Surface integrity of SLM manufactured meso-size gears in laser shock peening without coating

The present work aimed to improve the surface integrity of selective laser melting manufacturing (SLM) manufactured 10 mm sized meso gears using unconventional Laser Peening without Coating (LPwC) technique. To accomplish LPwC on low energy in range 200 mJ 1000 at Hz were applied underwater gear root and fillet gap generating significant compressive residual stresses (from +73 MPa −298 MPa). Besides surface, stresses, average roughness (Ra), arithmetical mean height (Sa) parameters material ratio curve also considered as a part study. Notable improvement was achieved Sa, it improved over 50 % while considerable Ra has been observed. Scanning electron microscopy confirmed that void porosity seen unpeened filled. backscatter diffraction analysis confirms grain refinement region up 100 μm depth. It observed multifold dislocation occurs within grain, generates sub-grain. sub-grain formation substantially inhibits further nucleation crack propagation owing an increase boundary density. Such justifies set objectives, outcome this research will pave foundation overall performance micro/meso parts process.