多孔铜合金高温压缩蠕变行为的数值模拟

采用RDL05电子蠕变疲劳试验机，在不同温度（550，600，650，700℃）以及不同应变速率（10-4，10-3，10-2／s）条件下对多孔铜合金进行高温压缩实验，获得多孔铜合金真应力一应变曲线，计算并得到相应温度下的蠕变本构方程．采用ANSYS软件对多孔铜合金进行高温压缩蠕变模拟，研究了孔径、载荷、孔形等因素对多孔铜合金蠕变性能影响．研究结果表明，孔径越大，温度、载荷越高，多孔铜合金蠕变变形越大，蠕变速率更快，蠕变性能越不稳定；在蠕变过程中，内棱孔壁处容易引起应力集中；孔隙形貌对多孔铜合金结构影响很大，随着孔形边数的增加，多孔铜合金结构越不稳定；在相同载荷下，三角形孔压缩量最小，圆形孔压缩量最大．

Finite element simulations for high temperature compression creep of porous Cu alloy

The compression deformation were investigated under different etevated tempera- tures and strain rates, in order to obtain the creep constitutive equation. The effects of ap- erture load and pore shape on the compression properties of porous Cu alloys were studied by simulating the creep compression deformation at elevated temperature using ANSYS software. Pore size, load and pore shape are the main factors on the high temperature com- pression creep properties in porous Cu alloys. Samples with larger pore size, higher load and temperature showed inferior compression creep resistance such as bigger creep deforma- tion, faster creep rates, and more unstable creep deformation. Stress concentrations gener- ating around the edge in the wall of the pore were observed. The shape of pore has a severe influence on the structure properties of the material, i.e. every increase of pore edge corre- sponds to a decrease of stability in structure.