摘要
采用硬度与电导率测试、拉伸试验、晶间腐蚀和剥落腐蚀试验以及X射线衍射(XRD)、扫描电镜(SEM)、电子背散射衍射(EBSD)分析等方法研究预变形对Al-12.45Zn-3.56Mg-1.12Cu-0.21Zr-0.0553Sr铝合金挤压材组织与性能的影响。结果表明:该合金在(121℃,24 h)时效制度下,预变形处理能有效引入位错,位错密度从0.197×10^(-14)m^(-2)提高到1.156×10^(-14) m^(-2);同时,由于位错对强度的贡献高达58.7 MPa。根据EBSD分析,经预变形处理后,合金的低角度晶界所占比例为66.2%,比未经预变形处理的合金提高12.6%,平均晶界角度值降低3.894°,平均晶粒尺寸增长6.396mm。预变形能够明显提高合金的抗晶间腐蚀性能(最大晶间腐蚀深度由222.1mm降低至165mm),对剥落腐蚀性能的影响不明显。
The effects of pre-deformation on microstructure and properties of Al-12.45Zn-3.56Mg-1.12Cu-0.21Zr-0.0553Sr ultra-high strength aluminum alloy extrusion materials were studied by means of micro-hardness tester and electrical conductivity test, tensile test, intergranular and exfoliation corrosion experiment, X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron back-scattered diffraction (EBSD) analysis. The results show that in the aging system at 121℃ for 24 h, the pre-deformation can effectively introduce dislocations, the dislocation density increases from 0.197×10?14m?2to 1.156×10?14 m?2, and the strength reaches up to 58.7 MPa because of the dislocation contribution. Based on EBSD analysis, after pre-deformation treatment, the low angle grain boundary proportion (66.2%) of the pre-deformation alloy increases by 12.6% than that of the underformed alloy, the mean misorientation value reduces 3.894°, and the average grain size increasesby 6.396 μm. The pre-deformation treatment can significantly improve the intergranular corrosion resistance properties (the maximum intergranular corrosion depth reducing from 222.1 μm to 165 μm), but little improvement on exfoliation corrosion performance.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2016年第3期507-515,共9页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(51074079)
江苏省工业科技支撑计划项目(BE2008118)
江苏省高校研究生科研创新计划项目(CXLX110563)
江苏大学"拔尖人才培养工程"基金资助项目(1211110001)~~
关键词
超高强铝合金
挤压材
预变形
显微组织
性能
ultra-high strength aluminum alloy
extrusion materials
pre-deformation
microstructure
property
