选区激光熔化GH3536合金的热处理工艺

采用OM、SEM和力学性能测试等分析研究了不同热处理工艺对选区激光熔化成形GH3536合金组织及力学性能的影响规律。结果表明,随着固溶温度越高,晶粒尺寸越大,且抗拉强度在高温条件下逐渐增加而室温条件则下降。当固溶温度达到1120 ℃时,室温条件下横向试棒与纵向试棒的抗拉强度分别达到816和731 MPa;900 ℃高温条件下则分别达到189和204 MPa。800 ℃时效处理后合金基体组织析出细小碳化物,产生第二相强化作用,强度得以提升。随着时效时间的增加,碳化物变的密集,但晶粒尺寸几乎没有发生变化,表现为室温抗拉强度与断后伸长率得到提升。当时效时间达到20 h时,室温条件下横向试棒与纵向试棒的抗拉强度分别达到832和747 MPa;900 ℃高温条件下横向试棒与纵向试棒的断后伸长率分别达到8.5%和21.5%。最后得出选区激光熔化成形GH3536合金最优的热处理工艺为:固溶(1120 ℃×1 h)+时效(800 ℃×20 h)。

Heat treatment of selective laser melting GH3536 alloy

Effect of different heat treatment processes on the microstructure and mechanical properties of selected lasive melting GH3536 alloy was studied by means of OM,SEM,and mechanical properties tests.The results show that,with the solution treatment temperature increasing,the grain size increases,the tensile strength increases gradually at high temperature and decreases at room temperature.When the solution temperature reaches 1120℃,the tensile strengths of transverse and longitudinal specimens at room temperature can reach 816 and 731 MPa,respectively.While that of transverse and longitudinal test bars reach 189 and 204 MPa at 900℃,respectively.After aging at 800℃,the alloy matrix can precipitate fine carbides,which has an effect on second phase strengthening,and so that the strength can increase.With the increase of aging time,the carbides become denser,but the grain size changes a little,which leads to the increase of both tensile strength and percentage elongation after fracture at room temperature.When the aging time reaches 20 h,tensile strengths of the transversal and longitudinal test bars at room temperature reach 832 and 747 MPa,respectively.The percentage elongations after fracture of transversal and longitudinal test bars at 900℃reaches 8.5%and 21.5%,respectively.Finally,the optimal heat treatment process for the selective laser melting GH3536 alloy is solution treated at 1120℃for 1 h,and then aged at 800℃for 20 h.