【摘要】 采用扫描电镜原位拉伸方法,跟踪观察了人工植入Al2O3夹杂物的镍基粉末高温合 金P／MRene95中夹杂物导致裂纹萌生、扩展乃至断裂的过程.结果表明,在单轴拉伸载荷下, 裂纹首先萌生于脆性非金属夹杂物Al2O3处,大于一定尺寸的夹杂物,还会使该裂纹扩展成为 导致合金断裂的主裂纹,从而大大降低合金的屈服强度及断裂强度.更多还原

【Abstract】 In situ tensile tests with special designed SEM were conducted to trace the whole process of crack initiation and propagation till to fracture of Al2O3 seeded P/M Rene 95 Ni-base superalloy. The experimental results show that a non-metallic inclusion can induce crack initiation. When the inclusion size is larger than a certain critical size, the crack can propagate to be the main crack inducing the specimen to fracture. Consequentially, both the yield strength and the tensile strength of the specimen are remarkably decreased.更多还原