退火温度对激光选区熔化成形TC4钛合金组织及力学性能的影响
|
摘要
采用激光选区熔化技术(SLM)制备TC4钛合金,借助光学显微镜、扫描电镜和万能材料试验机等测试手段,研究了退火温度对TC4钛合金显微组织和力学性能的影响。结果表明:SLM成形TC4样品横截面组织主要由六边形网格分布的等轴晶组成,纵截面主要由外延生长的柱状晶组成,晶粒内部包含大量针状马氏体α'相;随着退火温度的升高,组织内针状马氏体α'相发生分解,α相、β相开始聚集长大,退火温度800℃以上时,组织由魏氏体组织向网篮组织转变;随着退火温度的升高,合金的力学性能宏观呈现强度下降,伸长率上升的规律。综合比较几种退火制度发现,800℃×2 h/FC处理后的TC4合金获得相对最佳的综合力学性能。
TC4 titanium alloy was prepared by selective laser melting technique( SLM), the effect of annealing temperature on microstructure and mechanical properties of TC4 titanium alloy was studied by means of optical microscope,scanning electron microscope and universal material testing machine. The results show that the cross section of the TC4 samples is mainly composed of hexagonal equiaxed crystals,the longitudinal sections are mainly composed of epitaxial columnar crystals,and a large number of acicular martensite α' phases are found in the grains. With the increase of annealing temperature,the α' phase of acicular martensite begins to decompose,the α phase and β phase begin to gather and grow. When the temperature is above 800 ℃,the whole microstructure begins to change from widmanstatten structure to net-basket structure; with the increase of annealing temperature,the mechanical properties of the alloy show the law of decreasing strength and increasing elongation. By comparing several annealing systems,it is found that the TC4 alloy treated at 800 ℃ × 2 h/FC will obtain the best comprehensive mechanical properties.
TC4 titanium alloy was prepared by selective laser melting technique( SLM), the effect of annealing temperature on microstructure and mechanical properties of TC4 titanium alloy was studied by means of optical microscope,scanning electron microscope and universal material testing machine. The results show that the cross section of the TC4 samples is mainly composed of hexagonal equiaxed crystals,the longitudinal sections are mainly composed of epitaxial columnar crystals,and a large number of acicular martensite α' phases are found in the grains. With the increase of annealing temperature,the α' phase of acicular martensite begins to decompose,the α phase and β phase begin to gather and grow. When the temperature is above 800 ℃,the whole microstructure begins to change from widmanstatten structure to net-basket structure; with the increase of annealing temperature,the mechanical properties of the alloy show the law of decreasing strength and increasing elongation. By comparing several annealing systems,it is found that the TC4 alloy treated at 800 ℃ × 2 h/FC will obtain the best comprehensive mechanical properties.
引文
[1]Zhao X,Li S,Zhang M,et al.Comparison of the microstructures and mechanical properties of Ti-6Al-4V fabricated by selective laser melting and electron beam melting[J].Materials and Design,2016,95:21-31.
[2]Karlsson J,Snis A,Engqvist H,et al.Characterization and comparison of materials produced by electron beam melting(EBM)of two different Ti-6Al-4V powder fractions[J].Journal of Materials Processing Technology,2013,213(12):2109-2118.
[3]Li H,Huang B,Fan S,et al.Microstructure and tensile properties of Ti-6Al-4V alloys fabricated by selective laser melting[J].Rare Metal Materials and Engineering,2013,42:209-212.
[4]付立定.不锈钢粉末选择性激光熔化直接制造金属零件研究[D].武汉:华中科技大学,2008.
[5]Zhang L C,Attar H,Calin M,et al.Review on manufacture by selective laser melting and properties of titanium based materials for biomedical applications[J].Materials and Processing Report,2016,31(2):66-76.
[6]Murr L E,Martinez E,Amato K N,et al.Fabrication of metal and alloy components by additive manufacturing:examples of 3D materials science[J].Journal of Materials Research and Technology,2012,1(1):42-54.
[7]Thijs L,Verhaeghe F,Craeghs T,et al.A study of the microstructural evolution during selective laser melting of Ti-6Al-4V[J].Acta Materialia,2010,58(9):3303-3312.
