热处理对粉末冶金法制备W_p/2024Al复合材料力学性能的影响

Effect of Heat Treatment on Mechanical Properties of W_p/2024Al Composites Prepared by Powder Metallurgy

利用粉末冶金法制备了钨颗粒体积分数分别为5%,8%,10%的Wp/2024Al复合材料,挤压态复合材料W颗粒分散均匀,沿挤压方向钨颗粒呈带状分布。复合材料经过热处理后拉伸强度得到提高,延伸率则发生下降;同一工艺制备的Wp/2024Al复合材料480℃固溶时抗拉强度达到最大值;随着固溶温度的升高,复合材料屈服强度有一定的增加,延伸率下降;随着W含量的增加,T4态复合材料的抗拉强度和屈服强度升高,而延伸率下降。断口观察表明,挤压态和热处理态复合材料断口上存在大量韧窝,W颗粒没有发生开裂,热处理态复合材料发生界面脱开现象。

The composites of 2024Al with 5 % （in volume） W particles, 8 % W and 10% W, respectively were fabricated by powder metallurgy method. In the extruded composites, the W particles uniformly dispersed in the 2024 aluminum matrix, and the clustering of the W particles also observed locally. After heat treatment, the tensile strength of the composites increased, and the elongation of the composites decreased. The ultimate tensile strength of Wp/2024Al composite treated in 480 ℃ solution achieved maximum. The yield strength increased and the elongation decreased, as the temperature of solution treatment increased. With the content of W particles increasing, the ultimate tensile strength of the composites increased and the yield strength of the composites decreased. Fractographic analysis revealed that there were many dimples on the fracture surfaces of extruded and heat-treated composites, the W particles did not crack and the heat treated composites showed interfacial decoherence of W particles.