喷射沉积Ni3Al-Mo合金的位错结构分析和断裂特性(英文)  

Dislocation Structure and Fracture Characteristics of Spray Deposited Ni_3Al-Mo Intermetallic Compound Alloy (IC6)

作　　者：米国发[1] 浮红霞[1] 刘彦磊[1] 田世藩[2] 

机构地区：[1]河南理工大学,河南焦作454001 [2]北京航空材料研究院,北京100095

出　　处：《稀有金属材料与工程》2008年第7期1144-1148,共5页Rare Metal Materials and Engineering

基　　金：Funded by the Innovation Fund for Outstanding Scholar of Henan Province (0621000700)

摘　　要：利用多功能雾化沉积装置,制备了 Ni3Al-Mo 高温合金。拉伸性能测试表明:喷射沉积 Ni3Al-Mo 合金的屈服强度有明显的"R"特性,即喷射沉积合金的屈服强度随着温度的增加而增加,在 760 ℃时达到最大值;随着温度的继续增加,屈服强度会逐渐降低。利用 TEM 对位错结构分析,阐明了合金屈服强度与微观结构之间的关系。研究结果表明,试验合金所具有的屈服强度随温度的变化规律主要是由不同温度下γ′及γ相内的位错缠结状况、位错对的形态及数量和六面体滑移系的开动程度决定的。裂纹的 TEM 分析表明,随着变形应力的增加,裂纹在晶界部位产生,然后迅速扩展,而且在不同的晶面内存在一些不同的滑移带。喷射沉积合金在室温、中温及高温下裂纹严格沿八面体滑移系(111)面开裂。A Ni3Al-Mo intermetallic compound alloy （IC6） was prepared by using the multifunctional spray atomization and deposition plant. Tensile properties tests indicate that the spray deposited Ni3Al-Mo alloy possesses ＂R＂ characteristics in the yield strength, that is, the yield strength of the spray deposited IC6 increases with increasing of temperature and it reaches maximum around 760℃. After that, they decrease with increasing of temperature. Analyses of dislocation structure by TEM reveal the relationship between the microstructure and yield strength. The results show that the change of the yield strength of the alloy with temperature is associated with the condition of dislocation winding, pattern and quantity of the dislocation pairs and starting degree of the hexahedron slip system inside γ＇ and γ phases. The analysis of cracking by stereographic projection shows that with the increase of deformation stress the cracks form at grain boundaries and then quickly propagate, and some different slip bands exist in little planar zones; no matter at room temperature, middle temperature or high temperature, cracks craze along （111） plane octahedron slip.

关 键 词：Ni3Al-Mo合金 拉伸性能 位错结构 断裂特性 

分 类 号：TG111[金属学及工艺—物理冶金]