Magnesium composites with hybrid nano-reinforcements:3D simulation of dynamic tensile response at elevated temperatures

镁基纳米混杂复合材料的高温动态拉伸响应三维模拟

3D numerical simulations of dynamical tensile response of hybrid carbon nanotube(CNT)and SiC nanoparticle reinforced AZ91D magnesium(Mg)based composites considering interface cohesion over a temperature range from 25 to 300℃ were carried out using a 3D representative volume element(RVE)approach.The simulation predictions were compared with the experimental results.It is clearly shown that the overall dynamic tensile properties of the nanocomposites at different temperatures are improved when the total volume fraction and volume fraction ratio of hybrid CNTs to SiC nanoparticles increase.The overall maximum hybrid effect is achieved when the hybrid volume fraction ratio of CNTs to SiC nanoparticles is in the range from 7:3 to 8:2 under the condition of total volume fraction of 1.0%.The composites present positive strain rate hardening and temperature softening effects under dynamic loading at high temperatures.The simulation results are in good agreement with the experimental data.

采用三维代表体元方法,并考虑界面内聚力,对碳纳米管和纳米SiC混杂增强AZ91D镁合金基复合材料在25~300℃动态拉伸响应进行三维数值模拟,并将模拟结果与实验数据进行比较。结果表明,在不同温度下,该纳米复合材料整体动态拉伸性能随着碳纳米管和纳米SiC颗粒的总体积分数和混杂体积分数比的增加而提高。在总体积分数为1.0%的情况下,当碳纳米管和纳米SiC颗粒的混杂体积比为7:3~8:2时,混杂强化效应最大。镁基混杂纳米复合材料在高温动载荷作用下表现出正的应变率硬化和温度软化效应,模拟结果与实验数据吻合较好。