Characteristics of the surface of a titanium alloy following milling with abrasive waterjets

Abrasive waterjets have been used for many years for the cutting of materials. Abrasive particles are entrained into a rapidly moving jet of water which impinges onto a substrate. Material is removed by erosion processes and the jet fully penetrates the material being cut in a single pass. More recently, abrasive waterjets have been employed for the machining of materials where the abrasive waterjet does not penetrate the sample as is the case in abrasive waterjet cutting. Such a technology may be employed to mill components in materials that are difficult to machine by conventional methods. Due to the differences in flow patterns, the erosion conditions are very different to those occurring in conventional cutting. This work examines the abrasive waterjet milling behaviour of Ti6Al4V in terms of the surface properties of the milled component, such as roughness, waviness and level of grit embedment. The properties of the surface following milling depend strongly on the milling parameters, such as jet-workpiece traverse speed, impingement angle, waterjet pressure and abrasive size.