中厚板压下规程优化及模型开发-毕业论文.doc

重庆科技学院 毕业设计（论文） 题目 学 院 冶金与材料工程学院 专业班级 学生姓名 学号 指导教师 职称 评阅教师 职称 2015年月日  由于铝合金具有密度小，比强度高和良好的耐腐蚀性、导电性、导热性，且在低温下能保持良好的机械力学性能等特点，广泛应用于航空航天、汽车和国防等行业。在上述工业领域，其零部件的连接主要靠焊接。铝合金的焊接由于其本身的一些特性，导致焊接问题、困难颇多。 当焊接经过热处理强化的变形铝合金时，焊接接头受热循环的作用，焊接接头的软化成为主要问题。本文在前期铝合金焊接工艺研究的基础上，着重研究热处理对焊接接头性能的影响。 本设计选用10mm的6061铝合金，采用Ф1.2mm的ER4043焊丝进行V型坡口对接MIG焊。通过对焊缝成形的分析，选取最佳的焊接工艺参数；采用优化的工艺施焊，并对焊接试样进行热处理，对热处理后的试样进行力学和金相组织分析。实验结果表明，焊接接头的热影响区存在软化现象，通过530℃×25min固溶处理+160℃×18h时效处理后接头性能得到改善，经历530℃×25min固溶处理+160℃×18h时效处理后焊缝的金相组织主要是α（Al）+β（Mg2Si）β（Mg2Si） 关键词:铝合金 热影响区 软化 热处理 强化相  ABSTRACT As the alloy has a density smaller than the high strength and good corrosion resistance , electrical conductivity , thermal conductivity, and at low temperatures to maintain good mechanical properties and other characteristics, widely used in aerospace , automotive and defense industries. In the industrial sector , which is connected mainly by welding parts . Aluminum welding due to some characteristics of its own , leading to welding problems , many difficulties . When welding aluminum deformation after heat strengthened , the welded joint action of heat cycle, the softening of welded joints become a major problem. Based on the preliminary study of aluminum alloy welding process , the effect of heat treatment focuses on the performance of welded joints . The design uses 6061 aluminum 10mm, using Ф1.2mm the ER4043 welding wire V-groove butt MIG welding. Through the analysis of the weld, select the optimal welding parameters; using optimized process welding, heat treatment and welding samples, the samples after heat treatment the mechanical and microstructure analysis. Experimental results show that the presence of softening the heat affected zone of welded joints by 530℃×25min solution treatment +160℃×18h after aging treatment joint performance improvement, through 530℃×25min solu