板条组成(图2(c)[30]),这归因于3种成形工艺的冷却速率不同。LPBF具有比LDED更高的冷却速率,从而产生了更大的过冷度并提供了更高的驱动力,以促进针状α′马氏体生长。因此,LDED构件表现出比LPBF构件更短的针状α′马氏体。与LDED和LPBF相比,EBM较高的工作温度和多重热循环会使针状α′马氏体经历类时效处理,从而原位分解为α+β相[41-42],使得EBM构件组织表现为较宽大的α板条。
由于成形过程中较高的冷却速率,增材制造Ti-6Al-4V构件的显微组织以魏氏体结构为主,但不同制造工艺形成的魏氏体组织形态不同。LDED构件和LPBF构件中形成更致密的层状魏氏体组织(图3(a)[31]~(b)[13]),而EBM构件中形成较宽大的网篮状魏氏体组织(图3(c)[30]),文献[41-44]中都观察到了类似的微观结构。锻造构件显微组织由等轴α晶粒和β转变基体组成(图3(d)[32]),其中β转变基体内包含细小的α板条。铸造构件显微组织为层状魏氏体结构(图3(e)[33]),但其α集束尺寸远大于LDED和LPBF构件中的同类组织。
同时,增材制造过程产生的缺陷(如气孔[45]、未熔合[46]、氧化[11])和高残余应力[47-48]会显著影响构件的力学性能。图4(a)[46]、(c)[49]和(e)[50]分别展示了LDED、LPBF和EBM成形Ti-6Al-4V构件中产生的气孔,图4(b)[46]、(d)[49]和(f)[50]分别展示了LDED、LPBF和EBM成形Ti-6Al-4V构件具有粉末未熔合的缺陷。上述内部缺陷在疲劳实验[51]和拉伸实验[50]中会引发裂纹,进而影响构件的塑性,如图4(g)[51]和(h)[50]所示,前者表示粉末未熔合在LPBF Ti-6Al-4V构件中引发疲劳裂纹,后者为粉末未熔合影响EBM Ti-6Al-4V构件拉伸延展性。
3. 增材制造Ti-6Al-4V构件的力学性能
航空航天领域钛合金承载部件在实际服役过程中往往要承受动态冲击载荷[11],增材制造钛合金的实际应用不仅要考虑其在准静态载荷作用下的力学性能,还要了解其在动态冲击载荷作用下的力学响应。准静态拉伸测试(10−5~10−2 s−1)和分离式霍普金森压杆测试(split Hopkinson pressure bar, SHPB)(102~104 s−1)试验方法常用于获得钛合金在不同应变率下的力学响应。SHPB测试采用3根同材质的金属杆进行压缩实验,基于一维应力波假设获得材料的高应变率力学响应。本节中讨论增材制造Ti-6Al-4V合金的准静态拉伸性能和动态压缩性能及其影响因素。
3.1 增材制造Ti-6Al-4V的准静态拉伸性能
3.1.1 制造工艺对拉伸性能的影响
制造工艺对钛合金力学性能有显著的影响。表2中列举了不同制造工艺成形的Ti-6Al-4V构件的准静态拉伸力学性能数据[14-15, 30, 32-33, 52-53]。在增材制造Ti-6Al-4V合金中,LPBF构件表现出最大的屈服强度,这归因于LPBF构件含有较多的针状α′马氏体。针状α′马氏体具有比α板条更高的屈服强度和更差的延展性[13],它在载荷作用下更容易断裂。3种增材制造Ti-6Al-4V构件的伸长率均高于锻造Ti-6Al-4V构件。钛合金中的α/β界面会显著阻碍位错运动[54],由于具有较少的α/β界面,等轴组织通常表现出比层状组织更好的延展性[55-59]。锻造Ti-6Al-4V构件中较少的α/β界面提供了较好的延展性,同时锻造构件中极少的显微组织缺陷对材料的塑性影响很小,因此,锻造构件在准静态拉伸实验中通常表现出比增材制造构件更高的伸长率[36, 60]。
制造工艺 沉积方向 屈服强度/MPa 抗拉强度/MPa 伸长率/% 来源 LDED 水平 1050 ± 351153 ± 155.9 ± 2.5 文献[15] 973 ± 16 1073 ± 1610 ± 0.9 文献[15] 垂直 1045 ± 171140 ± 109.2 ± 0.8 文献[15] 941 ± 6 1062 ± 1111.5 ± 1.8 文献[15] LPBF 水平 1187.80 ± 35.841307.50 ± 7.46.80 ± 1.10 文献[14] 966 ± 15 1066 ± 209.8 ± 3.3 文献[52] 垂直 1036.70 ± 133.71309.50 ± 8.28.72 ± 2.77 文献[14] 937 ± 9 1052 ± 119.6 ± 0.9 文献[52] EBM 水平 769 ± 12 867 ± 11 12.0 ± 1.5 文献[30] 846 ± 7 976 ± 11 15.0 ± 2.0 文献[53] 垂直 710 ± 1 814 ± 2.5 15 ± 0.5 文献[30] 845 ± 9 972 ± 14 14.2 ± 1.5 文献[53] 锻造 960 ± 10 1006 ± 1018.37 ± 0.88 文献[32] 铸造 837 900 6.8 文献[33] 制造工艺对合金中的显微组织有很大的影响,这归因于不同制造工艺的热历史不同。EBM Ti-6Al-4V构件比LDED和LPBF Ti-6Al-4V构件具有更好的韧性,这是由位错分布模式决定的[55]。在网篮状魏氏体组织中,位错运动被不同取向的α晶粒阻碍,位错堆积在α/β界面中(图5(a)[55]);而层状魏氏体组织中拥有较大的α集束,位错可以在α集束内滑移并在边界处堆积造成应力集中(图5(b)[55])。相比于层状魏氏体组织,网篮状魏氏体组织中的位错分布更均匀,局部应力集中程度更低,协调变形能力更好。铸造构件中层状魏氏体组织的α集束尺寸大于LDED和LPBF构件中的同类组织,更宽大的α集束可能会在边界处积累更多的位错,位错堆积形成的应力集中可能会诱发空洞形核和合并,最终形成裂纹并降低塑性,导致铸造构件表现出较差的延展性。
残余应力同样会显著影响构件的延展性[61-62]。残余应力与成形过程的温度梯度密切相关,增材制造钛合金固有的高温度梯度会给构件内部带来残余应力[47-48]。LDED的冷却速率介于LPBF和EBM之间。具有最高冷却速率的LPBF会使构件在制造时产生极大的残余应力[63-64],LPBF构件中较高的残余应力会导致构件形成微裂纹和翘曲,显著影响材料的延展性。EBM较低的冷却速率产生的较平缓的温度梯度显著降低了构件中的残余应力[65],EBM构件中几乎可以忽略不计的残余应力对材料的延展性影响甚微。
晶粒尺寸对屈服强度也有重要影响。依据Hall-Petch公式[66-67],即σy=σ0+kd-1/2,材料的屈服强度与晶粒尺寸成反比。其中,σy为材料的屈服极限,σ0为移动单个位错时产生的晶格摩擦阻力,k为与材料的种类性质有关的常数,d为平均晶粒尺寸。注意到LPBF构件和LDED构件中α/α′板条的宽度明显低于铸造构件和EBM构件中同类组织的宽度。LDED和LPBF构件中针状α′马氏体板条的宽度为0.2~1.0 μm(图3(a)[31]~(b)[13]),EBM构件中α板条的宽度为2~6 μm(图3(c)[30]),锻造构件中等轴α晶粒的尺寸为15~25 μm(图3(d)[32]),而铸造构件中α板条的宽度为2~7 μm(图3(e)[33])。LDED、LPBF构件中含有大量的针状α′马氏体,针状α′马氏体中包含高密度的位错[66],LDED、LPBF构件可以通过位错强化产生更大的硬化。因此,拥有较小晶粒尺寸和额外位错强化的LDED、LPBF构件表现出较高的屈服强度。
钛合金的力学性能还与有效滑移长度有关,屈服应力与有效滑移长度成反比[55, 68]。在准静态拉伸实验中,材料通常以位错滑移产生变形[69]。在层状魏氏体中,有效滑移长度为α集束的尺寸;而在网篮状魏氏体中,有效滑移长度为不同取向α板条的长度[55]。在显微组织由等轴α晶粒和β转变基体构成的锻造构件中,有效滑移长度即为等轴α晶粒尺寸。图2~3展示了LDED、LPBF、EBM、锻造和铸造成形的Ti-6Al-4V构件的显微组织,其中LDED、LPBF和EBM构件中有效滑移长度分别为25~40、30~50和15~30 μm,锻造构件中有效滑移长度为15~25 μm,铸造构件中有效滑移长度为30~50 μm。有效滑移长度与晶粒尺寸有着内在的联系,α板条宽度的增大同时会导致α集束尺寸的增大,从而导致有效滑移长度的增大,屈服应力与有效滑移长度成反比,更大的有效滑移长度会产生更低的屈服应力。相对于LDED、LPBF和EBM构件,锻造构件拥有较小的有效滑移长度,且锻造构件中β转变基体包含细小的α板条,这些α板条会阻碍位错运动,从而产生额外强化效应[70],因而锻造构件表现出较高的屈服强度。而拥有最宽的α板条和最大有效滑移长度的铸造构件会表现出最低的屈服强度。
3.1.2 沉积方向对拉伸性能的影响
不同沉积方向增材制造钛合金的力学性能有显著的差异,增材制造Ti-6Al-4V构件呈现拉伸各向异性。以HD表示沉积方向为水平方向(horizontal direction),即HD成形构件选取的准静态拉伸试件和动态压缩试件的长轴垂直沉积方向,如图6(a)所示;以VD表示沉积方向为垂直方向(vertical direction),VD成形构件中选取的准静态拉伸试件和动态压缩试件的长轴平行沉积方向,如图6(b)所示。从表2[14-15, 30, 32-33, 52-53]可以看出,在增材制造Ti-6Al-4V构件的准静态拉伸测试中,HD成形构件通常表现出更高的屈服强度,而VD成形构件具有更高的伸长率。
拉伸性能的各向异性与显微组织排列结构有很大的联系。增材制造钛合金中的β晶粒沿沉积方向生长,在β晶粒间有连续的α晶界。HD成形构件中的β晶粒长轴垂直于拉伸载荷,这导致沿初生β晶粒间的α晶界容易产生裂纹,较长的β晶界为裂缝扩张提供了优先路径[36],构件产生晶间断裂(图7(a)[36])。图7(b)[36]展示了VD成形构件的断裂形貌,构件中β晶粒长轴平行于拉伸载荷,当α晶界处产生裂纹后,裂纹的传播路径在穿过不同β晶粒时会产生偏移并消耗更多的能量,这就意味着裂纹的扩张更难,VD成形构件容易产生沿晶断裂,从而构件表现出更强的韧性。
沉积方向同样影响构件的散热,沿HD沉积的构件与基板的接触面积大于VD沉积构件,HD成形构件产生了更大的温度梯度。相应地,成形过程中产生的热量在HD成形构件中比在VD成形构件中更有效地通过基板传导,即HD成形构件的冷却速率高于VD成形构件[71],这导致HD成形构件产生了更多的细针状α′马氏体。此外,在成形过程中,构件的搭接层会发生重熔,这些重熔区经历多次热循环。成形过程中的这种重熔行为会促进Ti-6Al-4V合金中针状α′马氏体原位分解为片层状α+β相[72-73]。相比于HD成形构件,VD成形构件在沉积方向具有更大的尺寸,VD成形构件不仅冷却更慢,并且经历更频繁的重熔,因此它会保留更少的针状α′马氏体。针状α′马氏体的强度高但塑性差,导致VD成形构件具有较强的塑性和较低的屈服强度。
增材制造钛合金独特的成形过程产生了
<100> β//沉积方向的纤维织构[30, 74-75],由于钛合金的α和β相间存在{0001}α//{110}β和<11-20> α//<111> β的伯格斯位向关系(Burgers orientation relationship, BOR)[66],这使得成形态钛合金表现出<11-20> α//沉积方向的织构[30, 74-77]。钛合金的基底滑移系({0001}α<11-20> α)的临界分解剪切应力(critical resolved shear stress, CRSS)与柱面滑移系({10-11}α<11-20> α)相当,但均远低于锥体滑移系({10-11}α<11-20> α或{10-11}α<11-23> α)[78-79]。在低应变率加载时,锥体滑移系难以被激活[80-81]。VD成形构件中的<11-20> α织构在准静态拉伸载荷作用下表先出较高的基底滑移和柱面滑移施密特因子(Schmid factor, SF),而HD成形构件具有相对均匀的SF取向分布[30],HD成形构件中的基底滑移和柱面滑移系统在拉伸时更难以激活,较低的滑移倾向性导致HD成形构件表现出比VD成形构件更高的屈服强度。3.1.3 后处理工艺对增材制造Ti-6Al-4V钛合金各向异性的影响
增材制造钛合金在静态载荷下表现出的力学性能各向异性限制了其在航天器、武器装备等领域的应用,现有研究集中于采取热处理工艺改善增材制造钛合金的各向异性[77, 82-83]。Ti-6Al-4V合金的常用热处理工艺可分为去应力退火[84]、固溶热处理[85]、固溶时效热处理[86]和β退火[87]。这些热处理工艺之间的区别主要为退火温度不同:去应力退火的退火温度低于再结晶温度(750 ℃);固溶热处理的退火温度居于750 ℃和β转变温度(995 ℃)之间;时效处理在固溶热处理后进行,其退火温度为450~550 ℃;β退火的退火温度高于995 ℃。
图8[82]为LPBF Ti-6Al-4V在经过不同后处理工艺(保温时间2.5 h,炉冷)后水平和垂直沉积块状材料的显微组织,较低放大倍数的图像为光学显微镜(optical microscope, OM)图像,其中较暗的区域为β相,较亮的区域为α相;放大倍数较高的是扫描电镜(scanning electron microscope, SEM)图像,其中较亮的区域为β相,较暗的区域为α相。图8(a)~(b)为成形态试样,表现为包含大量针状α′马氏体的柱状初生β晶粒结构;图8(c)~(d)展示的为固溶温度为750 ℃的热处理态组织,成形态中的针状α′马氏体分解为由α+β相构成的层状魏氏体组织;图8(e)~(h)展示的分别为固溶温度为850和920 ℃的热处理态组织,它们具有相似的层状魏氏体组织;图8(i)~(j)展示的为退火温度为
