采用粉末冶金工艺制备了不同体积分数的AlNp/Cu系列复合材料,研究了复合材料从50-550℃的热膨胀行为,对不同体积分数的AlNp/Cu复合材料发生热变形的温度范围进行了分析计算,测定了AlNp/Cu复合材料塑性变形后的软化温度。结果表明:AlN的加入能够提高铜基体的软化温度且对铜基体的热膨胀起到明显的约束作用;在孔隙与热应力共同作用下,AlN颗粒含量达到一定程度时,AlNp/Cu复合材料膨胀曲线随温度的上升将产生非线性变化;加热过程中热应力造成的基体塑性变形使热循环后复合材料存在残余正应变。
Pure copper and its composites reinforced with different volume fractions of AlN particles were prepared by powder metallurgy. The thermal expansion behavior of composites was studied from 50℃ to 550℃. The temperature range of matrix plastic deforming caused by thermal stresses was calculated with raises yidd rule. The soft temperature of AlNp/Cu after plastic deforming was measured. The soft temperature of copper matrix could be effectively improved and thermal expansion of copper matrix could be effectively restrained by the AlN particles; Under the action of porosity and thermal stresses, the thermal expansion curve of AlNp/Cu composites became non-linear with the particle volume contents increasing to a certain extent. The composites exhibited positive residual strain when cooled down from the peak temperature to room temperature because of the copper matrix plastic deformation caused by thermal stresses.