中文摘要：

通过粉末冶金热压烧结制备不同碳化钨（WCP）含量（3vol%、9%和15vol%）的Cu/WCP颗粒增强复合材料。控制Pmax保持不变的条件下,研究了应力比（R=0.1、0.3和0.5）对Cu/WCP颗粒增强复合材料裂纹扩展速率的影响。结果表明：随着应力比R的增加,Cu/WCP颗粒增强复合材料的疲劳裂纹扩展速率da/dN逐步降低,疲劳寿命逐步增加。随着应力比R的增大,疲劳裂纹断口的塑性断裂越来越明显,裂纹尖端钝化越显著,且粗糙程度和二次裂纹数量增加。

英文摘要：

Cu/WCp composite with different contents （3vol%, 9vol% and 15vol%） of tungsten carbide （WCp） was prepared by powder metallurgy hot-pressing sintering. Keeping the same value of Pmax, the influences of stress ratio （R=0.1,0.3 and 0.5） on the crack propagation rates of Cu/WCp composite were studied. The results show that with the increase of stress ratio R, the fatigue crack propagation rate （da/dN） of Cu/WCp composite gradually reduces, and the fatigue life gradually increases. With the increase of stress ratio R, the plastic fracture of fatigue crack fractrue becomes obvious, the blunting of crack tip is more obvious, the roughness and the numbers of secondary cracks increase.