渗氮＋离子注入对M2高速钢的表面复合改性

对比了分别经可控渗氮、离子注入形成TiN及可控渗氮 离子注入Ti∧2 后，M2高速钢精冲模的使用寿命。结果表明，采用可控渗氮 离子注入Ti∧2 的复合处理工艺，可使零件的使用寿命获得明显提高。断口分析、表面硬度测试、金相分析、XRD和AES分析表明，寿命的提高是由于：（1）用Jonsson经验公式算得的该TiN注入层的真实硬度为HV3000,TiN的超高硬度是寿命提高的根本原理；（2）该复合工艺可使M2高速钢表面TiN注入层获得较厚较硬的氮化过渡层、增强了膜基间的结合力，从而提高了零件的抗磨损和抗冲击性能；（3）渗氮层增加了钛离子的注入深度，获得了更宽的TiN改性层，用JT-PRⅡ所得到的模拟计算结果与此吻合得很好。

Modification of Combined Nitriding Plus Ion Implantation to M2 High Speed Steel

The life experiments of W6Mo5Cr4V2 high speed st eel dies treated respectivelly by controlled nitriding、 ion implantation with T i2++N2+ and a combined technique of controlled nitriding and implant ation with Ti2+ were made. The result shows that, compared with other two techniques, the combined technique can improve the life of the dies by a large margin. Besides the ultrahigh hardness of TiN coating, the thicker and harder n itriding layer, which transited from TiN coating to substrate of M2 high speed s teel, contributes greatly to the life improvement. The transition layer not onl y strengthens the binding force between coating and substrate, but also widens the depth of implanted Ti2+ ion which leads to a thicker TiN modification layer and consists with the computer simlation result of JT-PRⅡ software de veloped by oursleves.