Waterjet and abrasive waterjet surface treatment of titanium: a comparisonof surface texture and residual stress

In this study, commercially pure titanium (cpTi) and a titanium alloy (Ti6A l4V) were subjected to waterjet (WJ) peening and abrasive waterjet (AWJ) pe ening surface treatments. The texture and in-plane biaxial residual stress of the treated surfaces were quantified using contact profilometry and X-ra y diffraction, respectively. Regardless of the specific process conditions, the surface residual stresses resulting from WJ and AWJ peening of both ma terials were compressive. Residual stresses in the Ti6Al4V ranging -400 les s than or equal to sigma less than or equal to -30 Mpa, whereas stresses in the cpTi treated with the same conditions ranging -200 less than or equal to sigma less than or equal to -60 MPa. Residual stresses resulting from WJ peening increased with the WJ pressure whereas those resulting from AWJ pe ening decreased with an increase in both jet pressure and abrasive size. Th e surface roughness of the metals did not change appreciably with WJ treatm ent, but AWJ peening resulted in a significant increase in roughness. There fore, AWJ peening may serve as a new method for introducing compressive res idual stresses in engineering components that also require rough surfaces. (C) 2001 Elsevier Science B.V. Ali rights reserved.