Oil Jet Peening Device

Design and Development

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Introduction of compressive residual stresses (CRS) on the dynamically loaded components improves the crack initiation life. The oil jet peening process developed is capable of generating high magnitude of CRS with a better surface, less erosion and better coverage.This process uses a high velocity oil jet instead of shots to impinge upon the component surface. The surface of the components is repeatedly hit by multiple of oil droplet. The oil droplets generate an impact pressures that exceed the yield strength of the material.

At every drop impingement, the pressure builds up within a few milliseconds and causes local plastic deformation at the spot of impact, which is constrained by the surrounding materials thus producing CRS at the surface.The system permits use of nozzles of different geometries, peening at different oil pressures and nozzle and specimen travelling speeds . Preliminary tests conducted on aluminium alloys and steel samples indicate the induced CRS upto 100 MPa in AA 6063 T6 and and 200 MPa in En 8 with better surface finish.