Modeling of heat partitioning and temperature rise at the tool-chip interface in diamond turning of the PBX surrogate

Abstract

To predict the heat partition ratio and chip temperature rise in the diamond turning of a PBX surrogate, a comprehensive model is built in this work. The newly created model takes into account the removal and friction law of powder chips at the tool tip in addition to the diamond tool and important process parameters. The cutting heat generation and distribution rule are clearly outlined thanks to the successful integration of the momentum theorem (related to cutting force) and energy conservation theory (related to cutting heat). The following findings came from the high-speed face turning experiment based on simultaneous force-thermal monitoring: 1) The friction heat at the tool-chip interface is the primary cause of the temperature increase in the chip, and decreasing the heat partition ratio is advantageous for lowering the risk of thermochemical reactions of powder chips. 2) It is effective to suppress the proportion of heat obtained from powder chips by optimizing the diamond tool with a negative rake angle and reducing the equivalent cutting friction coefficient. 3) The most important aspect affecting the chip temperature rise is the cutting speed. Improving the tool-chip friction conditions and lowering the maximum cutting speed are essential for ensuring PBX machining safety.