1050 ℃的热处理态组织,由于退火温度超过了995 ℃,图8(i)所示的柱状初生β晶粒发生等轴化,材料表现为均匀的网篮状魏氏体组织,2个沉积方向具有类似的组织。随着退火温度的升高,柱状初生β晶粒愈加等轴化,2个沉积方向的显微组织差异近乎完全消除。值得注意的是,常用的后处理工艺(热处理工艺或热等静压(hot isostatic pressing, HIP)工艺)均无法完全消除增材制造钛合金在静态载荷下的力学性能各向异性[77, 82, 88-93]。去应力退火时较低的退火温度难以完全分解针状α′马氏体[94-95],热处理后保留的大量针状α′马氏体会严重削弱构件的塑性。低退火温度使得成形态构件中的柱状初生β晶粒得到最大程度的保留,不同沉积方向的微观结构各向异性导致力学性能的各向异性。
为表征增材制造钛合金在静态载荷下力学性能的各向异性程度,采用屈服强度差比ry、抗拉强度差比rt和伸长率差比R量化沉积方向对力学性能的影响[82],其计算公式如下:
ry=|σy,h−σy,vσy,h|,rt=|σt,h−σt,vσt,h|,R=|εh−εvεh| (1) 式中:σy、σt和ε分别为屈服强度、抗拉强度和伸长率,下标h和v表示水平和垂直沉积方向。
表3展示了典型增材制造Ti-6Al-4V的拉伸各向异性[1, 82-83, 88, 92]。表中展示数据均来自于750 ℃以上退火后的材料,随着退火温度的升高,热处理工艺由固溶热处理转换为β退火,增材制造Ti-6Al-4V的各向异性显著减弱。这归因于构件中的柱状初生β晶粒和α晶界在热处理时发生了较大的变化,柱状初生β晶粒使得不同沉积方向的显微组织表现出各向异性,显微组织的各向异性导致宏观力学行为的各向异性[82, 96]。热处理时退火温度的提高促进柱状初生β晶粒等轴化,并消除显微组织的各向异性[82, 97]。经过固溶处理或β退火,增材制造钛合金中的针状α′马氏体完全分解为α+β相[96],高退火温度提供了α板条充分生长的驱动力。图8(i)和(j)为2个沉积方向β退火后的显微组织,高于995 ℃的退火温度使得柱状初生β晶粒近乎完全等轴化,2个沉积方向材料均表现为近似的网篮状魏氏体组织,虽然不同沉积方向的显微组织近乎一致,但其静态载荷下的力学性能仍存在微弱的各向异性。可以看出,热处理工艺能够改善增材制造Ti-6Al-4V的各向异性。但在995 ℃以上退火后,显微组织的各向同性难以解释力学性能上微弱的各向异性。
制造工艺 后处理工艺 后处理工艺制度 ry/% rt/% R/% 来源 LDED 成形态 2.7 3.8 32.62 文献[1] 固溶热处理 980 ℃下保温1 h后炉冷 4.07 2.13 21.21 LPBF 成形态 17.0 18.3 18.2 文献[82] 固溶热处理 750 ℃下保温2.5 h后炉冷 2.6 3.6 8 850 ℃下保温2.5 h后炉冷 4.3 3.4 7.5 920 ℃下保温2.5 h后炉冷 4.9 7.6 1.1 β退火 1050 ℃下保温2.5 h后炉冷1.8 0.2 2.2 成形态 11.5 9.5 19.23 文献[88] β退火 1100 ℃下保温2 h后炉冷0.8 0.5 4.7 成形态 9 14.5 42.7 文献[83] 固溶时效热处理 910 ℃下保温4 h后水淬,再于750℃下保温2 h后空淬, 11.2 4.3 30.4 成形态 28.5 45.2 文献[92] 固溶热处理 850 ℃下保温0.5 h后空冷 11.9 8.2 900 ℃下保温0.5 h后空冷 16.2 7.2 950 ℃下保温0.5 h后空冷 0.7 3.4 固溶时效热处理 850 ℃下保温0.5 h后空冷,再于600℃下保温2 h后空冷 8.7 4.1 900 ℃下保温0.5 h后空冷,再于600℃下保温2 h后空冷 21.4 5.1 950 ℃下保温0.5 h后空冷,再于600℃下保温2 h后空冷 1.5 7.5 现有研究[77, 89]表明,增材制造钛合金内
<11-20> α//沉积方向的织构同样会产生力学性能各向异性,该织构由成形过程产生的<100> β//沉积方向的纤维织构经伯格斯位向关系生成,热处理时较短的保温时间(1~3 h)难以完全消除<11-20> α//沉积方向的织构对力学性能的影响。因此,β退火后,即使不同沉积方向具有近乎一致的显微组织,<11-20> α//沉积方向的织构仍会导致力学性能产生微弱的各向异性。3.2 增材制造Ti-6Al-4V的动态压缩性能
钛合金在动态载荷下的应力-应变行为受应变硬化、应变率硬化和热软化等机制共同作用。应变硬化表现为加载过程中应力随着应变增加而增加。而在高应变率下,短暂的加载时间导致只有一部分冲击生成的热量通过对流、传导和辐射散布到周围环境中,剩余的热量提高了材料的温度。材料的剧烈升温将降低流动应力,这种影响被称为热软化[98]。高应变率使材料的晶粒产生扭曲、旋转和破碎[99],位错堆积更严重,并表现出比低应变率加载时更高的流动应力,这种影响被称为应变率硬化[100]。
3.2.1 增材制造Ti-6Al-4V的应力-应变行为
在增材制造Ti-6Al-4V[46, 101-107]的动态压缩性能方面已有不少的研究。图9[46, 107, 108-110]展示了3种增材制造技术(LDED、LPBF和EBM)和2种传统工艺(锻造和铸造)成形的Ti-6Al-4V构件动态压缩的力学行为。虽然测试应变率范围不一致,但Ti-6Al-4V构件在动态压缩下的屈服强度和极限应变似乎与成形工艺有关。在应变率相近的实验条件下,LPBF构件表现出最高的屈服强度和仅次于锻造构件的塑性(图9(b)[107]和(d)[109]),LDED构件具有仅次于LPBF构件的屈服强度和塑性(图9(a)[46]),EBM构件在加载时强烈的应变硬化产生了仅比LPBF构件低的极限抗压强度(图9(c)[108]),铸造构件则表现为最低的屈服强度和极限抗压强度(图9(e)[110])。当LDED构件测试应变率提高到
7000 s−1时,试件的延展性反而下降(图9(b)[107])。这归因于热软化导致绝热剪切带(adiabatic shear band, ASB)的形成[111],ASB的发展会导致局部剪切塑性失稳[112],降低了动态压缩时的延展性。随着应变率的提高,ASB发展更迅速,材料表现出更低的塑性。图10(a)展示了增材制造Ti-6Al-4V合金在动态压缩时的应力-应变行为,而图10(b)则展示了与图10(a)相对应的应变硬化率-应变行为。增材制造Ti-6Al-4V合金动态压缩变形行为可以分为4段,由于高应变率下更大冲击引起的瞬时应变硬化[113],材料更早达到屈服阶段,阶段1表现出更快的屈服和逐渐降低的应变硬化率,更高应变率冲击会导致形成更小的应变ε1,同时由于初始加载时弹性波的弥散,阶段1难以表现出完全的线弹性。在塑性变形的开始阶段,塑性功产生的热量不足以使材料发生显著软化,应变硬化起着更重要的作用,因此阶段2的流变行为是略微上升的“平台段”,对应于图10(b)中ε1-ε2阶段表现出的平缓下降的应变硬化率。在阶段3中,热软化产生的影响逐步超过应变硬化的影响,流变曲线则表现为略微下降的“平台段”,对应于ε2-ε3阶段负值的应变硬化率。值得注意的是,阶段2和阶段3的“平台段”是宏观视角的结果,细致观察应力-应变行为表现为波浪起伏的曲线,这是应变硬化与热软化竞争所导致的。阶段4表现为显著的应力下降,表现为应变硬化率曲线斜率急剧减小,这是由热软化和快速卸载所导致的。一方面,剧烈的热软化使得流动应力显著下降;另一方面,SHPB实验无法保持恒定的应变率加载[17],材料将在实验后段产生快速卸载。剧烈的卸载过程会导致流动应力下降。
应变率的提高会使阶段2的间距缩短和阶段3的间距增加,这归因于更高应变率加载产生的更剧烈的热软化。同时注意到随着应变率的升高,ε4显著增大。
3.2.2 增材制造Ti-6Al-4V动态压缩力学性能的影响因素
3.2.2.1 沉积方向对动态压缩力学性能的影响
在增材制造钛合金沉积方向对动态压缩行为的影响方面,现有研究结论并不一致。部分研究结果表明沉积方向对动态压缩下的流动应力影响微不足道[46, 103, 112],动态压缩下流动应力表现为各向同性,其原因是由于高应变率下初生β晶粒对塑性变形的影响很小,材料变形行为主要取决于β晶粒内的α板条特性[46]。但在文献[17]中发现增材制造Ti-6Al-4V在动态压缩下具有明显的各向异性,这归因于VD成形构件经历了更多的重熔产生了更精细的微观结构,因而表现出更大的流动应力。Waymel等[103]认为高应变率测试产生的噪声可能掩盖了取向的依赖性。然而,上述研究结论是基于不同的增材制造工艺,如文献[17]采用EBM成形,而文献[46, 103, 112],则采用LDED或LPBF成形,增材制造工艺的差异同样会对动态压缩力学性能产生影响。目前,对这一方面的研究并不充分,尚不能完全揭示沉积方向和增材制造钛合金动态压缩力学性能之间的联系。
3.2.2.2 应变率对动态压缩行为的影响
高速冲击载荷作用下,晶粒易产生扭曲、旋转和破碎,晶粒尺寸显著降低[17]。应变率越高,位错堆积越严重,位错密度也随之提高。依据Hall-Petch公式和位错强化理论,材料将表现出更高的流动应力,常采用应变率敏感系数m[114]来量化应变率对材料应力-应变行为的影响:
m=∂lnσ∂ln˙ε=ln(σ2/σ2σ1σ1)ln(˙ε2/˙ε2˙ε1˙ε1) (2) 式中:
σ2 和σ1 分别为在应变率˙ε2 和˙ε1 下给定应变处的应力值。基于应变率敏感系数,可将材料分为3类:应变率不敏感材料(m=0),正应变率敏感材料(m>0)和负应变率敏感材料(m<0)。在动态压缩条件下,各增材制造工艺成形的钛合金都表现出显著的正应变率敏感性,即高应变率下表现出更高的流动应力[46, 101-107];在锻造钛合金中同样可以观察到正应变率敏感性[101]。表4[17, 46, 101, 103]给出了不同制造工艺成形的Ti-6Al-4V构件的应变率敏感系数的测试结果,可以看出,EBM构件具有比LDED构件、LPBF构件和锻造构件更高的应变率敏感性,LPBF构件和EBM构件在应变率敏感性上呈现微弱的各向异性。值得注意的是,表4中EBM构件的测试应变率范围较低(150~
1100 s−1),其余制造工艺成形构件的应变率测试范围均超过1100 s−1。由于这些研究的动态压缩应变率范围存在差异,因此无法判断EBM Ti-6Al-4V表现出的最高的正应变率敏感性是该工艺固有特性还是测试应变率范围不同所引起。制造工艺 热处理 应变率/s−1 屈服强度/MPa m 来源 LDED 1000 (HD)1247 0.12 文献[46] 5000 (HD)1479 LDED 920 C°保温2 h+540 C°保温4 h 1000 (VD)1054 0.05 文献[101] 3000 (VD)1130 LPBF 1340 (HD)1770 0.08 文献[103] 6370 (HD)2020 380(VD) 1720 0.05 5540 (VD)2060 EBM 150(HD) 705 ± 17 0.24 文献[17] 1100 (HD)1127 ± 22150(VD) 805 ± 13 0.21 1100 (VD)1257 ± 25锻造 1000 1318 0.11 文献[46] 5000 1602 在应变率相近的实验条件下,LDED构件和锻造构件表现出近乎一致的应变率敏感性,且它们都拥有比LPBF构件更高的应变率敏感性,这可能是制造工艺的固有特性导致的。应变率敏感性与材料的应变硬化有关,应变硬化的下降会产生较低的应变率敏感系数。LPBF构件中较多的针状α′马氏体可能在高应变率加载时更早产生损伤,导致材料表现出较差的应变硬化,低的应变硬化表现出较低的应变率敏感系数。此外,热处理后的LDED构件表现出较低的应变率敏感性,但文献[46, 101]采用的制造工艺参数不一样,因此难以判断热处理对增材制造钛合金的应变率敏感性的影响。
在应变率相近的实验条件下,LDED Ti-6Al-4V表现出最好的塑性,而LPBF Ti-6Al-4V具有较差的塑性(图11[17,46,101]),其原因在于LPBF Ti-6Al-4V中较多的针状α′马氏体降低了构件的延展性。由于应变率范围不同,因此无法比较更高应变率下(>
1100 s−1)LDED、LPBF和EBM成形的Ti-6Al-4V构件之间的延展性差异。在增材制造Ti-6Al-4V构件动态压缩实验中,加载应变率的提高会显著提升极限应变,显示出应变率增塑效应。从材料变形角度考虑,通常材料变形需要5个独立滑移系统,而基底和柱面滑移只有4个独立滑移系统[102]。高应变率冲击产生的更大作用力会激活更多的锥体滑移系以适应变形要求[115]。当锥体滑移处于硬取向时,材料会产生孪晶满足变形要求[116]。在钛合金动态压缩中通常会产生{10-12}α拉伸孪晶[76, 117],{10-12}α孪晶在动态压缩时的CRSS为346~361 MPa[76],而钛合金基底滑移系统、柱面滑移系统和锥体滑移系统的CRSS值分别为444、380和631MPa[118]。相比于锥体滑移系统,{10-12}α拉伸孪晶的CRSS较小,因而钛合金在动态压缩时容易产生{10-12}α孪晶,更高应变率的加载会产生更多的孪晶[76, 118]。在孪晶诱导塑性效应[119]的作用下,材料表现出更大的延展性。因此,在高应变率下,材料会激活更多锥体滑移系或产生更多孪晶从而提高塑性。
