熔渗烧结钴浓度梯度对金刚石复合片力学性能的影响

研究了金刚石复合片超高压高温烧结钴相熔渗机理和钴浓度梯度对金刚石复合片力性能的影响。结果表明,组装方式不同导致液相钴向金刚石层渗透,引起硬质合金基体沿层界面向内出现明显的浓度梯度。对于基体中部置于高温区中心的组装方法得到的金刚石复合片,其层界面硬质合金侧的钴质量分数达到9.42%,远高于常规对装组装方式金刚石复合片的5.58%,抑制了硬质合金在层界面附近钴流失严重的现象,钴浓度梯度减小,该种组装方法得到的金刚石复合片抗冲击性能明显优于传统对装金刚石复合片。钴浓度梯度的差异没有影响金刚石复合片的耐磨性。

Effect of cobalt concentration gradient by infiltration sintering on the mechanical properties of polycrystalline diamond compacts

The infiltration mechanism of cobalt phase in the polycrystalline diamond compacts (PDC) by the ultra-high pressure and high temperature sintering was investigated, and the effect of cobalt concentration gradient on the mechanical properties of PDC was analysed. In the results, the different assembly methods result in the liquid cobalt permeating into the diamond layer, and the obvious concentration gradient appears in the cemented carbide matrix along the interface. For the PDC obtained by the assembling method with the middle of the matrix placed in the center of high temperature region, the mass fraction of cobalt phase reaches 9.42% in the interface of the cemented carbide, much higher than that of 5.58% for the PDC obtained by the conventional assembly method, which inhibits the serious cobalt loss of the cemented carbide near the interface, the cobalt concentration gradient decreases, and the impact resistance of the PDC obtained by this assembly method is much better than that of the conventional assembly method. The cobalt concentration gradient does not affect the PDC wear resistance.