[8]张霜银,林鑫,陈静,等.热处理对激光立体成形TC4残余应力的影响[J].稀有金属材料与工程,2009,38(5):774-778.Zhang Shuangyin,Lin Xin,Chen Jing,et al.Influence of heat treatment on residual stress of Ti-6Al-4V alloy by laser solid forming[J].Rare Metal Materials and Engineering,2009,38(5):774-778.
[9]张霜银,林鑫,陈静,等.热处理对激光成形TC4合金组织及性能的影响[J].稀有金属材料与工程,2007,36(7):1263-1266.Zhang Shuangyin,Lin Xin,Chen Jing,et al.Influence of heat treatment on the microstructure and properties of Ti-6Al-4V titanium alloy by laser rapid forming[J].Rare Metal Materials and Engineering,2007,36(7):1263-1266.
[10]肖振楠,刘婷婷,廖文和,等.激光选区熔化成形TC4钛合金热处理后微观组织和力学性能[J].中国激光,2017,44(9):81-89.Xiao Zhennan,Liu Tingting,Liao Wenhe,et al.Microstructure and mechanical properties of TC4 titanium alloy formed by selective laser melting after heat treatment[J].Chinese Journal of Lasers,2017,44(9):81-89.
[11]Vrancken B,Thijs L,Kruth J P,et al.Heat treatment of Ti6Al4Vproduced by selective laser melting:microstructure and mechanical properties[J].Journal of Alloys and Compounds,2012,541:177-185.
[12]李文贤,易丹青,刘会群,等.热处理制度对选择性激光熔化成形TC4钛合金的组织与力学性能的影响[J].粉末冶金材料科学与工程,2017,22(1):70-78.Li Wenxian,Yi Danqing,Liu Huiqun,et al.Effect of the heat treatment process on microstructure and mechanical properties of the TC4 alloy processed by selective laser melting[J].Materials Science and Engineering of Powder Metallurgy,2017,22(1):70-78.
[13]蒋军杰.选区激光熔化成型医用Ti-6Al-4V合金的组织和性能研究[D].重庆:重庆大学,2015.
[14]Marlo S,Yau T Y,Tuck C.The formation ofα+βmicrostructure in as-fabricated selective laser melting of Ti-6Al-4V[J].Journal of Materials Research,2014,29(17):2028-2035.
[15]韩婕.激光选区熔化成形Ti6Al4V合金的各向异性研究[D].武汉:华中科技大学,2016.
[16]陈静,谭华,张凤英.激光快速成形过程的热行为及其影响[J].中国激光,2007,34(S1):171-174.Chen Jing,Tan Hua,Zhang Fengying,et al.Thermal behavior and its effect on the process of laser rapid forming[J].Chinese Journal of Lasers,2007,34(S1):171-174.
[17]李文艺.钛合金激光快速成形熔池凝固晶粒生长机理研究[D].沈阳:沈阳航空航天大学,2016.
[18]钱远宏,谭华,李静,等.高功率激光立体成形Ti-6Al-4V合金组织研究[J].稀有金属材料与工程,2014,43(9):2162-2166.Qian Yuanhong,Tan Hua,Li Jing,et al.Microstructure characterization of laser solid forming Ti-6Al-4V alloy by high power[J].Rare Metal Materials and Engineering,2014,43(9):2162-2166.
[19]周鑫.激光选区熔化微尺度熔池特性与凝固微观组织[D].北京:清华大学,2016.
[20]GJB 2744A-2007,航空用钛及钛合金锻件规范[S].
[21]赵永庆,洪权,葛鹏.钛及钛合金金相图谱[M].长沙:中南大学出版社,2011.
[2]Karlsson J,Snis A,Engqvist H,et al.Characterization and comparison of materials produced by electron beam melting(EBM)of two different Ti-6Al-4V powder fractions[J].Journal of Materials Processing Technology,2013,213(12):2109-2118.
[3]Li H,Huang B,Fan S,et al.Microstructure and tensile properties of Ti-6Al-4V alloys fabricated by selective laser melting[J].Rare Metal Materials and Engineering,2013,42:209-212.
[4]付立定.不锈钢粉末选择性激光熔化直接制造金属零件研究[D].武汉:华中科技大学,2008.
