Effect of Heat Treatment on Microstructure and Properties of GH4061 Alloy by Selective Laser Melting
The study investigated the impact of heat treatment on the microstructure and tensile properties of GH4061 alloys fabricated by selective laser melting.Findings demonstrated that the as-built columnar grains experienced epitaxial growth spanning multiple molten pools,resulting in the formation of cellular substructures.Following heat treatment,as the solid solution temperature increased,there was a gradual shift in grain orientation towards the(101)and(111)crystal planes.The Laves phase transitioned from elongated chains to granular forms and dissolved at approximately 1060℃.The δ phases that precipitated at grain boundaries transformed from coarse bulk structures to disc-shaped,and eventually to short rod-shaped configurations.The average sizes of γ′ and γ″ phases are 23.53 nm,24.43 nm,25.34 nm and 25.66 nm at solution temperature of 980℃,1020℃,1060℃,1100℃,respectively.The mechanical properties of the alloys after heat treatment show significant improvement at both room temperature and 650℃.Specifically,the tensile strengths at room temperature and 650℃for the sample subjected to the 980℃solid solution aging heat treatment are 1342 MPa and 1120 MPa,respectively.As the solid solution temperature increases,the room temperature tensile strength at 1020℃,1060℃and 1100℃decreases by approximately 6.4%,8.3%,and 10%than that at 980℃,respectively.At 650℃,the tensile strength at 1020℃,1060℃and 1100℃decreases by approximately 7.9%,8.8%,and 11%than that at 980℃,respectively,while the plasticity increases.
NETL
NSTL
万方数据
