Energy Efficacy of a Novel CRUM Process for Machining of Ceramic Material

Background: The processing and machining of advanced ceramic material, silicon nitride have is quite challenging without surface damaging, surface, and sub-surface micro-cracks due to their extreme hardness and toughness. Previous researchers have worked on machining of silicon nitride through a grinding process at very high cutting speed and high cutting force with a very low material removal rate (MRR). Some researchers have worked to resolve these problems using laser-assisted machining. In the Laser-assisted process, high temperature reduces the silicon nitride strength and increases the MRR at low cutting force in the ductile regime, due to too high temperature arriving steep thermal gradients produce surface and subsurface cracks. Ultrasonic-assisted machining of ceramics provides solutions for eliminating thermal gradient problems, but it still affects the surface roughness of materials, because it promotes brittle fracture for the material removal process. Objectives: 1. To develop a novel, cost-effective, sustainable method for machining silicon nitride. 2. To compare the energy efficiency (Specific Energy) with other popular processes. Method: This research has employed a dual hybridization process with ultrasonic vibration and chemical assistance, known as chemically assisted rotary ultrasonic machining (CRUM). Findings: The feed rate is the main effective factor, and its contribution to cutting force is 76.06% and the specific energy (Energy consumption) is 95.15%. The CRUM process is found to be 5.22 times more energy efficient than the Common Grinding (CG) process. The CRUM process is 1.698 times more energy efficient than the Ultrasonic Assisted Grinding (UAG) process. Novelty: This work has achieved a novel chemically assisted rotary ultrasonic machining (CRUM) process to machine silicon nitride material. Keywords: Machining, Ceramic, Silicon Nitride, Mechanochemical Machining, Energy Efficiency