[5]Zhang L C,Attar H,Calin M,et al.Review on manufacture by selective laser melting and properties of titanium based materials for biomedical applications[J].Materials and Processing Report,2016,31(2):66-76.
[6]Murr L E,Martinez E,Amato K N,et al.Fabrication of metal and alloy components by additive manufacturing:examples of 3D materials science[J].Journal of Materials Research and Technology,2012,1(1):42-54.
[7]Thijs L,Verhaeghe F,Craeghs T,et al.A study of the microstructural evolution during selective laser melting of Ti-6Al-4V[J].Acta Materialia,2010,58(9):3303-3312.
[8]张霜银,林鑫,陈静,等.热处理对激光立体成形TC4残余应力的影响[J].稀有金属材料与工程,2009,38(5):774-778.Zhang Shuangyin,Lin Xin,Chen Jing,et al.Influence of heat treatment on residual stress of Ti-6Al-4V alloy by laser solid forming[J].Rare Metal Materials and Engineering,2009,38(5):774-778.
[9]张霜银,林鑫,陈静,等.热处理对激光成形TC4合金组织及性能的影响[J].稀有金属材料与工程,2007,36(7):1263-1266.Zhang Shuangyin,Lin Xin,Chen Jing,et al.Influence of heat treatment on the microstructure and properties of Ti-6Al-4V titanium alloy by laser rapid forming[J].Rare Metal Materials and Engineering,2007,36(7):1263-1266.
[10]肖振楠,刘婷婷,廖文和,等.激光选区熔化成形TC4钛合金热处理后微观组织和力学性能[J].中国激光,2017,44(9):81-89.Xiao Zhennan,Liu Tingting,Liao Wenhe,et al.Microstructure and mechanical properties of TC4 titanium alloy formed by selective laser melting after heat treatment[J].Chinese Journal of Lasers,2017,44(9):81-89.
[11]Vrancken B,Thijs L,Kruth J P,et al.Heat treatment of Ti6Al4Vproduced by selective laser melting:microstructure and mechanical properties[J].Journal of Alloys and Compounds,2012,541:177-185.
[12]李文贤,易丹青,刘会群,等.热处理制度对选择性激光熔化成形TC4钛合金的组织与力学性能的影响[J].粉末冶金材料科学与工程,2017,22(1):70-78.Li Wenxian,Yi Danqing,Liu Huiqun,et al.Effect of the heat treatment process on microstructure and mechanical properties of the TC4 alloy processed by selective laser melting[J].Materials Science and Engineering of Powder Metallurgy,2017,22(1):70-78.
[13]蒋军杰.选区激光熔化成型医用Ti-6Al-4V合金的组织和性能研究[D].重庆:重庆大学,2015.
[14]Marlo S,Yau T Y,Tuck C.The formation ofα+βmicrostructure in as-fabricated selective laser melting of Ti-6Al-4V[J].Journal of Materials Research,2014,29(17):2028-2035.
[15]韩婕.激光选区熔化成形Ti6Al4V合金的各向异性研究[D].武汉:华中科技大学,2016.
[16]陈静,谭华,张凤英.激光快速成形过程的热行为及其影响[J].中国激光,2007,34(S1):171-174.Chen Jing,Tan Hua,Zhang Fengying,et al.Thermal behavior and its effect on the process of laser rapid forming[J].Chinese Journal of Lasers,2007,34(S1):171-174.
[17]李文艺.钛合金激光快速成形熔池凝固晶粒生长机理研究[D].沈阳:沈阳航空航天大学,2016.
[18]钱远宏,谭华,李静,等.高功率激光立体成形Ti-6Al-4V合金组织研究[J].稀有金属材料与工程,2014,43(9):2162-2166.Qian Yuanhong,Tan Hua,Li Jing,et al.Microstructure characterization of laser solid forming Ti-6Al-4V alloy by high power[J].Rare Metal Materials and Engineering,2014,43(9):2162-2166.
[19]周鑫.激光选区熔化微尺度熔池特性与凝固微观组织[D].北京:清华大学,2016.
[20]GJB 2744A-2007,航空用钛及钛合金锻件规范[S].
[21]赵永庆,洪权,葛鹏.钛及钛合金金相图谱[M].长沙:中南大学出版社,2011.