Influence of hot isostatic pressing on microstructure,properties and deformability of selective laser melting TC4 alloy  

作　　者：Tai-qi Yan Bing-qing Chen Xia Ji Shao-qing Guo 

机构地区：[1]3D Printing Research and Engineering Technology Center,Beijing Institute of Aeronautical Materials,Beijing 100095,China [2]Falcon Fast Manufacturing Technology Co.,Ltd.,Wuxi 214145,Jiangsu,China

出　　处：《China Foundry》2021年第4期389-396,共8页中国铸造（英文版）

摘　　要：The influence of different hot isostatic pressing regimes on microstructure,phase constitution,microhardness,tensile properties and deformability of TC4 alloy fabricated by selective laser melting(SLM)technology was studied.The results show that the microstructure of SLM TC4 alloy is composed of acicular martensiteα’phase,and the sample exhibits high microhardness and strength,but low plasticity.After hot isostatic pressing,acicular martensiteα’phase transforms intoα+βphase,and with the increase of hot isostatic pressing temperature and duration,αphase with coarse lath is gradually refined,and the proportion ofαphase is gradually reduced.Because of the change of phase constitution in SLM TC4 alloy after hot isostatic pressing,the grain refinement strengthening is weakened,the density of dislocation is reduced,so that both microhardness and tensile strength are decreased by around 20%,the elongation is increased by more than about 70%,even over 100%,compared with as-deposited TC4 alloy.When the hot isostatic pressing regime is 940°C/3 h/150 MPa,the tensile strength and the elongation achieve optimal match,which are about890 MPa and around 14.0%in both directions.The fracture mechanism of alloy after 940 oC/3 h/150 MPa HIP is dultile fracture.Hot isostatic pressing causes concave deformation of SLM TC4 alloy thin-walled frames,and the deformation degree increases with the increase of temperature.

关 键 词：selective laser melting TC4 alloy hot isostatic pressing MICROSTRUCTURE mechanical properties DEFORMABILITY 

分 类 号：TG146.23[一般工业技术—材料科学与工程]