铸态铅黄铜准超塑性变形及其机理的研究  

Study on quasi-superplasticity deformation behaviour and mechanism of as-cast leaded brass

作　　者：杨永顺[1] 董文杰[1] 文九巴[1] 

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471003

出　　处：《材料热处理学报》2007年第6期37-39,共3页Transactions of Materials and Heat Treatment

基　　金：河南省科技攻关项目(0624260035)

摘　　要：通过恒速度拉伸试验，研究了铸态铅黄铜的准超塑性变形行为及其机理。结果表明：在620～680℃，初始应变速率1×10^-4～1×10^-1s^-1范围内材料表现出良好的超塑性。最佳条件为660℃，保温25min后，以初始应变速率1×10^-2s^-1拉伸，SEM断口扫描和TEN透射照片显示：试样为典型的韧窝断裂；变形初期产生大量位错，随着变形逐渐形成亚晶界，进而演变为小角度和大角度晶界，整个过程是由位错的产生及再结晶来实现的。The quasi-superplasticity deformation behaviour and mechanism of as-cast leaded brass was investigated through constant velocity tensile test. The results indicate that as-cast leaded brass presents certain superplasticity at 620 - 680 ℃ and 1×10^-4 - 1×10^-1s^-1. The optimum parameters for superplasticity deformation of leaded brass is heating the alloy at 660℃ for 25min and then tension with an initial strain rate 1×10^-2s^-1. SEM and TEM observation shows that dimple fracture prevails, and great numbers of dislocations generate during the initial deformation, then develop into subgrain boundaries which evolve into low and high angle grain boundaries. The whole process is achieved by generation of dislocation and recrystallization.

关 键 词：铸态铅黄铜 准超塑性 机理 位错 再结晶 

分 类 号：TG146.1[一般工业技术—材料科学与工程] TG301[金属学及工艺—金属材料]