Microstructural and mechanical properties of friction stir welded Cu–30Zn brass alloy at various feed speeds: Influence of stir bands
Microstructural and mechanical properties of friction stir welded Cu–30Zn brass alloy at various feed speeds: Influence of stir bands
复制标题
DOI：
10.1016/j.matdes.2011.01.015
复制
发表时间：
2011-05
影响因子：
8.4
通讯作者：
M. Moghaddam;R. Parvizi;M. Haddad-Sabzevar;A. Davoodi
中科院分区：
文献类型：
--
作者：
M. Moghaddam;R. Parvizi;M. Haddad-Sabzevar;A. Davoodi
在这项研究中，研究了不同的进给速度对搅拌摩擦焊Cu-30Zn黄铜合金显微组织和机械性能的影响。转速固定为 950rpm，进给速度在 190-375mm/min 范围内变化。微观结构的检查表明，搅拌区有非常细的晶粒，其中有一些变形的晶粒，而热机械影响区和基体金属中有一些较粗的晶粒。确定了搅拌区区域中独特的变形模式，即“搅拌带”，并且其密度随着进给速度的增加而增加。结果表明，晶粒尺寸分布与进给速度无关，并且硬度值随着进给速度的增加而降低。进给速度的增加导致屈服强度和极限拉伸强度略有改善，这与作为强化结构的搅拌带的连续弹簧状形态有关。然而，延展性从 57% 大幅降低至 27%。此外，据观察，在拉伸试验期间，断裂裂纹恰好起源于搅拌带附近。
In this study, the effect of various feed speeds on microstructure and mechanical properties of friction stir welded Cu–30Zn brass alloy is investigated. Rotation speed was fixed at 950rpm and feed speed varied in the range of 190–375mm/min. Examination of the microstructure showed very fine grains with some deformed grains in the stirred zone and some coarser grains in the thermo-mechanically affected zone and base metal. A unique deformation pattern, namely “stir band” in the stirred zone region was identified and its density increased by increase in feed speed. Results showed that the grain size profile was independent of feed speed and the hardness values decreased by increase in feed speed. Increase in feed speed led to a slight improvement of yield strength and ultimate tensile strength, associated to continuous spring-like morphology of stir bands acting as a strengthening structure. However, ductility reduces considerably from 57 to 27%. Moreover, it is observed that during tensile test, fracture cracks originate exactly adjacent to the stir bands.