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研究了固溶+双级时效处理对激光选区熔化(SLM)工艺制备的Inconel 718高温合金微观组织形态和析出相的影响.结果表明,SLM沉积态合金为椭圆状晶组织,其由细小柱状晶组成.沉积态合金经固溶处理后转变成等轴细晶组织,且随固溶温度升高,晶粒尺寸增大.经固溶+双级时效处理后,合金会在晶界和晶内析出多种析出相,在940～1 020℃固溶过程中晶界析出短棒状δ相(Ni3 Nb),在620～720℃时效过程中晶内析出针状δ、圆盘状γ″(Ni3Nb)和黑点状γ′相(Ni3 Al,Ti).“,”The effects of solid solution-+-two-step aging on the morphology and precipitates in the Inconel 718 superalloy by selective laser melting(SLM) were investigated.It is found that,the microstructure of SLM as-deposited alloy exhibits elliptical grain,which consists of the tiny columnar grain.After solid solution treatment,the columnar grains in as-deposited alloy are transformed into the equiaxed grain.The grain size is increased with solution temperature increase.The various precipitates can be precipitated at the grain boundary and in the grain after solution +-two-step aging.Short rod-like δ phases can be observed at the grain boundary during 940～ 1 020 ℃ solution,while needle-like δ,discshaped γ" and dark spot γ′ phases can be observed in grain with aging at 620～720 ℃.