摘要
为了优化快速成形零件组织和力学性能,利用脉冲等离子焊接快速成形工艺制备了Inconel625合金薄壁零件.采用扫描电镜、透射电镜研究了固溶温度对成形零件组织的影响规律.结果表明:沉积态组织以胞状枝晶为主,具有较强生长取向性的外延枝晶组织特征,同时,在枝晶间隙析出大量的Laves相和少量的MC碳化物.经过720℃/1 h的固溶处理,金相组织没有发生明显变化,但导致γ″(Ni3Nb)相的析出.经850℃固溶处理,组织中的Laves相部分被溶解,生成了针状δ相.当固溶温度升高到980℃,Laves相几乎完全溶解,δ相发生了部分回溶.而经过1 080℃固溶处理,消除了元素的偏析和Laves相,但再结晶导致晶粒严重长大.980℃是最佳的固溶处理温度.
Pulsed PAW rapid prototyping technology was used for fabricating Inconel625 alloy thin-wall component to optimize the microstructure and mechanical property.The effect of solution heat treatment temperature on the microstructure of Inconel625 alloy component was investigated by means of SEM and TEM.The results revealed that the as-deposited structure exhibited homogenous cellular dendrite structure,which grew epitaxially along the deposition direction.Moreover,some intermetallic phases including Laves phase and MC carbides were precipitated in the interdendritic region.Little changed during solution heat treatment at 720 ℃ for 1 h except the precipitation of hardening phase γ″（Ni3Nb）,at 850 ℃,the dissolution of Laves phase and the precipitation of acicular δ phase were resulted in,and at 980 ℃,more Laves particles and δ phase were dissolved into γ matrix.However,at 1 080 ℃,Laves particles were dissolved into the matrix completely and the Nb segregation was relieved,and the mechanical properties decreased severely as a result of the grain growth coarsening.It was concluded that 980 ℃was the best temperature of solution heat treatment.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2013年第2期14-19,共6页
Materials Science and Technology
基金
国家重点基础研究发展规划资助项目(2011CB013403)
国家科技支撑项目(2011BAF11B07
2011BAC10B05)
国防科技重点实验室基金资助项目(9140c850205120c8501)