4. 总结和展望
增材制造Ti-6Al-4V钛合金准静态拉伸时呈现出显著各向异性的作用机理已有较为充分的研究,但在增材制造钛合金的动态压缩性能方面,现有研究尚无法完整揭示出增材制造钛合金的冲击变形机制,已有的实验方法(如SHPB、轻气炮平板撞击层裂实验等)仅能得到材料的宏观力学行为,而不能揭示材料塑性流动的具体过程。纵观增材制造Ti-6Al-4V钛合金准静态拉伸和动态压缩力学性能研究进程,在以下方面仍需深入研究:
(1)增材制造钛合金在极端环境载荷下的力学行为研究不全面。航空航天使用的增材制造钛合金部件多服役于各种极端环境中,如高应变率载荷、低/高温和超高压等。现有增材制造钛合金力学行为研究主要侧重于极端环境载荷情况的单一方面(高温或高应变率),对于极端温度梯度、高应变率和多场耦合情况下的力学行为有待深入研究。此外,增材制造钛合金实际服役时会经历多重载荷循环,对增材制造钛合金在高温高应变率耦合作用下的疲劳行为研究需进一步拓展。
(2)增材制造钛合金沉积方向与动态力学响应的关系有待进一步研究。现有研究结果表明增材制造钛合金准静态拉伸性能具有显著的各向异性,但不同沉积方向对动态载荷作用下力学性能的影响尚未得到充分研究。为充分了解增材制造钛合金沉积方向与动态力学响应的关系,还需要研究包括制造工艺、动态载荷加载和后处理等条件下沉积方向对其动态力学响应的影响机制。
(3)增材制造钛合金微观组织与动态响应关联机制有待进一步研究。在增材制造钛合金显微组织与准静态性能的关系方面已有大量研究,而对动态响应的研究主要集中在增材制造钛合金的宏观力学行为上,对其显微组织与动态性能的关联机制鲜有关注。研究增材制造钛合金显微组织演变与应变率的关联机制将有助于揭示增材制造钛合金在动态载荷作用下的变形失效机制。
(4)开发适用于增材制造钛合金的本构模型仍是一个巨大的挑战。增材制造钛合金在动态压缩时受到应变硬化、应变率硬化和热软化的共同作用,更高应变率的加载显著加剧热软化。现有研究集中于拟合J-C本构方程以适用于增材制造钛合金,但将应变硬化、应变率硬化和热软化分别解耦的J-C本构方程无法准确反映增材制造钛合金实际变形机理。考虑到本构模型在数值模拟领域的广泛应用,开发将应变硬化、应变率硬化和热软化耦合的增材制造钛合金本构模型具有重要意义。
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表 2 由不同制造工艺成形的Ti-6Al-4V构件的准静态拉伸力学性能[14-15, 30, 32-33, 52-53]
Table 2. Quasi-static tensile mechanical properties of Ti-6Al-4V components prepared by different manufacturing processes[14-15, 30, 32-33, 52-53]
制造工艺 沉积方向 屈服强度/MPa 抗拉强度/MPa 伸长率/% 来源 LDED 水平 1050 ± 351153 ± 155.9 ± 2.5 文献[15] 973 ± 16 1073 ± 1610 ± 0.9 文献[15] 垂直 1045 ± 171140 ± 109.2 ± 0.8 文献[15] 941 ± 6 1062 ± 1111.5 ± 1.8 文献[15] LPBF 水平 1187.80 ± 35.841307.50 ± 7.46.80 ± 1.10 文献[14] 966 ± 15 1066 ± 209.8 ± 3.3 文献[52] 垂直 1036.70 ± 133.71309.50 ± 8.28.72 ± 2.77 文献[14] 937 ± 9 1052 ± 119.6 ± 0.9 文献[52] EBM 水平 769 ± 12 867 ± 11 12.0 ± 1.5 文献[30] 846 ± 7 976 ± 11 15.0 ± 2.0 文献[53] 垂直 710 ± 1 814 ± 2.5 15 ± 0.5 文献[30] 845 ± 9 972 ± 14 14.2 ± 1.5 文献[53] 锻造 960 ± 10 1006 ± 1018.37 ± 0.88 文献[32] 铸造 837 900 6.8 文献[33] 表 3 典型增材制造工艺成形的Ti-6Al-4V构件的拉伸各向异性[1, 82-83, 88, 92]
Table 3. Anisotropic tensile behaviors of additively manufactured Ti-6Al-4V specimens[1, 82-83, 88, 92]
制造工艺 后处理工艺 后处理工艺制度 ry/% rt/% R/% 来源 LDED 成形态 2.7 3.8 32.62 文献[1] 固溶热处理 980 ℃下保温1 h后炉冷 4.07 2.13 21.21 LPBF 成形态 17.0 18.3 18.2 文献[82] 固溶热处理 750 ℃下保温2.5 h后炉冷 2.6 3.6 8 850 ℃下保温2.5 h后炉冷 4.3 3.4 7.5 920 ℃下保温2.5 h后炉冷 4.9 7.6 1.1 β退火 1050 ℃下保温2.5 h后炉冷1.8 0.2 2.2 成形态 11.5 9.5 19.23 文献[88] β退火 1100 ℃下保温2 h后炉冷0.8 0.5 4.7 成形态 9 14.5 42.7 文献[83] 固溶时效热处理 910 ℃下保温4 h后水淬,再于750℃下保温2 h后空淬, 11.2 4.3 30.4 成形态 28.5 45.2 文献[92] 固溶热处理 850 ℃下保温0.5 h后空冷 11.9 8.2 900 ℃下保温0.5 h后空冷 16.2 7.2 950 ℃下保温0.5 h后空冷 0.7 3.4 固溶时效热处理 850 ℃下保温0.5 h后空冷,再于600℃下保温2 h后空冷 8.7 4.1 900 ℃下保温0.5 h后空冷,再于600℃下保温2 h后空冷 21.4 5.1 950 ℃下保温0.5 h后空冷,再于600℃下保温2 h后空冷 1.5 7.5 表 4 典型制造工艺成形的Ti-6Al-4V构件的应变率敏感性[17, 46, 101, 103]
Table 4. Strain rate sensitivity of Ti-6Al-4V components formed by typical manufacturing process[17, 46, 101, 103]
制造工艺 热处理 应变率/s−1 屈服强度/MPa m 来源 LDED 1000 (HD)1247 0.12 文献[46] 5000 (HD)1479 LDED 920 C°保温2 h+540 C°保温4 h 1000 (VD)1054 0.05 文献[101] 3000 (VD)1130 LPBF 1340 (HD)1770 0.08 文献[103] 6370 (HD)2020 380(VD) 1720 0.05 5540 (VD)2060 EBM 150(HD) 705 ± 17 0.24 文献[17] 1100 (HD)1127 ± 22150(VD) 805 ± 13 0.21 1100 (VD)1257 ± 25锻造 1000 1318 0.11 文献[46] 5000 1602 -
[1] ALCISTO J, ENRIQUEZ A, GARCIA H, et al. Tensile properties and microstructures of laser-formed Ti-6Al-4V [J]. Journal of Materials Engineering and Performance, 2011, 20(2): 203–212. DOI: 10.1007/s11665-010-9670-9. [2] 周平, 郭伟国, 李鹏辉, 等. 激光立体成形TC4钛合金的力学特性与破坏机理 [J]. 材料科学与工程学报, 2019, 37(1): 56–63. DOI: 10.14136/j.cnki.issn1673-2812.2019.01.011.ZHOU P, GUO W G, LI P H, et al. Mechanical properties and failure mechanism of laser solid formed TC4 Titanium Alloy [J]. Journal of Materials Science and Engineering, 2019, 37(1): 56–63. DOI: 10.14136/j.cnki.issn1673-2812.2019.01.011. [3] 陈志茹, 计霞, 楚瑞坤, 等. 热处理工艺对激光熔化沉积TC4钛合金组织性能的影响 [J]. 金属热处理, 2018, 43(11): 144–149. DOI: 10.13251/j.issn.0254-6051.2018.11.030.CHEN Z R, JI X, CHU R K, et al. Effect of heat treatment on microstructure and properties of TC4 titanium alloy by laser melting deposition [J]. Heat Treatment of Metals, 2018, 43(11): 144–149. DOI: 10.13251/j.issn.0254-6051.2018.11.030. [4] 谢文强, 王洁琪, 庄沛林, 等. 构建方向对SLM钛合金卡环的显微结构及性能影响 [J]. 口腔疾病防治, 2019, 27(1): 17–22. DOI: 10.12016/j.issn.2096-1456.2019.01.004.XIE W Q, WANG J Q, ZHUANG P L, et al. Effect of construction orientation on the microstructure and properties of SLM Ti alloy clasps [J]. Journal of Dental Prevention and Treatment, 2019, 27(1): 17–22. DOI: 10.12016/j.issn.2096-1456.2019.01.004. [5] 辛如意, 兰亮, 何博. 选区激光熔化增材制造钛合金的疲劳性能研究进展 [J]. 材料科学与工程学报, 2022, 40(4): 706–716. DOI: 10.14136/j.cnki.issn1673-2812.2022.04.025.XIN R Y, LAN L, HE B. Research progress on fatigue properties of titanium alloy fabricated by selective laser melting [J]. Journal of Materials Science and Engineering, 2022, 40(4): 706–716. DOI: 10.14136/j.cnki.issn1673-2812.2022.04.025. [6] 张国栋, 张鹏, 高健时, 等. 电子束熔丝增材制造TC11钛合金组织及力学性能 [J]. 机械工程学报, 2023, 59(4): 105–112. DOI: 10.3901/JME.2023.04.105.ZHANG G D, ZHANG P, GAO J S, et al. Microstructure and mechanical properties of TC11 titanium alloy fabricated by wire-feed electron beam additive manufacturing [J]. Journal of Mechanical Engineering, 2023, 59(4): 105–112. DOI: 10.3901/JME.2023.04.105. [7] 王宁宁, 韩冬, 吴军, 等. 电子束熔丝增材制造TC11钛合金显微组织及力学性能研究 [J]. 航天制造技术, 2019(6): 36–39. DOI: 10.3969/j.issn.1674-5108.2019.06.009.WANG N N, HAN D, WU J, et al. Microstructure and mechanical properties of TC11 titanium alloy electron beam fuse additive manufacturing [J]. Aerospace Manufacturing Technology, 2019(6): 36–39. DOI: 10.3969/j.issn.1674-5108.2019.06.009. [8] 王华明. 高性能大型金属构件激光增材制造: 若干材料基础问题 [J]. 