压力、功率梯度对金刚石性能的影响

本文旨在研究两面顶合成工艺中金刚石在生长阶段通过改变压力、功率梯度实现改变生长驱动力后对金刚石性能的影响，分析了相应的影响机理。在间接加热腔体结构中，金刚石生长过程采用两种压力、功率梯度进行合成，合成后对所得的样品进行了静压强度、冲击强度、表面形貌检测。结果表明：生长前期的压力和功率梯度增加两倍，生长后期梯度减缓，TTI和TI分别增加了10％。研究认为生长早期压力、功率大梯度（压力增幅大，功率降幅大）有利于提高晶体内部质量，生长后期压力、功率小梯度（压力增幅小，功率降幅小）有利于提高晶体外部质量。

Influence of gradient of pressure and power on diamond properties

Diamond synthesis experiment was conducted in a belt press by indirect heating method. Two sets of pressure and power gradient parameters were adopted during the growing period of diamond crystals. Static compress strength, impact toughness and thermal impact toughness as well as the surface morphology of the obtained diamonds were tested. The results analysis suggest that, during the early period of diamond growing, a large gradient of pressure and power (large pressure increase and large power decrease) provides efficient driving power which is favorable for diamond quick growth. While during the later period of growing, a small gradient of pressure and power (small pressure increase and small power decrease) can slower the growing speed of diamond,reducing the temperature ondulation,thus guaranteeing the quality of diamonds. An increase of TI and TTI of 10% was obtained respectively in our experiment.