IJPST Home • Issue Contents

Evaluation of Surface Properties of Silicon Nitride Ceramics Treated with Laser Peening
K. Saigusa, K. Takahashi and N. Sibuya

Laser peening (LP) is a process that has been mainly applied to metals. However, few studies have applied LP to ceramics. In this study, laser peening without coating (LPwC) was applied to silicon nitride reinforced with silicon carbide (Si3N4/SiC). Smooth, laser-peened, and shot-peened specimens were prepared, and the surface conditions, surface roughness, and residual stresses were investigated. The surface roughness increased after LP due to laser ablation. When the LP parameters such as power density and coverage were too high, cracks initiated on the surface. Further, when appropriate LP parameters were selected, a compressive residual stress of up to 230 MPa was introduced on the surface and the depth was about 50 μm. Although the magnitude of the surface residual stress of the laser-peened specimen was smaller than that of the shot-peened specimen, LP was able to introduce a deeper compressive residual stress.

Keywords: Laser peening, silicon nitride, ceramics, residual stress, surface roughness, surface properties

Full Text (Open Access)