航空学报, 2014, 35(10): 2690–2698. DOI: 10.7527/S1000-6893.2014.0174.WANG H M. Materialsʼ fundamental issues of laser additive manufacturing for high-performance large metallic components [J]. Acta Aeronautica et Astronautica Sinica, 2014, 35(10): 2690–2698. DOI: 10.7527/S1000-6893.2014.0174. [9] ZHU J H, ZHOU H, WANG C, et al. A review of topology optimization for additive manufacturing: status and challenges [J]. Chinese Journal of Aeronautics, 2021, 34(1): 91–110. DOI: 10.1016/j.cja.2020.09.020. [10] XU Y L, ZHANG D Y, ZHOU Y, et al. Study on topology optimization design, manufacturability, and performance evaluation of Ti-6Al-4V porous structures fabricated by selective laser melting (SLM) [J]. Materials, 2017, 10(9): 1048. DOI: 10.3390/ma10091048. [11] 刘洋, 徐怀忠, 汪小锋, 等. 冲击载荷下增材制造金属材料的动态响应及微观结构演化研究进展 [J]. 高压物理学报, 2021, 35(4): 040102. DOI: 10.11858/gywlxb.20210760.LIU Y, XU H Z, WANG X F, et al. Progress in dynamic responses and microstructure evolution of the additive manufactured alloys under impact load [J]. Chinese Journal of High Pressure Physics, 2021, 35(4): 040102. DOI: 10.11858/gywlxb.20210760. [12] LIU Y, XU H Z, ZHU L, et al. Investigation into the microstructure and dynamic compressive properties of selective laser melted Ti-6Al-4V alloy with different heating treatments [J]. Materials Science and Engineering: A, 2021, 805: 140561. DOI: 10.1016/j.msea.2020.140561. [13] LIU S Y, SHIN Y C. Additive manufacturing of Ti6Al4V alloy: a review [J]. Materials & Design, 2019, 164: 107552. DOI: 10.1016/j.matdes.2018.107552. [14] TAO P, ZHONG J W, LI H X, et al. Microstructure, mechanical properties, and constitutive models for Ti–6Al–4V Alloy fabricated by selective laser melting (SLM) [J]. Metals, 2019, 9(4): 447. DOI: 10.3390/met9040447. [15] AMSTERDAM E, KOOL G A. High cycle fatigue of laser beam deposited Ti-6Al-4V and inconel 718 [C]//Proceedings of the 25th Symposium of the International Committee on Aeronautical Fatigue, ICAF 2009, Bridging the Gap between Theory and Operational Practice. Rotterdam: Springer, 2009: 1261–1274. DOI: 10.1007/978-90-481-2746-7_71. [16] HU Y B, CONG W L. A review on laser deposition-additive manufacturing of ceramics and ceramic reinforced metal matrix composites [J]. Ceramics International, 2018, 44(17): 20599–20612. DOI: 10.1016/j.ceramint.2018.08.083. [17] ALAGHMANDFARD R, CHALASANI D, HADADZADEH A, et al. Dynamic compressive response of electron beam melted Ti–6Al–4V under elevated strain rates: microstructure and constitutive models [J]. Additive Manufacturing, 2020, 35: 101347. DOI: 10.1016/j.addma.2020.101347. [18] KOLAMROUDI M K, ASMAEL M, ILKAN M, et al. Developments on Electron Beam Melting (EBM) of Ti-6Al-4V: a review [J]. Transactions of the Indian Institute of Metals, 2021, 74(4): 783–790. DOI: 10.1007/s12666-021-02230-9. [19] DOÑATE-BUENDÍA C, KÜRNSTEINER P, STERN F, et al. Microstructure formation and mechanical properties of ODS steels built by laser additive manufacturing of nanoparticle coated iron-chromium powders [J]. Acta Materialia, 2021, 206: 116566. DOI: 10.1016/j.actamat.2020.116566. [20] 刘晏硕, 徐诺, 徐国建, 等. Nb对激光增材制造TC4沉积态组织与性能的影响 [J]. 热加工工艺, 2024, 53(7): 41–46. DOI: 10.14158/j.cnki.1001-3814.20213413.LIU Y S, XU N, XU G J, et al. Effect of Nb on microstructure and properties of laser additive manufacturing TC4 in deposited state [J]. Hot Working Technology, 2024, 53(7): 41–46. DOI: 10.14158/j.cnki.1001-3814.20213413. [21] WEI B C, CHEN W G, GUO S L, et al. Study on the tribological characteristics of surface triangular textured TC4 alloy prepared by SLM technology [J]. Surface and Coatings Technology, 2024, 482: 130735. DOI: 10.1016/j.surfcoat.2024.130735. [22] LI S J, MURR L E, CHENG X Y, et al. Compression fatigue behavior of Ti-6Al-4V mesh arrays fabricated by electron beam melting [J]. Acta Materialia, 2012, 60(3): 793–802. DOI: 10.1016/j.actamat.2011.10.051. [23] ARRIETA E. Comprehensive finite element modeling of Ti-6Al-4V cellular solids fabricated by electron beam melting [D]. Texas: University of Texas at El Paso, 2017: 34–35. [24] GOKULDOSS P K, KOLLA S, ECKERT J. Additive manufacturing processes: selective laser melting, electron beam melting and binder jetting: selection guidelines [J]. Materials, 2017, 10(6): 672. DOI: 10.3390/ma10060672. [25] QIU C L, KINDI M A, ALADAWI A S, et al. A comprehensive study on microstructure and tensile behaviour of a selectively laser melted stainless steel [J]. Scientific Reports, 2018, 8(1): 7785. DOI: 10.1038/s41598-018-26136-7. [26] DAS M, BALLA V K, BASU D, et al. Laser processing of SiC-particle-reinforced coating on titanium [J]. Scripta Materialia, 2010, 63(4): 438–441. DOI: 10.1016/j.scriptamat.2010.04.044. [27] AL-BERMANI S S, BLACKMORE M L, ZHANG W, et al. The origin of microstructural diversity, texture, and mechanical properties in electron beam melted Ti-6Al-4V [J]. Metallurgical and Materials Transactions A, 2010, 41(13): 3422–3434. DOI: 10.1007/s11661-010-0397-x. [28] SHIPLEY H, MCDONNELL D, CULLETON M, et al. Optimisation of process parameters to address fundamental challenges during selective laser melting of Ti-6Al-4V: a review [J]. International Journal of Machine Tools and Manufacture, 2018, 128: 1–20. DOI: 10.1016/j.ijmachtools.2018.01.003. [29] ALI H, GHADBEIGI H, MUMTAZ K. Effect of scanning strategies on residual stress and mechanical properties of selective laser melted Ti6Al4V [J]. Materials Science and Engineering: A, 2018, 712: 175–187. DOI: 10.1016/j.msea.2017.11.103. [30] LIU Z, ZHAO Z B, LIU J R, et al. Effect of α texture on the tensile deformation behavior of Ti–6Al–4V alloy produced via electron beam rapid manufacturing [J]. Materials Science and Engineering: A, 2019, 742: 508–516. DOI: 10.1016/j.msea.2018.11.012. [31] HAO Y L, LI S J, YANG R. Biomedical titanium alloys and their