固溶时间对6061铝合金厚不均匀性及残余应力的影响.docVIP

不同时间固溶后6061铝合金李美春邓运来唐建国万里张新明(中南大学材料科学与工程学院，长沙 410083；有色金属材料科学与工程教育部重点实验室，长沙 410012）摘要：结果表明：关键词：铝合金；固溶；；织构 中图分类号： TG146.4 文章编号：icrostructure and properties of 6061 aluminum alloy thick plate and its residual stress with different solution treat time LI Mei-chun, DENG Yun-lai, TANG Jian-guo*, WAN Li, ZHANG Xin-ming (School of Materials Science and Engineering, Central South University, Changsha 410083, China; Key Laboratory of Nonferrous Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410012, China) Abstract：mechanical properties along the thickness and residual stress of 6061 aluminum alloy plate was investigated by hardness, tensile test and hole drilling respectively. The microstructure and crystallographic texture of 6061 aluminum alloy plate was investigated by optical microscopy, transmission electron microscopy and X-ray diffraction. Then with the Schmidt factor based on single slip crystal plasticity, the influence of crystallographic texture on mechanical properties and residual stress distribution was analyzed. The results showed that the microstructure, orientation density and mechanical properties difference between surface and center layer and residual stress decrease with increasing solution heat treatment time 2h to 4h. The difference of residual stress of the plate is ascribed to evolution of crystallographic texture, which can be explained with the weighted mean value of Schmidt Factor. Key words: aluminum alloy thick plate; solution treatment time; residual stress; texture 0 引言 6061铝合金是可热处理强化的中高强度铝合金，具有良好的机械加工性能和抗腐蚀能力，广泛应用于要求具有一定强度和高抗蚀能力的各种结构[2-3]，残余应力的存在会极大地影响板材的加工性能、疲劳寿命以及耐蚀性能等[4]。目前，消减残余应力的主要方法有机械法和热处理方法[5-7]，机械法在工程实际应用中，需要较大的成本。对于6061铝合金，研究合适的热处理工艺在提高其力学性能的同时降低残余应力具有重要的理论和实际意义。 目前国内外对铝合金板材的变形过程、热处理过程微组织及性能之间的关系做了大量的研究[8-10][5, 11]，但大部分文献对厚板残余应力的研究一般从宏观角度出发，很少有人研究材料显微组织与淬火残余应力之间的关系。研究表明铝镁硅合金在固溶热处理过程中会发生显著的再结晶[12]，再结晶过程中织构有可能发生改变，而织构的改变意味着材料的性能将发生改变。为此，作者以22mm厚的6061铝合金热轧厚板为研究对象，研究了时间固溶板材，Schmidt因子，从