【摘要】 研究了铝含量对一种镍基单晶合金铸态和热处理态显微组织的影响,测试了单晶合金的高温持久性能,利用金相显微镜、SEM、TEM、XRD等考察了持久断裂试样的微观形貌。结果表明,单晶合金的铸态组织由粗大的γ’、细小的γ’和γ组成,随Al含量的增加,粗大的γ’相数量增多、尺寸增大。固溶处理不能使粗大的γ’完全固溶,持久断裂裂纹主要在粗大的γ’/γ界面产生,并沿γ’/γ界面扩展,严重损伤合金的高温持久性能。更多还原

【Abstract】 The effects of Al content on the microstructure of as-cast and heat treatment specimens were investigated.The stress rupture of the alloy at high temperature was measured and the microstructure of stress rupture specimens was observed by SEM,EDS,and XRD.The results show that the as-cast microstructure of the alloy is composed of coarsening γ’,fine γ’ and γ.With the increase of Al content,the more coarsening γ’ appears in the alloy and cannot be dissolved into γ matrix completely during solid solution heat-treating.The observation of microstructure indicates that the micro-cracks occur mainly at the coarsening γ’/γ interface during stress rupturing measuring and extends along γ’/γ interface,all these are harmful to the high temperature properties of the alloy.更多还原