additive manufacturing [J]. Rare Metals, 2016, 35(9): 661–671. DOI: 10.1007/s12598-016-0793-5. [32] VRANCKEN B, THIJS L, KRUTH J P, et al. Heat treatment of Ti6Al4V produced by selective laser melting: microstructure and mechanical properties [J]. Journal of Alloys and Compounds, 2012, 541: 177–185. DOI: 10.1016/j.jallcom.2012.07.022. [33] REDA R, NOFAL A, HUSSEIN A H. Effect of single and duplex stage heat treatment on the microstructure and mechanical properties of cast Ti-6Al-4V Alloy [J]. Metallography, Microstructure, and Analysis, 2013, 2(6): 388–393. DOI: 10.1007/s13632-013-0103-7. [34] LIU C M, LU Y, TIAN X J, et al. Influence of continuous grain boundary α on ductility of laser melting deposited titanium alloys [J]. Materials Science and Engineering: A, 2016, 661: 145–151. DOI: 10.1016/j.msea.2016.03.034. [35] SHRESTHA S, PANAKARAJUPALLY R P, KANNAN M, et al. Analysis of microstructure and mechanical properties of additive repaired Ti–6Al–4V by direct energy deposition [J]. Materials Science and Engineering: A, 2021, 806: 140604. DOI: 10.1016/j.msea.2020.140604. [36] ÅKERFELDT P, ANTTI M L, PEDERSON R. Influence of microstructure on mechanical properties of laser metal wire-deposited Ti-6Al-4V [J]. Materials Science and Engineering: A, 2016, 674: 428–437. DOI: 10.1016/j.msea.2016.07.038. [37] BANERJEE D, WILLIAMS J C. Perspectives on titanium science and technology [J]. Acta Materialia, 2013, 61(3): 844–879. DOI: 10.1016/j.actamat.2012.10.043. [38] DUCATO A, FRATINI L, LA CASCIA M, et al. An automated visual inspection system for the classification of the phases of Ti-6Al-4V titanium alloy [C]//15th International Conference on Computer Analysis of Images and Patterns. York: Springer, 2013. DOI: 10.1007/978-3-642-40246-3_45. [39] AHMED T, RACK H J. Phase transformations during cooling in α+β titanium alloys [J]. Materials Science and Engineering: A, 1998, 243(1/2): 206–211. DOI: 10.1016/S0921-5093(97)00802-2. [40] GIL MUR F X, RODRÍGUEZ D, PLANELL J A. Influence of tempering temperature and time on the α-Ti-6Al-4V martensite [J]. Journal of Alloys and Compounds, 1996, 234(2): 287–289. DOI: 10.1016/0925-8388(95)02057-8. [41] ZHAI Y W, GALARRAGA H, LADOS D A. Microstructure, static properties, and fatigue crack growth mechanisms in Ti-6Al-4V fabricated by additive manufacturing: LENS and EBM [J]. Engineering Failure Analysis, 2016, 69: 3–14. DOI: 10.1016/j.engfailanal.2016.05.036. [42] SAFDAR A, WEI L Y, SNIS A, et al. Evaluation of microstructural development in electron beam melted Ti-6Al-4V [J]. Materials Characterization, 2012, 65: 8–15. DOI: 10.1016/j.matchar.2011.12.008. [43] GALARRAGA H, LADOS D A, DEHOFF R R, et al. Effects of the microstructure and porosity on properties of Ti-6Al-4V ELI alloy fabricated by electron beam melting (EBM) [J]. Additive Manufacturing, 2016, 10: 47–57. DOI: 10.1016/j.addma.2016.02.003. [44] LI J Q, LIN X, WANG J, et al. Effect of stress-relief annealing on anodic dissolution behaviour of additive manufactured Ti-6Al-4V via laser solid forming [J]. Corrosion Science, 2019, 153: 314–326. DOI: 10.1016/j.corsci.2019.04.002. [45] 从保强, 丁佳洛. CMT工艺对Al-Cu合金电弧增材制造气孔的影响 [J]. 稀有金属材料与工程, 2014, 43(12): 3149–3153. DOI: CNKI:SUN:COSE.0.2014-12-056.CONG B Q, DING J L. Influence of CMT process on porosity of wire arc additive manufactured Al-Cu alloy [J]. Rare Metal Materials and Engineering, 2014, 43(12): 3149–3153. DOI: CNKI:SUN:COSE.0.2014-12-056. [46] LI P H, GUO W G, HUANG W D, et al. Thermomechanical response of 3D laser-deposited Ti-6Al-4V alloy over a wide range of strain rates and temperatures [J]. Materials Science and Engineering: A, 2015, 647: 34–42. DOI: 10.1016/j.msea.2015.08.043. [47] 权国政, 杨焜, 盛雪, 等. 电弧熔丝增材制造残余应力控制方法综述 [J]. 塑性工程学报, 2021, 28(11): 1–10. DOI: 10.3969/j.issn.1007-2012.2021.11.001.QUAN G Z, YANG K, SHENG X, et al. A review of control method for residual stress of wire and arc additive manufacturing [J]. Journal of Plasticity Engineering, 2021, 28(11): 1–10. DOI: 10.3969/j.issn.1007-2012.2021.11.001. [48] 赵剑峰, 谢德巧, 梁绘昕, 等. 金属增材制造变形与残余应力的研究现状 [J]. 南京航空航天大学学报, 2019, 51(1): 1–6. DOI: 10.16356/j.1005-2615.2019.01.001.ZHAO J F, XIE D Q, LIANG H X, et al. Review of distortion and residual stress in metal additive manufacturing [J]. Journal of Nanjing University of Aeronautics and Astronautics, 2019, 51(1): 1–6. DOI: 10.16356/j.1005-2615.2019.01.001. [49] JAVIDRAD H R, GHANBARI M, JAVIDRAD F. Effect of scanning pattern and volumetric energy density on the properties of selective laser melting Ti-6Al-4V specimens [J]. Journal of Materials Research and Technology, 2021, 12: 989–998. DOI: 10.1016/j.jmrt.2021.03.044. [50] QIAN M, XU W, BRANDT M, et al. Additive manufacturing and postprocessing of Ti-6Al-4V for superior mechanical properties [J]. MRS Bulletin, 2016, 41(10): 775–784. DOI: 10.1557/mrs.2016.215. [51] FATEMI A, MOLAEI R, SIMSIRIWONG J, et al. Fatigue behaviour of additive manufactured materials: an overview of some recent experimental studies on Ti-6Al-4V considering various processing and loading direction effects [J]. Fatigue and Fracture of Engineering Materials and Structures, 2019, 42(5): 991–1009. DOI: 10.1111/ffe.13000. [52] SIMONELLI M, TSE Y Y, TUCK C. Effect of the build orientation on the mechanical properties and fracture modes of SLM Ti–6Al–4V [J]. Materials Science and Engineering: A, 2014, 616: 1–11. DOI: 10.1016/j.msea.2014.07.086. [53] WYSOCKI B, MAJ P, SITEK R, et al. Laser and electron beam additive manufacturing methods of fabricating titanium bone implants [J]. Applied Sciences, 2017, 7(7): 657. DOI: 10.3390/app7070657. [54] LIU Y, PANG Z C, LI M, et al. Investigation into the dynamic mechanical properties of selective laser melted Ti-6Al-4V alloy at high