铸件尺寸对镍基单晶高温合金力学性能的影响  

Influence of Casting Size on Mechanical Properties of Ni-base Single Crystal Superalloy

作　　者：史振学[1] 韩梅[1] 刘世忠[1] 李嘉荣[1] 

机构地区：[1]北京航空材料研究院先进高温结构材料重点实验室,北京100095

出　　处：《热加工工艺》2012年第17期22-24,27,共4页Hot Working Technology

摘　　要：浇注了两种不同尺寸的镍基单晶高温合金铸件试样,研究了试样尺寸对显微组织的影响,利用扫描电镜分析了合金的断口形貌和断裂机制。结果表明,浇注试样尺寸增大,合金的枝晶间距和热处理后γ′相的尺寸增大。合金在760、980℃下的拉伸性能以及980℃和250MPa条件下的持久性能均有不同程度的降低。合金760℃的拉伸断裂为类解理断裂,980℃的拉伸断裂以及980℃和250MPa条件下的应力断裂都为韧窝断裂。The Ni-base single crystal superalloy samples with two different sizes were cast. The effects of sample size on the microstructure were investigated. The fracture surface and fracture mechanism of the alloy were examined by SEM. The results show that with increase of casting sample size, the dendrite arm spacing and the size of ＂/＇ phase particles after heat treatment increase. The tensile properties of the alloy at 760C or at 980C slightly reduce; the stress rupture properties of the alloy at 980C/250MPa slightly reduce. The tensile fracture mechanism of the alloy at 760C show similar cleavage fracture. The tensile fracture mechanism at 980~C and stress rupture mechanism at 980C/250MPa all show dimole fracture.

关 键 词：单晶高温合金 试样尺寸 性能 断裂机制 

分 类 号：TG132.3[一般工业技术—材料科学与工程]