超细晶6061铝合金的搅拌摩擦制备和性能  

Prepration and Mechanical Properties of Ultrafine-grained 6061 Al-alloy by Friction Stir Process

作　　者：王贝贝 刘沿东 薛鹏[2] 倪丁瑞[2] 肖伯律[2] 马宗义[2] WANG Beibei;LIU Yandong;XUE Peng;NI Dingrui;XIAO Bolv;MA Zongyi(School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]东北大学材料科学与工程学院,沈阳110819 [2]中国科学院金属研究所师昌绪先进材料创新中心,沈阳110016

出　　处：《材料研究学报》2021年第5期321-329,共9页Chinese Journal of Materials Research

基　　金：国家自然科学基金(52071317,U1760201);中国科学院青年创新促进会基金(2017236)。

摘　　要：对6061铝合金进行常规空冷和强制水冷的搅拌摩擦加工(FSP)并研究其微观组织和力学性能,结果表明:FSP 6061铝合金的加工区均为细小等轴的超细晶组织,晶内位错密度较低、高角晶界的比例均高于70%;采用强制水冷,可将FSP 6061铝合金的平均晶粒尺寸细化到200 nm。FSP 6061铝合金中的析出相主要为球状或短棒状,采用强制水冷使析出相的长大受到明显抑制并使部分固溶元素不能及时析出,使析出相的尺寸与间距明显减小。与常规空冷相比,在强制水冷条件下FSP制备的6061铝合金具有更高的细晶强化和沉淀强化效果,其抗拉强度高达505 MPa,比峰时效态6061铝合金母材提高了55%。6061 Al-alloy plates were prepared by friction stir process(FSP) with conventional air cooling and additional water cooling, and the microstructure and mechanical properties of the FSP 6061 Al-alloys were investigated. Results show that the processed zone was characterized as equiaxed uniform ultrafine-grained(UFG) microstructure with low dislocation density and high fraction of high angle grain boundaries(>70%), and the average grain size was refined to 200 nm in the condition of additional water cooling. Spherical and rod-like precipitates were observed in the FSP 6061 Al-alloy. The applying of additional water cooling suppressed the growth of precipitates, led to the solid solution of some elements in the matrix, and reduction of precipitate size and space. The FSP 6061 Al-alloy prepared with additional water cooling exhibited higher effect of grain boundary strengthening and precipitation strengthening, resulting in a high ultimate tensile strength of 505 MPa, which was 55% higher than that of the 6061 Al-alloy of peak aging state.

关 键 词：金属材料 超细晶材料 搅拌摩擦加工 力学性能 强化机制 

分 类 号：TG146[一般工业技术—材料科学与工程]