strain rate tensile loading [J]. Materials Science and Engineering: A, 2019, 745: 440–449. DOI: 10.1016/j.msea.2019.01.010. [55] ZHAO Z, CHEN J, LU X F, et al. Formation mechanism of the α variant and its influence on the tensile properties of laser solid formed Ti-6Al-4V titanium alloy [J]. Materials Science and Engineering: A, 2017, 691: 16–24. DOI: 10.1016/j.msea.2017.03.035. [56] ZHU Y Y, LI J, TIAN X J, et al. Microstructure and mechanical properties of hybrid fabricated Ti–6.5Al–3.5Mo–1.5Zr–0.3Si titanium alloy by laser additive manufacturing [J]. Materials Science and Engineering: A, 2014, 607: 427–434. DOI: 10.1016/j.msea.2014.04.019. [57] ZHOU Y G, ZENG W D, YU H Q. An investigation of a new near-beta forging process for titanium alloys and its application in aviation components [J]. Materials Science and Engineering: A, 2005, 393(1/2): 204–212. DOI: 10.1016/j.msea.2004.10.016. [58] LEI L, ZHAO Y Q, ZHAO Q Y, et al. Impact toughness and deformation modes of Ti–6Al–4V alloy with different microstructures [J]. Materials Science and Engineering: A, 2021, 801: 140411. DOI: 10.1016/j.msea.2020.140411. [59] ZHAO Z, CHEN J, TAN H, et al. Achieving superior ductility for laser solid formed extra low interstitial Ti-6Al-4V titanium alloy through equiaxial alpha microstructure [J]. Scripta Materialia, 2018, 146: 187–191. DOI: 10.1016/j.scriptamat.2017.11.021. [60] REN H S, TIAN X J, LIU D, et al. Microstructural evolution and mechanical properties of laser melting deposited Ti-6.5Al-3.5Mo-1.5Zr-0.3Si titanium alloy [J]. Transactions of Nonferrous Metals Society of China, 2015, 25(6): 1856–1864. DOI: 10.1016/S1003-6326(15)63792-X. [61] MERCELIS P, KRUTH J P. Residual stresses in selective laser sintering and selective laser melting [J]. Rapid Prototyping Journal, 2006, 12(5): 254–265. DOI: 10.1108/13552540610707013. [62] LIU Y, YANG Y Q, WANG D. A study on the residual stress during selective laser melting (SLM) of metallic powder [J]. The International Journal of Advanced Manufacturing Technology, 2016, 87(1/2/3/4): 647–656. DOI: 10.1007/s00170-016-8466-y. [63] VRANCKEN B, CAIN V, KNUTSEN R, et al. Residual stress via the contour method in compact tension specimens produced via selective laser melting [J]. Scripta Materialia, 2014, 87: 29–32. DOI: 10.1016/j.scriptamat.2014.05.016. [64] YADROITSAVA I, GREWAR S, HATTINGH D, et al. Residual stress in SLM Ti6Al4V alloy specimens [J]. Materials Science Forum, 2015, 828/829: 305–310. DOI: 10.4028/www.scientific.net/MSF.828-829.305. [65] HRABE N, GNÄUPEL-HEROLD T, QUINN T. Fatigue properties of a titanium alloy (Ti-6Al-4V) fabricated via electron beam melting (EBM): effects of internal defects and residual stress [J]. International Journal of Fatigue, 2017, 94: 202–210. DOI: 10.1016/j.ijfatigue.2016.04.022. [66] YANG J J, YU H C, YIN J, et al. Formation and control of martensite in Ti-6Al-4V alloy produced by selective laser melting [J]. Materials & Design, 2016, 108: 308–318. DOI: 10.1016/j.matdes.2016.06.117. [67] 陈欢, 孙新军, 王小江, 等. 高锰奥氏体低温钢力学性能及Hall-Petch关系的研究 [J]. 材料科学与工艺, 2018, 26(5): 11–18. DOI: 10.11951/j.issn.1005-0299.20170425.CHEN H, SUN X J, WANG X J, et al. Mechanical properties and Hall-Petch relationship of high manganese austenitic cryogenic steel [J]. Materials Science and Technology, 2018, 26(5): 11–18. DOI: 10.11951/j.issn.1005-0299.20170425. [68] BAUFELD B, VAN DER BIEST O. Mechanical properties of Ti-6Al-4V specimens produced by shaped metal deposition [J]. Science and Technology of Advanced Materials, 2009, 10(1): 015008. DOI: 10.1088/1468-6996/10/1/015008. [69] WU C, ZHAO Y Q, HUANG S X, et al. Microstructure tailoring and impact toughness of a newly developed high strength Ti-5Al-3Mo-3V-2Cr-2Zr-1Nb-1Fe alloy [J]. Materials Characterization, 2021, 175: 111103. DOI: 10.1016/j.matchar.2021.111103. [70] SAUER C, LÜETJERING G. Processing, microstructure and properties of Ti-6246[C]//Titanium'99: Science and Technology. Saint-Petersburg, Russia, 2000: 390−397. [71] XIE Z Y, DAI Y, OU X Q, et al. Effects of selective laser melting build orientations on the microstructure and tensile performance of Ti–6Al–4V alloy [J]. Materials Science and Engineering: A, 2020, 776: 139001. DOI: 10.1016/j.msea.2020.139001. [72] XU W, BRANDT M, SUN S, et al. Additive manufacturing of strong and ductile Ti–6Al–4V by selective laser melting via in situ martensite decomposition [J]. Acta Materialia, 2015, 85: 74–84. DOI: 10.1016/j.actamat.2014.11.028. [73] XU W, LUI E W, PATERAS A, et al. In situ tailoring microstructure in additively manufactured Ti-6Al-4V for superior mechanical performance [J]. Acta Materialia, 2017, 125: 390–400. DOI: 10.1016/j.actamat.2016.12.027. [74] 白澄岩, 兰亮, 辛如意, 等. 增材制造Ti-6Al-4V钛合金低周疲劳性能研究进展 [J]. 材料科学与工艺, 2023, 31(1): 79–90. DOI: 10.11951/j.issn.1005-0299.20220054.BAI C Y, LAN L, XIN R Y, et al. Research progress on low-cycle fatigue properties of Ti-6Al-4V alloy by additive manufacturing [J]. Materials Science and Technology, 2023, 31(1): 79–90. DOI: 10.11951/j.issn.1005-0299.20220054. [75] 杜子杰, 李文渊, 刘建荣, 等. CMT增材制造TC4-DT合金组织均匀性与力学性能一致性研究 [J]. 