Surface Integrity Evaluation of Brass CW614N after Impact of Acoustically Excited Pulsating Water Jet

Presented article is focused on surface integrity evaluation of brass CW614N form the sight of surface topography, structural changes in surface layers and strengthening character in subsurface layers after impact of acoustically excited pulsating water jet (PWJ). Surface topography was evaluated using optical profilometry. Structural changes in subsurface layer were observed based on mass material removal Δm [mg/s] and maximal depth of penetrance of PWJ hmax [mm]. Nano indentation measurement according to Berkovich were used to examination of strengthening character in subsurface layer. Disintegration of experimental samples was performed under constant technological conditions: hydraulic power of plunger pump Ph = 19 kW; round nozzle diameter d = 1.6 mm; feed speed rate v = 0.75 mm/s; pressure of plunger pump p = 38 MPa, stand-off distance of nozzle from target material z = 45 mm; ultrasound frequency f = 20.29 kHz and as variable factor was set power of ultrasound P on values 340, 360 and 380 W. In terms of surface topography experimental investigation proved that PWJ under selected conditions is not suitable for precision machining. Evaluation of the surface characteristics indicates that the chemical composition has a significant effect on material weight loss Δm [mg/s] and a maximum depth of penetration of PWJ hmax [mm]. Evaluation of characteristics of subsurface layer was observed strengthened area with lower elasticity.