摘要
通过冷变形拉拔结合中间热处理制备了纤维相增强的Cu12%Ag(质量分数)合金,研究了变形过程对组织形态和力学性能的影响。随着变形程度的增加,不连续分布的原始共晶体演变成细密的纤维束结构,合金强度和硬度升高。在一定变形程度范围内或当共晶纤维束间距约大于150nm时,抗拉强度随共晶纤维束间距的变化类似于HallPetch关系,强化效应与位错塞积机制有关;当拉拔变形超过一定程度或共晶纤维束间距小于约150nm后,合金强化速率降低并偏离HallPecth关系,强化效应可认为与界面障碍机制有关。
Cu-12%Ag filamentary composite was prepared by cold drawing and intermediate heat treatments. The evolution of filamentary microstructure and mechanical properties were investigated for the alloy at different draw ratio. With the increasing draw ratio, the as-cast eutectic colonies with a discontinuous distribution develop into fine fibrous bundles to result in the increase of the strength and hardness. As the draw ratio is in a certain strain range or the spacing of eutectic fibrous bundles greater than is 150nm, the ultimate tensile strength dependent on the spacing of eutectic fibrous bundles is similar to the Hall-Petch relationship. The mechanism of pile-up of dislocation can be suggested to be responsible for the strengthening benefit. As the draw ratio is over a certain degree or the spacing of eutectic fibrous bundles is less than 150nm, the strength increase becomes slow and deviates from the Hall-Petch relationship. The mechanism of athermal obstacles at the interfaces can be suggested to be responsible for the strengthening benefit.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2005年第5期751-756,共6页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(50371076)
高等学校博士学科点专项科研基金资助项目(20020335014)
关键词
CU-AG合金
纤维组织
强度
硬度
应变率
Cu-Ag alloy
filamentary microstructure
strength
hardness
draw ratio
