Investigation of surface topography formation mechanism based on abrasive-workpiece contact rate model in tangential ultrasonic vibration-assisted CBN grinding of ZrO2 ceramics

Ultrasonic vibration-assisted grinding is widely used as a highly efficient processing method for hard-and-brittle materials such as zirconia ceramic materials. Based on the characteristics of ultrasonic vibration assisted intermittent machining, combined with the motion characteristics of the single abrasive particles and adjacent abrasive particles, the abrasive grain-workpiece contact rate model between abrasive particles and workpieces during ultrasonic vibration assisted grinding is proposed. The grinding force, surface quality and the life of the grinding head are directly affected during the machining process. In the ultrasonic vibration assisted grinding process, the non-periodic distribution of the contact and separation between the grinding head and the workpiece is reflected, which increases the complexity of analysis in the ultrasonic vibration assisted grinding process. According to the model, the influence of machining factors (cutting speed) and vibration factors (amplitude, frequency) on the contact rate is analyzed. In addition, a contrast experiment is designed to analyze the surface morphology between ultrasonic vibration assisted grinding and common grinding. And the surface quality is effectively improved by using ultrasonic vibration. Besides, a four-level and four-factor orthogonal experiment is designed. The surface roughness prediction model is established on the basis of the neural network of genetic algorithm, and the validity of the model is verified by the experiment.