摘要随着精密机械和电子工业迅猛发展，产品微型化的趋势日益加强，国内外专家和学者对微成形展开了广泛而深入地研究，微成形理论与技术不断创新提升，并走向成熟。镁合金以其重量轻和比强度高等特点而被认为是下一代新型结构材料。塑性变形是结构用金属材料提高产品性能的重要方法之一。本毕业论文工作采用等径角变形和热微挤压组合变形的方式，从而实现提高镁合金微成形性能的目的。利用金相显微镜分析、硬度测试和室温力学性能测试等手段研究了变形条件对AZ31镁合金组织性能的影响。研究结果表明：铸态镁合金AZ31经过等径角变形以后，晶粒细化，塑性得到提高； ECAP态细晶镁合金经过热微挤压以后，抗拉强度有显著的提高，微观组织分布均匀，径向硬度分布受到显著的尺寸效应影响。9210
关键词：AZ31 等径角变形 热微挤压 微观组织 硬度
毕业设计说明书（论文）外文摘要
Title Investigation of Magnesium alloy thermal micro-extrusion process
Abstract
With the rapid development of precision machinery and electronics industries, the trend of products miniaturization increasing, and both domestic and foreign experts and scholars launched a wide-ranging and in-depth study on the micro forming, which promotes the micro-forming theory and technology continuous innovation to improve and mature. The super-light magnesium alloys are considered to be the “New structural materials” for the next generation applications, due to their good ability such as low weight and high specific strength．One of the important methods to improve the mechanical properties of products for metal structure material is plastic deformation．In this paper, equal channel angular pressing (ECAP) and hot-micro-extrusion had been used to alter deformation conditions，and achieved a good micro-formability properties．The relationship between microstructure，mechanical properties and deformation condition was investigated by making use of optical microscopy(OM)，Hardness test ，micro hardness test，and tensile test at temperature．The results indicated that：as-cast AZ31 alloys after ECAP, the ductibility improved along with grains refined；as-ECAPed magnesium alloys with fine grains after hot-micro extrusion, the ultimate tensile strength (UTS) got a higher improvement，and the Microstructure uniformly distributed．The radial distribution of hardness are significantly effected by size effect
Key Words： AZ31 ECAP thermal micro-extrusion Microstructure Hardness
目 次
1 绪论 1
1.1 微成形技术 1
1.1.1 微成形技术的基本概念 1
1.1.2 微成形的理论研究 1
1.1.3 微成形技术种类及工艺 4
1.1.4 微成形技术发展状况 6
1.2 镁及镁合金概述 6
1.2.1 镁及镁合金的主要特点 7
1.2.2 AZ31变形镁合金的研究现状 9
1.2.3 AZ31变形镁合金的微挤压 9
1.2.4 变形镁合金等径角变形研究 11
1.3 论文选题依据、研究内容及试验方法 15
1.3.1 选题依据和意义 15
1.3.2 主要研究内容和试验方法 15
2 材料及实验方法 16
2.1 材料的制备 16
2.2 实验流程 16
2.3 坯料预备 17
2.3.1 均匀化热处理 17
2.3.2 等径角变形 18
2.3.3 线切割制备试样 18 镁合金热微挤压工艺研究+文献综述:http://www.youerw.com/cailiao/lunwen_7845.html