WC-Co涂层磨削过程中的温度与相变

针对WC-Co涂层在磨削中磨削温度会引起相变,进而导致磨削缺陷的问题,以DMU70V数控铣床为平台进行WC-Co涂层磨削实验,利用K型热电偶和DGF40N光纤式红外测温仪测量磨削温度,借助x-射线衍射仪分析磨削前后WC-Co涂层物相组成.实验结果表明,利用热电偶测得的磨削温度与根据磨削过程中WC-Co涂层物质相变推测得到的磨削温度相差较大,利用WC-Co涂层物质相变推测的磨削最高温度与DGF40N光纤式红外测温仪测得的磨削最高温度一致,说明可以利用WC-Co涂层物质相变来推测磨削最高温度,为一些不能直接测量磨削温度的场合提供了新方法.WC晶粒在WC-Co涂层干磨削时大多异质生核,磨削后产生的WC晶粒粒度大,从而导致WC-Co涂层的强度下降,WC-Co涂层不宜干磨削.

Temperature and phase transformation in grinding process of WC-Co coating

Aiming at the problem that the phase transformation caused by the grinding temperature will lead to the grinding defects in the grinding process of WC-Co coating, a DMU70V computerized numerical control(CNC)milling machine was used as a platform to carry out the grinding experiments of WC-Co coating. A K-type thermocouple and a DGF40N optical fiber type infrared radiation thermometer were used to measure the grinding temperature, and the phase constituent of WC-Co coating before and after grinding was analyzed with an x-ray diffractometer. The experimental results show that the grinding temperature measured by the thermocouple is quite different from that speculated with the phase transformation of WC-Co coating in the grinding process. However, the highest grinding temperature speculated with the phase transformation of WC-Co coating is consistent with that measured by the DGF40N optical fiber type infrared radiation thermometer. It means that the phase transformation of WC-Co coating can be used to speculate the highest grinding temperature, and thus a new method is offered for the situation where the grinding temperature can not be directly measured. Most of WC grains heterogeneously nucleate in the dry grinding process of WC-Co coating. The WC grains with bigger grain size generate after the dry grinding, which will decrease the strength of WC-Co coating. And thus, it is suggested that the dry grinding is not suitable for the WC-Co coating.