金属学报, 2020, 56(12): 1667–1680. DOI: 10.11900/0412.1961.2020.00104.DU Z J, LI W Y, LIU J R, et al. Study on the uniformity of structure and mechanical properties of TC4-DT alloy deposited by CMT process [J]. Acta Metallurgica Sinica, 2020, 56(12): 1667–1680. DOI: 10.11900/0412.1961.2020.00104. [76] CHEN R, TAN C W, YOU Z Y, et al. Effect of α phase on high-strain rate deformation behavior of laser melting deposited Ti-6.5Al-1Mo-1V-2Zr titanium alloy [J]. Materials Science and Engineering: A, 2019, 750: 81–90. DOI: 10.1016/j.msea.2019.01.060. [77] ZHU Y Y, TIAN X J, LI J, et al. The anisotropy of laser melting deposition additive manufacturing Ti-6.5Al-3.5Mo-1.5Zr-0.3Si titanium alloy [J]. Materials and Design, 2015, 67: 538–542. DOI: 10.1016/j.matdes.2014.11.001. [78] BENMESSAOUD F, CHEIKH M, VELAY V, et al. Role of grain size and crystallographic texture on tensile behavior induced by sliding mechanism in Ti-6Al-4V alloy [J]. Materials Science and Engineering: A, 2020, 774: 138835. DOI: 10.1016/j.msea.2019.138835. [79] LI H, MASON D E, BIELER T R, et al. Methodology for estimating the critical resolved shear stress ratios of α-phase Ti using EBSD-based trace analysis [J]. Acta Materialia, 2013, 61(20): 7555–7567. DOI: 10.1016/j.actamat.2013.08.042. [80] BRIDIER F, VILLECHAISE P, MENDEZ J. Analysis of the different slip systems activated by tension in a α/β titanium alloy in relation with local crystallographic orientation [J]. Acta Materialia, 2005, 53(3): 555–567. DOI: 10.1016/j.actamat.2004.09.040. [81] KISHIDA K, KIM J G, NAGAE T, et al. Experimental evaluation of critical resolved shear stress for the first-order pyramidal c + a slip in commercially pure Ti by micropillar compression method [J]. Acta Materialia, 2020, 196: 168–174. DOI: 10.1016/j.actamat.2020.06.043. [82] JIN N, YAN Z Y, WANG Y W, et al. Effects of heat treatment on microstructure and mechanical properties of selective laser melted Ti-6Al-4V lattice materials [J]. International Journal of Mechanical Sciences, 2021, 190: 106042. DOI: 10.1016/j.ijmecsci.2020.106042. [83] FANG M H, HU F G, HAN Y F, et al. Controllable mechanical anisotropy of selective laser melted Ti6Al4V: a new perspective into the effect of grain orientations and primary grain structure [J]. Materials Science and Engineering: A, 2021, 827: 142031. DOI: 10.1016/j.msea.2021.142031. [84] 贺韡, 雷文杰, 彭丹迪. 去应力退火对TB15钛合金力学性能和组织的影响 [J]. 热加工工艺, 2021, 50(24): 146–148,145. DOI: 10.14158/j.cnki.1001-3814.20212745.HE W, LEI W J, PENG D D. Effects of stress-relief annealing on mechanical properties and microstructure of TB15 titanium alloy [J]. Hot Working Technology, 2021, 50(24): 146–148,145. DOI: 10.14158/j.cnki.1001-3814.20212745. [85] 高星, 张宁, 丁燕, 等. 热处理时间对激光选区成形TC4钛合金组织及力学性能的影响 [J]. 金属热处理, 2022, 47(9): 12–17. DOI: 10.13251/j.issn.0254-6051.2022.09.003.GAO X, ZHANG N, DING Y, et al. Effect of heat treatment time on microstructure and mechanical properties of TC4 titanium alloy fabricated by selective laser melting [J]. Heat Treatment of Metals, 2022, 47(9): 12–17. DOI: 10.13251/j.issn.0254-6051.2022.09.003. [86] 孙兵兵, 闫泰起, 陈冰清, 等. 选区激光熔化TC4钛合金组织性能调控热处理工艺 [J]. 焊接技术, 2023, 52(6): 1–6. DOI: 10.13846/j.cnki.cn12-1070/tg.2023.06.030.SUN B B, YAN T Q, CHEN B Q, et al. Heat treatment process for optimization of the microstructure and mechanical properties of selective laser melting TC4 titanium alloy [J]. Welding Technology, 2023, 52(6): 1–6. DOI: 10.13846/j.cnki.cn12-1070/tg.2023.06.030. [87] 张元东, 张安, 车安达, 等. β退火的低温退火温度对TC32合金组织和性能的影响 [J]. 锻造与冲压, 2023(11): 61–66. [88] YU H C, YANG J J, YIN J, et al. Comparison on mechanical anisotropies of selective laser melted Ti-6Al-4V alloy and 304 stainless steel [J]. Materials Science and Engineering: A, 2017, 695: 92–100. DOI: 10.1016/j.msea.2017.04.031. [89] WU M W, NI K, YEN H W, et al. Revealing the intensified preferred orientation and factors dominating the anisotropic mechanical properties of laser powder bed fusion Ti-6Al-4V alloy after heat treatment [J]. Journal of Alloys and Compounds, 2023, 949: 169494. DOI: 10.1016/j.jallcom.2023.169494. [90] GAO X X, TAO C H, WU S J, et al. Influence of modified microstructures and characterized defects on tensile properties and anisotropy of selective laser melting-produced Ti6Al4V alloys [J]. Journal of Materials Engineering and Performance, 2022, 31(9): 7705–7718. DOI: 10.1007/s11665-022-06745-0. [91] CAO S, CHEN Z E, LIM C V S, et al. Defect, microstructure, and mechanical property of Ti-6Al-4V alloy fabricated by high-power selective laser melting [J]. JOM, 2017, 69(12): 2684–2692. DOI: 10.1007/s11837-017-2581-6. [92] HUANG W D, HE D D, WANG H, et al. The effect of heat treatment on the anisotropy of Ti-6Al-4V by selective laser melting [J]. JOM, 2022, 74(7): 2724–2732. DOI: 10.1007/s11837-022-05212-4. [93] VILARO T, COLIN C, BARTOUT J D. As-fabricated and heat-treated microstructures of the Ti-6Al-4V alloy processed by selective laser melting [J]. Metallurgical and Materials Transactions A, 2011, 42(10): 3190–3199. DOI: 10.1007/s11661-011-0731-y. [94] MEIER B, GODJA N, WARCHOMICKA F, et al. Influences of surface, heat treatment, and print orientation on the anisotropy of the mechanical properties and the impact strength of Ti 6Al 4V processed by laser powder bed fusion [J]. Journal of Manufacturing and Materials Processing, 2022, 6(4): 87. DOI: 10.3390/jmmp6040087. [95] LIU J W, LIU J, LI Y X, et al. Effects of post heat treatments on microstructures and mechanical properties of selective laser melted Ti6AL4V alloy [J]. Metals, 2021, 11(10): 1593. DOI: 10.3390/met11101593. [96] CHANG K, WANG X, LIANG E Q, et al. On the texture and mechanical property anisotropy of Ti6Al4V alloy fabricated by powder-bed based laser additive manufacturing [J]. Vacuum, 2020, 181: 109732. DOI: 10.1016/j.vacuum.2020.109732. [97] AL-RUBAIE K S, MELOTTI S, RABELO A, et al. Machinability of SLM-produced Ti6Al4V titanium alloy parts [J]. Journal of Manufacturing Processes, 2020, 57: 768–786. DOI: 10.1016/j.jmapro.2020.07.035. [98] 冉春, 陈鹏万, 李玲, 等. 中高应变率条件下TC18钛合金动态力学行为的实验研究 [J]. 