A Study on Laser Assisted Machining for Silicon Nitride Ceramics (I) - Preheating Characteristics and Oxidation Behaviors of Silicon Nitride Ceramics with Machining Parameters -

Silicon nitride is widely used as an engineering ceramics because it has high strength, abrasion resistance and corrosion resistance even at high temperature. However, machining of silicon nitride is difficult due to its high hardness and brittleness. Laser assisted machining(LAM) allows effective cutting using CBN tool by locally heating the cutting part to the softening temperature of YSiAlON using the laser beam. The effect of preheating depending on process parameters were studied to find out the oxidation mechanism. If silicon nitride is sufficiently preheated, the surface is oxidized and $N_2$ gas is formed and escapes from the material, thereby making the cutting process more advantageous. During laser preheating process before machining, high temperature results in strong oxidation which makes the bloating, silicate layers and micro cracks. Using the results of these experiments, preheating characteristics and oxidation behavior were found out.

질화규소 세라믹의 레이저 예열선삭에 관한 연구 (I) - 공정변수에 따른 질화규소의 예열특성 및 산화거동 -