Abstract: Difficult-to-cut materials with high strength and toughness are prone to the burnout of workpiece surface during grinding; However, the problems of high energy consumption and environmental pollution caused by conventional grinding coolant cannot be ignored. Using boiling heat transfer and heat storage technology to improve wheel thermal performance so as to realize enhanced heat transfer in grinding zone. A phase change heat storage composite wheel with high heat transfer coefficient and large heat capacity is developed, and heat transfer coefficient and equivalent heat capacity are analyzed. A composite wheel thermal performance analysis device is designed and manufactured to analyze for different factors as heat flux, injection amount of working substance and heat dissipation conditions on composite wheel thermal performance by monitoring temperature changes at multiple locations. Finally, the comparative experiment of dry grinding superalloy GH4169 are carried out. Results show that the composite wheel heat transfer coefficient can be increased 2-3 times compared with the traditional wheel, and the start-up time of working substance entering boiling heat transfer is 6-15 s. At the same time, increasing heat capacity of the wheel can effectively reduce heat accumulation as well as slow down temperature rise rate in grinding zone. Grinding temperatures of the phase change heat storage composite wheel under creep-feed deep dry grinding process are below 330 ℃, which can be reduced by 20 % compared with the traditional wheel.

Key words: grinding, super-abrasive wheel, superalloy, green machining, boiling heat transfer