定向凝固多孔Mg-Zn合金的制备及气孔结构  

Fabrication and Pore Structure of Directionally Solidified Porous Mg-Zn Alloy

作　　者：肖心雄 刘源[2,3] 金青林[1] 周灿旭 张华伟[2,3] 李言祥[2,3] 李再久[1] Xiao Xinxiong;Liu Yuan;Jin Qinglin;Zhou Canxu;Zhang Huawei;Li Yan-xiang;Li Zaijiu(Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China;School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China;Key Laboratory for Advanced Materials Processing Technology,Ministry of Education,Tsinghua University,Beijing 100084,China)

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]清华大学材料科学与工程学院,北京100084 [3]先进成形制造教育部重点实验室(清华大学),北京100084

出　　处：《稀有金属材料与工程》2021年第2期497-503,共7页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China (51771101)。

摘　　要：采用Bridgman型定向凝固法制备出藕状多孔Mg-Zn合金。研究了不同锌含量和氢气压力对气孔形貌的影响。通过理论计算对Mg-1Zn(质量分数,%,下同)合金的孔隙率进行了预测。结果表明,锌元素的加入会对孔结构产生重大影响。随着Zn含量从0%增加到2%,平均孔径增加。随着氢气压力从0.1 MPa增加到0.6 MPa,Mg-1Zn合金的孔隙率明显降低。基于氢气在多组分熔融金属中溶解度的计算模型,Mg-1Zn合金铸锭凝固高度为20 mm的不同氢压孔隙率的计算结果与实验的结果比较吻合。通过组织观察表明,随着Zn含量的增加,凝固组织由柱状晶转变为等轴晶。此外,研究了在不同凝固阶段孔的形成过程,可为在生物医用材料中应用的定向凝固多孔Mg-Zn合金的制备提供理论依据。Lotus-type porous Mg-Zn alloys were fabricated by the Bridgman-type directional solidification method. The pore structure and porosity of Mg alloys at different Zn contents and hydrogen pressures were studied. The porosity of Mg-1 wt% Zn alloy was predicted through the theoretical calculation. The results show that pore structure can be influenced by the addition of Zn element. As the content of Zn increases from 0 wt% to 2 wt%, average pore diameter increases. The porosity of Mg-1 wt% Zn alloy clearly decreases with increasing the hydrogen pressure from 0.1 MPa to 0.6 MPa. Based on a model for estimating the solubility of hydrogen in multi-component molten metals, the calculated results of porosity at the solidification stage(20 mm height) with a changed hydrogen pressure in Mg-1 wt% Zn alloy are in good agreement with the experimental results. Through observations of the microstructures, the column grains of Mg-Zn alloy change into equiaxed grains as the content of Zn increases. Also, the formation of pore at different solidification stages was studied, which can supply theoretical basis for the fabrication of Gasar Mg-Zn alloy in the biomedical applications.

关 键 词：多孔镁锌合金 Gasar工艺 定向凝固 

分 类 号：TG146.22[一般工业技术—材料科学与工程]