半固态粉末压缩Mg-6Zn合金过程数值模拟  

Numerical simulation of semi-solid powder compression process of Mg-6Zn alloy

作　　者：任俊 罗霞 蔡晓文 范舟[1] 黄本生[1] REN Jun;LUO Xia;CAI Xiaowen;FAN Zhou;HUANG Bensheng(School of New Energy and Materials,Southwest Petroleum University,Chengdu 610500,China;Chengdu Institute of Advanced Metal Materials Industrial Technology,Chengdu 610305,China)

机构地区：[1]西南石油大学新能源与材料学院,四川成都610500 [2]成都先进金属材料产业技术研究院股份有限公司,四川成都610305

出　　处：《粉末冶金工业》2022年第3期49-56,共8页Powder Metallurgy Industry

基　　金：国家自然科学基金资助项目(51704255);四川省科技厅国际合作项目(2020YFH0151)。

摘　　要：基于半固态热模拟压缩实验推导出的粉体材料本构方程,运用MSC.Marc软件对半固态粉末成形医用Mg-6Zn合金的压缩过程进行了数值模拟,分析了致密化过程中相对密度、粉末位移变化情况,并对模型的可靠性进行了实验验证,探究了温度对半固态粉末成形的影响规律。结果表明:液相分数低于10%时,成形温度对相对密度的影响不大,且随着压缩的进行,相对密度逐渐增加并趋于稳定;半固态粉末成形应力集中在圆柱压坯边缘两端处,应力最小值出现在圆柱坯的中心两端和边缘处“鼓肚”区;该模型在低液相分数下具有良好的可靠性,而液相分数较高时误差很大,液相是产生误差的根本原因。Magnesium alloy has become the most promising bone implant and vascular stent materials due to its good biocompatibility, matched elastic modulus and biodegradability. However, the poor degradation performance and unclear metabolic mechanism of degradation products limit its further application. In order to meet the degradation adaptation of magnesium alloy, a novel powder metallurgy named semi-solid powder moulding was adopted to prepare the medical Mg-6Zn alloy. Semi-solid powder moulding is a near-net shape forming technique, which combines powder forming and semi-solid forming with one step. It has great advantages to prepare the alloys and its composites with low melting point and wide solidification range. In order to optimize the forming process and get excellent performance of Mg alloys, it is necessary to simulate the forming process in the preparation of medical Mg-6Zn alloy. As this technique simultaneously involves in deformation, solidification and densification, it has many difficulties in the simulation of forming process. This study gives a clue for the simulation of semi-solid powder moulding based on the Shima-Oyane model. At beginning, the constitutive equation of Mg-6Zn powder materials was deduced and improved based on the semi-solid compression experiments. The materials constants of Mg-6Zn powder materials were obtained. This study simulated the semi-solid compression process of Mg-6Zn powder materials by MSC. Marc software. The relative density and displacement of powders were simulated and was proved by the experiments. The influence of forming temperature on the semi-solid powder moulding process was studied. The results show that the forming temperature has little effect on the relative density when the liquid fraction is less than 10%, and the relative density gradually increases and tends to be stable with the progress of compression. The stress of semi-solid powder moulding is concentrated at both ends of the edge of the cylindrical blank. The minimum stress locates in the "belly" ar

关 键 词：半固态粉末成形 医用Mg-6Zn合金 本构方程 数值模拟 

分 类 号：TF125.22[冶金工程—粉末冶金]