Ultrasonic vibration-assisted grinding of titanium alloy, a difficult-to-machine material, was attempted. Grinding with a constant load (7.8 N, 11.7 N, and 17.6 N), assisted by vibration in the radial direction of a straight wheel resulted in an increase of material removal by a factor of approximately 1.3. The pressure between the grinding wheel and workpiece was smaller with vibration support, and no thermal damage was observed on the ground surface. The specific grinding energy was lower for vibration-assisted grinding in the range of 8% to 18%. The variations in surface roughness of ground surfaces were suppressed. Furthermore, the hardness at a depth of 1 μm from the surface was increased by approximately 1.18 times with vibration support. These results suggest that vibration assistance is useful for grinding titanium alloy.

This study was performed to investigate the temperature distribution of wafers during rotary infeed grinding. While fixed abrasive grinding is a stable process for producing thin and flat wafers with high efficiency, it is essential to control grinding temperature to reduce subsurface damage. Here, we developed a Finite-Element-Method model to analyze the temperature distribution across the wafer surface during the grinding process, and an in-process temperature measurement device, which can identify three key parameters necessary for numerical analysis of wafer temperature: i.e., heat inflow from the grinding contact zone and heat outflow from the top and bottom wafer surfaces. Using our model and the identified parameters, we were able to not only obtain the temperature distributions in three-dimensions of the wafer and its variations over time but also to associate these distributions and variations with the grinding conditions, such as the feed rate and wheel speed.