An experimental study on the creep feed grinding of laser macro-structured alumina considering constant material removal volume

Abstract

Engineering ceramics such as alumina have found special applications in aerospace, electronics, and automotive industries due to their superior mechanical and thermal properties. Among these properties, chemical stability at high temperatures, high strength to weight ratio, hardness, strength, wear, and corrosion resistance are of prime importance. Due to these superior properties, processing of these ceramics encounters some difficulties and requires special machining processes such as diamond grinding; in addition to high manufacturing costs, this technique suffers from noticeable challenges such as high grinding forces and temperatures which may lead to serious surface damages. To overcome these challenges, in recent years, laser-assisted grinding has been introduced; in this process, laser source is used to preheat or structuring the workpiece surface in order to reduce grinding forces and temperatures. In this research, first four different patterns were created on alumina using a pulsed laser. Then, these weakened structures were machined using creep feed grinding. In order to provide a better understanding from the effect of each pattern, the volume of the material that can be removed was kept constant in all four patterns. Finally, the effect of created patterns on grinding forces and surface roughness has been studied. Besides, scanning electron microscopy has been used to investigate possible surface damages. The results showed that the normal and tangential forces in the non-structured case were 2 and 2.7 times higher than the forces recorded in the best patterned samples. However, no significant effect of the created patterns on the surface roughness was observed. Furthermore, serious heat damage and cracks were not observed in the structured workpieces, but non-structured workpieces were crushed during operation. Among the created patterns, pattern with perpendicular grooves to the grinding direction was introduced as the best.