复合SPD制备超细晶6061铝合金的组织及性能  

Microstructure and Mechanical Properties of Ultra-fine Grained Al Alloy Processed by Combined SPD Technology

作　　者：刘兆华[1] 王晓琪[1] 陈亮伟[1] 起华荣[1] 史庆南[1] 

机构地区：[1]昆明理工大学材料科学与工程学院,昆明650093

出　　处：《材料工程》2014年第11期62-66,共5页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目(51064016)

摘　　要：采用反复镦压和等径角挤压相结合的复合挤压技术,在室温对退火态的6061铝合金进行4道次变形,获得等轴的超细晶铝合金。借助于透射电镜对变形过程的微观组织演变过程进行观察,提出了复合挤压过程中晶粒细化的过程。对不同实验状态的试样进行了硬度和拉伸实验,试样三个垂直面的硬度值增加了1倍,抗拉强度由165 MPa增加到402.7 MPa,但伸长率由26.8%下降到9.7%,复合挤压比等径角挤压对试样的力学性能影响更剧烈。The annealed 6061 Al alloy was subjected to four pass combined extrusion deformation at room temperature using the procedure of cyclic channel die compression and equal channel angular pressing,equixed ultra-fine grained(UFG)6061Al alloy was successfully obtained.The evolution of the microstructure during deformation was investigated by means of transmission electron microscopy analysis.The grain refinement was discussed during combined extrusion deformation.The hardness and tensile tests were conducted,respectively.The average hardness value doubled on the three orthogonal planes.The tensile strength increases from 165 MPa to 402.7 MPa after four pass,meanwhile the elongation reduces from 26.8% to 9.7%.These results demonstrate the influence of the combined extrusion deformation on the mechanical properties of the samples is more severe in comparison to equal channel angular pressing.

关 键 词：反复镦压 等径角挤压 超细晶 6061铝合金 剧烈塑形变形 

分 类 号：TG146.21[一般工业技术—材料科学与工程]