不同组装方式对PCBN物相的影响

Effect of different assemby ways upon PCBN phases

PCBN已成为现代切削加工中不可缺少的重要刀具材料,本文使用石墨罐、石墨罐+钼杯、石墨罐+钼杯+NaCl管三种不同的组装方式在UDS-Ⅱ型六面顶液压机上进行PCBN的合成,合成压力用油表压来标示,烧结温度用温度显示仪来监测,控制在1350℃～1500℃之间,保持该温度5～10 min,三种组装方式的合成条件相同.合成后所得的PCBN片经粗磨、抛光后用于金相及X-ray分析测试.结果表明,在三种组装方式下,PCBN生成主要物相均为CBN相及相关的粘结相,在该合成压力、温度范围内也没有发生CBN→hBN的可逆转化,组织结构、性能无明显差异.为简化组装方式、降低合成成本,同时最大限度的防止杂质进入PCBN,合成组装方式可采用石墨罐+钼杯.

In the modem machining process, PCBN has become an essential important cutting tool material. In the paper PCBN is synthesized in UDS - Ⅱ six-anvil hydraulic press in three different assembly ways with pure graphite pot, pure graphite pot ＋ molybdenum cup, pure graphite pot ＋ molybdenum cup ＋ NaCl tube. The pressure is showed by the oil-pressure meter, the sintering temperature is monitored by the temperature meter. The temperature is arranged within 1300℃-1500℃ for 5 - 10 minutes, the synthetic conditions for the three assembly ways remain the same. Then the synthesized PCBN are kibbled, polished and then analyzed by metallographical microscope and X - ray. The results indicate that, under three assembly ways, the main phases in the synthesized PCBN are CBN and correlative binder, there is no reversible conversion from CBN to hBN, no distinct difference in configuration and capability. In order to simplify the assembly way, reduce the synthesizing cost, and furthest avoid impurity entering into PCBN, we can introduce the technique of graphite pot ＋ molybdenum cup.