兵工学报, 2017, 38(9): 1723–1728. DOI: 10.3969/j.issn.1000-1093.2017.09.008.RAN C, CHEN P W, LI L, et al. Experimental research on dynamic mechanical behavior of TC18 titanium alloy under medium and high strain rates [J]. Acta Armamentarii, 2017, 38(9): 1723–1728. DOI: 10.3969/j.issn.1000-1093.2017.09.008. [99] CHENG F, WANG H M, LI Z, et al. Dynamic compression deformation behavior of laser directed energy deposited α+β duplex titanium alloy with basket-weave morphology [J]. Additive Manufacturing, 2023, 61: 103336. DOI: 10.1016/j.addma.2022.103336. [100] LU G, YU T X. Energy absorption of structures and materials[M]. London: Elsevier Science, 2003: 19-22. [101] ZHAO S H, YUAN K B, GUO W G, et al. A comparative study of laser metal deposited and forged Ti-6Al-4V alloy: uniaxial mechanical response and vibration fatigue properties [J]. International Journal of Fatigue, 2020, 136: 105629. DOI: 10.1016/j.ijfatigue.2020.105629. [102] 张世进, 李凯, 易丹青, 等. 冷轧TA5钛合金退火过程的再结晶行为及织构演变 [J]. 金属热处理, 2022, 47(2): 1–8. DOI: 10.13251/j.issn.0254-6051.2022.02.001.ZHANG S J, LI K, YI D Q, et al. Recrystallization behavior and texture evolution of cold rolled TA5 titanium alloy during annealing [J]. Heat Treatment of Metals, 2022, 47(2): 1–8. DOI: 10.13251/j.issn.0254-6051.2022.02.001. [103] WAYMEL R F, CHEW H B, LAMBROS J. Loading orientation effects on the strength anisotropy of additively-manufactured Ti-6Al-4V alloys under dynamic compression [J]. Experimental Mechanics, 2019, 59(6): 829–841. DOI: 10.1007/s11340-019-00506-2. [104] RODRIGUEZ O L, ALLISON P G, WHITTINGTON W R, et al. Strain rate effect on the tension and compression stress-state asymmetry for electron beam additive manufactured Ti6Al4V [J]. Materials Science and Engineering: A, 2018, 713: 125–133. DOI: 10.1016/j.msea.2017.12.062. [105] JIANG X J, CHEN G Y, MEN X L, et al. Grain refinement and excellent mechanical properties of a Ti-based alloy via laser melting and subsequent low temperature annealing [J]. Materials Science and Engineering: A, 2018, 737: 182–187. DOI: 10.1016/j.msea.2018.09.042. [106] PANG Z C, LIU Y, LI M, et al. Influence of process parameter and strain rate on the dynamic compressive properties of selective laser-melted Ti-6Al-4V alloy [J]. Applied Physics A, 2019, 125(2): 90. DOI: 10.1007/s00339-018-2359-x. [107] DIXIT T, SAHU P K, JONNALAGADDA K, et al. Effect of powder layer thickness and scan orientation on the deformation and failure of selectively laser melted Ti-6Al-4V alloy over six decades of strain rates [J]. Materials Science and Engineering: A, 2021, 822: 141656. DOI: 10.1016/j.msea.2021.141656. [108] ALAGHMANDFARD R, CHALASANI D, ODESHI A G, et al. Microstructure and mechanical properties of Ti-6Al-4V parts fabricated by electron beam melting under dynamic compression tests [C]//Canadian Society for Mechanical Engineering International Congress. Charlottetown, Canada, 2020. DOI: 10.32393/csme.2020.1190. [109] 陈钰浩, 闵小华, 张海洋, 等. TC17和TC4合金锻件的动态响应及绝热剪切行为 [J]. 航空材料学报, 2023, 43(5): 39–49. DOI: 10.11868/j.issn.1005-5053.2023.000105.CHEN Y H, MIN X H, ZHANG H Y, et al. Dynamic responses and adiabatic shear behaviors of TC17 and TC4 alloy forgings [J]. Journal of Aeronautical Materials, 2023, 43(5): 39–49. DOI: 10.11868/j.issn.1005-5053.2023.000105. [110] 余东辉, 范群波, 王富耻, 等. 铸造态钛合金力学性能及抗弹性能研究 [J]. 稀有金属材料与工程, 2017, 46(8): 2234–2239.YU D H, FAN Q B, WANG F C, et al. Mechanical properties and ballistic performance of as-cast titanium alloys [J]. Rare Metal Materials and Engineering, 2017, 46(8): 2234–2239. [111] 黄均毅, 杨扬. 选区电子束熔炼Ti-6Al-4V钛合金的绝热剪切各向异性 [J]. 矿冶工程, 2022, 42(5): 143–147. DOI: 10.3969/j.issn.0253-6099.2022.05.033.HUANG J Y, YANG Y. Anisotropic behavior of adiabatic shear band in Ti-6Al-4V titanium alloy fabricated by selected electron beam melting [J]. Mining and Metallurgical Engineering, 2022, 42(5): 143–147. DOI: 10.3969/j.issn.0253-6099.2022.05.033. [112] PU B, LI W B, ZHANG Q, et al. Research on the dynamic compressive deformation behavior of 3D-printed Ti6Al4V [J]. Metals, 2021, 11(8): 1327. DOI: 10.3390/met11081327. [113] WANG S Q, LIU J H, CHEN D L. Effect of strain rate and temperature on strain hardening behavior of a dissimilar joint between Ti-6Al-4V and Ti17 alloys [J]. Materials and Design (1980-2015), 2014, 56: 174–184. DOI: 10.1016/j.matdes.2013.11.003. [114] RODRIGUEZ O L, ALLISON P G, WHITTINGTON W R, et al. Dynamic tensile behavior of electron beam additive manufactured Ti6Al4V [J]. Materials Science and Engineering: A, 2015, 641: 323–327. DOI: 10.1016/j.msea.2015.06.069. [115] TREVISAN F, CALIGNANO F, LORUSSO M, et al. On the selective laser melting (SLM) of the AlSi10Mg alloy: process, microstructure, and mechanical properties [J]. Materials (Basel), 2017, 10(1): 76. DOI: 10.3390/ma10010076. [116] 张斌, 郭玲梅, 汪洋, 等. TA7钛合金拉伸和压缩加载时的孪生变形行为 [J]. 中国有色金属学报, 2021, 31(9): 2427–2435. DOI: 10.11817/j.ysxb.1004.0609.2021-39781.ZHANG B, GUO L M, WANG Y, et al. Deformation twinning behavior of TA7 titanium alloy under tension and compression [J]. The Chinese Journal of Nonferrous Metals, 2021, 31(9): 2427–2435. DOI: 10.11817/j.ysxb.1004.0609.2021-39781. [117] 闫辰侃, 曲寿江, 冯艾寒, 等. 钛及钛合金形变孪晶的研究进展 [J]. 稀有金属, 2019, 43(5): 449–460. DOI: 10.13373/j.cnki.cjrm.xy18040028.YAN C K, QU S J, FENG A H, et al. Recent advances of deformation twins in titanium and titanium alloys [J]. Chinese Journal of Rare Metals, 2019, 43(5): 449–460. DOI: 10.13373/j.cnki.cjrm.xy18040028. [118] ALAGHMANDFARD R, DHARMENDRA C, ODESHI A G, et al. Dynamic mechanical properties and failure characteristics of electron beam melted Ti-6Al-4V under high strain rate impact loadings [J]. Materials Science and Engineering: A, 2020, 793: 139794. DOI: 10.1016/j.msea.2020.139794. [119] 陈冠方, 张金勇, 钟艺, 等. 相变/孪晶诱发塑性的β钛合金加工硬化行为研究 [J]. 稀有金属材料与工程, 2020, 49(1): 297–303.CHEN G F, ZHANG J Y, ZHONG Y, et al. Stain-hardening behavior of a ductile beta Ti-alloy with transformation induced plasticity and twinning induced plasticity [J]. Rare Metal Materials and Engineering, 2020, 49(1): 297–303. -