摘要有研究表明,随着微成形件尺寸的不断减小,单个晶粒对坯料的机械性能和变形行为的影响开始成为主导,尺寸效应成为微成形技术进一步发展的关键突破口。为研究AZ31镁合金室温力学性能的尺寸效应,本课题主要通过采用热挤压和ECAP制备处理AZ31镁合金,利用电子万能材料试验机对厚度不同的AZ31镁合金工字型试样进行单向拉伸实验。实验结果表明:AZ31镁合金热挤压和ECAP后的力学性能存在明显的尺寸效应,即随着工字型板料试样厚度的减小,材料的延伸率、抗拉强度和屈服强度可能升高也可能降低,它们与晶体取向、挤压温度、挤压道次等因素有关。
关键词: 微成形; AZ31镁合金; 尺寸效应; 力学性能; 热挤压; ECAP;8530
毕业设计说明书(论文)外文摘要
Title: Size Effects of AZ31 Magnesium Alloy on Room-temperature Mechanical Properties
Abstract
Research has shown that, with the micro-forming size decreasing, the impacts of a single grain to the mechanical properties and deformation behavior of billet start to become dominant,and size effects has become the key to micro forming. To study AZ31 magnesium alloy size effect of mechanical properties at room temperature, this topic is mainly using hot extrusion and ECAP technology to deal with AZ31 magnesium alloy, and the electronic almighty material experiment machine is exploited to do the uniaxial tensile experiments with different thickness of AZ31 magnesium alloy font specimens. Experimental results show that, the mechanical properties of AZ31 magnesium alloy have obvious size effects after hot extrusion and ECAP. That is to say, the elongation rate, tensile strength and yield strength of the material may increase or decrease with the thickness of the font sample decreasing. And we can find that they depend on the crystal orientation, extrusion temperature and extrusion ratio.
Keywords: micro forming; AZ31 magnesium alloy; size effect; Mechanical properties; Hot extrusion; ECAP;