| High cutting temperature is always an important problem in difficult-to-machine materials cutting. An original idea about Cryogenic Pneumatic Mist Jet Impinging (CPMJI) Cooling is put forward in this paper. The kernel of the idea is that CPMJI that involves two-phase heat convection, jet impinging and full vaporization is used to enhance the heat transfer potential of cooling medium and obtain the best cooling effect. Some works have been done in this paper:1. Experimental equipment of CPMJI has been set up. It can produce a cryogenic mist jet with desirable parameter by change its spout and adjust gas pressure and liquid pressure.2. The parameters of cryogenic pneumatic mist jet impinging has been measured. The effect about the pressure of gas and liquid and jet impinging distance to the flux of mist jet, jet impinging speed and diameter of droplet have been studied.3. Heat-transfer experiments based on CPMJI cooling technology have been completed. By transient and steady-state experiments, critical heat flux (CHF) and heat transfer convection parameter which can denote the capability of heat-transfer of CPMJI were obtained under different work condition. By compare these parameters with that of cold air and conventional flood cooling method, the high efficiency cooling ability of CPMJI cooling technology has been validated on the way of heat transfer.4. Machining effects of CPMJI have been studied compared with other two cooling methods cold air and conventional flood cooling in the turning of titanium alloy. It is found that lower cutting temperature, longer tool life, better surface quality and better chip-breaking performance can reach employing with CPMJI. The remarkable ability of CPMJI cooling technology is validated preliminarily. |
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