Ultraviolet-ozone assisted ultrasonic vibration cutting for extending diamond tool life

Ultrasonic vibration cutting (UVC) has proven its effectiveness in suppressing the severe chemical wear of diamond tools in machining of metals with strong chemical affinity to carbon, and the formation of inert oxide film on the freshly cut metal surface is expected to further extend the tool life due to the oxide’s passivation effect. Based on the existing tool wear suppression mechanism to slow the diamond graphitization, this paper proposed ultraviolet-ozone assisted UVC to further enhance the oxide formation and improve the diamond tool life. A numerical model for calculating the oxide formation rate is developed to study the influence of supplying gases with different oxidizing capabilities. Meanwhile, an in-situ ultraviolet-ozone assisted UVC system is in-house built, and the diamond tool wear for cutting of stainless steel and tungsten are studied. Experimental results show that, compared to air, oxygen and ozone, ultraviolet-ozone assisted UVC demonstrates the highest oxide growth rate and the longest tool life accordingly, which further verifies the theory that metal oxidation performs an important role in suppressing the chemical wear of diamond tools. [Display omitted] •Ultraviolet-ozone assisted UVC is presented as a novel method for suppressing the chemical wear of diamond.•The gas penetration process and oxide formation speed are theoretically analyzed and numerically modeled.•Experiments validated the proposed tool wear suppression mechanism and the UV-O3 UVC method.•High-quality mirror surface on tungsten and significantly prolonged tool life are obtained by applying the UV-O3 UVC method.