(北京科技大学 新材料技术研究院，北京 100083)
摘 要: 在氢气压力为0.2 MPa、熔体温度为1 200 ℃条件下采用定向凝固法制备d 45 mm×120 mm的藕状多孔纯铜棒材，研究藕状多孔金属的压缩变形过程及其影响因素，分析藕状多孔材料的压缩变形机理，采用线性回归分析方法建立藕状多孔材料的压缩变形本构关系。结果表明：藕状多孔铜的压缩变形过程分为弹性变形、以孔壁塑性屈曲为主的大塑性变形和密实化3个阶段；大塑性变形阶段的主要变形机理是孔壁先呈波形弯曲，然后产生塌陷和折叠变形；藕状多孔铜沿平行气孔方向静态压缩时应力—应变曲线受应变速率影响很小。
关键字: 藕状多孔金属；定向凝固；变形行为；本构关系
（Advanced Materials and Technologies Institute, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:Lotus-type porous copper bars of 45 mm in diameter and 120 mm in length were fabricated by unidirectional solidification at hydrogen pressure of 0.2 MPa and molten temperature of 1 200 ℃. The compressive deformation process and its effect factors were investigated. The deformation mechanism of lotus-type porous copper was also analyzed and discussed. The compressive mechanical model of lotus-type porous metals was established using the method of linear regression. The results show that the deformation of lotus-typed porous copper consists of three stages of elastic deformation, large plastic yield deformation with mainly pore wall buckling, collapse and densification. The main deformation mechanism in the large plastic deformation stage is that the pore walls buckle in a periodic wave and then collapse and fold. The strain rate has little effect on the compressive stress parallel to the direction of pores.
Key words: lotus-type porous metal; unidirectional solidification; deformation behaviors; constitutive relation
ISSN 1004-0609
CN 43-1238/TG
CODEN: ZYJXFK
ISSN 1003-6326
CN 43-1239/TG
CODEN: TNMCEW