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一、引言烧结的高密度多晶金刚石复合材料在机械加工、工具修整、金属拔丝和岩石钻进诸方面显示出优异的性能。在上述应用中,有时烧结金刚石复合材料要经受循环的应力。特别在岩石钻进时,岩石以脆性方式被逐层破碎,钻头刃部实际上经受着复杂的循环冲击负荷。因此在设计这些部件时了解钻头刃部材料受到的冲击和疲劳情况是必要的。对 Al_2O_3陶瓷和金刚石那样一些脆性材料的疲动现象已报道过各种实验结果,处于循环应力下会使断裂应力降低。Huffine~〔1〕等人报
I. INTRODUCTION Sintered high-density polycrystalline diamond composites show excellent performance in machining, tool trimming, wire drawing and rock drilling. In these applications, sintered diamond composites are sometimes subjected to cyclic stress. Especially when the rock is being drilled, the rock is fragmented layer by layer in a brittle manner, and the drill bit actually experiences complicated cyclic impact loads. Therefore, it is necessary to know the impact and fatigue of the drill edge material when designing these components. Fatigue phenomena on some brittle materials such as Al 2 O 3 ceramics and diamonds have been reported for various experimental results, which reduce the stress at rupture under cyclic stress. Huffine ~ [1] et al