摘要

Purpose - Grinding may generate high temperature along the arc of grinding zone, especially during the grinding process of difficult-to-machine materials. It can cause thermal damage to the ground surface and poor surface integrity. Conventional cooling methods based on large amounts of water-oil emulsions can be both ineffective and environmentally unacceptable. The purpose of this paper is to offer a new high efficiency cooling method cryogenic pneumatic mist jet cooling (CPMJ) to enhance heat transfer in the grinding zone during grinding of difficult-to-machine materials. Design/methodology/approach - CPMJ equipment is a set up, which can produce water mist of 5 degrees C with jet velocity above 150 m/s and mean particle size below 20 mu m at the impingement distance of 10-40 mm on the symmetry axis. To validate the cooling efficiency of CPMJ equipment, heat transfer experiments were carrying out on it. Finally, CPMJ was applied to the grinding of titanium alloy to verify its cooling effects. Findings - With high penetrative power and water mist of 5 degrees C, CPMJ can greatly improve heat transfer efficiency in the grinding zone. Experimental results, including heat transfer experiments and grinding experiments, indicate that CPMJ has strong cooling ability and can offer better cooling effects compared with cold air jet and traditional flood cooling method. With CPMJ cooling method, grinding zone temperature can be effectively reduced and good surface quality can be achieved during grinding of titanium alloy. Originality/value - CPMJ cooling method is an effective and pollution-free way to solve the thermal problems during grinding of difficult-to-machine materials.