Nickel-based superalloy Rene88DT,has been laser-deposited using laser rapid forming (LRF) route.The mechanical properties and microstructure characteristics of LRF Rene88DT at 25℃ and 750℃ were evaluated.The results shows that both strength and ductility of LRF Rene88DT can be improved significantly by the integration of optimized heat treatment (solution treatment (1160℃,2h/AC) + aging (760℃,8h/AC)) and the HIP treatment(1160℃,2h/200MPa).25℃ tensile properties is comparable to that of the Powder Metallurgy standard.The 750℃ tensile strength and ductility are also comparable to those of the Powder Metallurgy standard,but the yield strength is still a little lower at 750℃.As compared with the as-deposited state,g' precipitates of LRF Rene88DT are evolved gradually to be spherical in shape and uniformly distribute in the g matrix after optimized heat treatment and HIP treatment.Fracture surface shows that crack initiates at the edge for all the samples of LRF Rene88DT after tensile deformation.The deformation is found to be homogeneous in the whole sample.Necking phenomenon exists near the fracture surface,which corresponds with the superior strength and ductility of LRF Rene88DT.
Zhao Xiaoming1,2,Gong Shuili1,Lin Xin2,Chen Jing 2,Huang Weidong21Science and Technology on Power Beam Processes Laboratory,AVIC Beijing Aeronautical Manufacturing Technology Research In-stitute,Beijing 100024,China2State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China
