摘要
选区激光熔化金属材料普遍存在晶粒不规则和热应力高等问题,而热处理可以使组织成分趋于均匀并降低残余应力。因此,研究3种不同热处理工艺对选区激光熔化FeSiB/316L不锈钢的微观结构和力学性能的影响。研究发现经400℃热处理2 h后,内部晶粒细化,导致位错密度上升,其抗拉强度提高但延伸率变化不大。然而,经700℃热处理2 h后,晶粒尺寸变大,导致位错密度下降,其抗拉强度下降,但延伸率相对于未热处理FeSiB/316L复合试样提升了28%。经1050℃热处理2 h后,熔池边界和柱状晶等结构消失,使得变形阻力下降,显微硬度和抗拉强度下降42%,延伸率提升了2.5倍。
Selective laser melting(SLM)of metal materials often results in irregular grains structures and high thermal stress,issues that can be addressed through heat treatment to achieve a more uniform microstructure and reduced residual stress.Therefore,the effects of three different heat treatment processes on the microstructure and mechanical properties of selective laser melting FeSiB/316L stainless steel were studied in this paper.It was found that after heat treatment at 400℃for 2h,the internal grains were refined,resulting in an increase in dislocation density.Its tensile strength increases and the elongation did not change much.However,after heat treatment at 700℃for 2 h,the grain size becomes larger,resulting in a decrease in dislocation density.The tensile strength decreased,but the elongation increased by 28%compared with the unheated FeSiB/316L composite sample.After heat treatment at 1050℃for 2 h,the structure of molten pool boundary and columnar crystal disappeared,which reduced the deformation resistance.The microhardness and tensile strength decreased by 42%,and the elongation increased by 2.5 times.
作者
余金桂
肖继斌
章桥新
Yu Jingui;Xiao Jibin;Zhang Qiaoxin(School of Mechanical and Electrical Engineering,Wuhan University of Technology,Wuhan 430070,Hubei,China)
出处
《应用激光》
CSCD
北大核心
2024年第9期19-27,共9页
Applied Laser
