Effects of coolant flow rate under ultrasonic vibrations transmitted to surface roughness in grinding SKD11 steel

The ultrasonic assisted machining method is now widely applied and supported in machining processes such as drilling, turning, milling and especially grinding. This paper presents the effect of coolant flow rate q (3.5, 4.5 and 5 l.min-1 respectively) under ultrasonic vibrations transmitted in grinding SKD11 steel. The surface roughness Ra was used to evaluate the impact. The results show that, when no ultrasonic vibrations were transmitted, the surface roughness values are approximately equivalent when changing the coolant flow rate. However, when transmitting the ultrasonic oscillator to the coolant, the coolant flow rate increases, the effect of ultrasound is clear. The results show that the surface roughness of the workpiece decreases as the coolant flow increases. In other words, the coolant was transmitted by ultrasonic vibrations that clean the grinding wheel surface, removing the grinding chips that stick to the space between the abrasives grains, ensuring the grindability of grinding wheels.