Parametric Effects on Grit Embedment and Surface Morphology in an Innovative Hybrid Waterjet Cleaning Process for Alpha Case Removal from Titanium Alloys

AbstractAn innovative hybrid waterjet cleaning (HWJC) process which aims to combine the benefits of both abrasive waterjet (AWJ) and plain waterjet (PWJ) processes has been proposed in this paper as an innovative solution for bulk removal of thick alpha case from titanium alloys. In the HWJC process, AWJ is firstly applied to the target surface in order to remove the surface material to a near- desired depth; the PWJ operation is then applied to clean the AWJ-machined surface. The PWJ process is designed to remove the embedded abrasive particles from the AWJ-machined surface and to provide a polishing effect (reduction in surface roughness). In order to evaluate the performance of HWJC, a series of experimental runs have been conducted on Ti-6Al-4V with an alpha case layer. The influence of PWJ processing parameters on the efficiency of grit removal was examined. The results showed that the HWJC process can effectively reduce the area coverage of grit contamination. However, the grit removal efficiency is dependent not only on the operating parameters of the PWJ, but also upon the embedment behavior of the abrasive particles