Abrasive Waterjet Machining-A State of Art

Abstract

With the advent of newer materials and intricate shapes of components, unconventional methods of material removal have been developed. Abrasive waterjet machining (AWJM) is one of such processes of material removal. This paper briefly describes the basic features of AWJM, such as, its mechanism of material removal, advantages, disadvantages and application possibilities. I. Introduction The principle of rain-erosion phenomenon occurring on high speed aircrafts is well-known and is utilized in high pressure jet -cutting where a high pressure jet of small diameter is directed at a target material at a high velocity. Abrasive waterjet cutting (also called Abrasive waterjet machining or AWJM) is similar to laser beam machining and electron-beam machining in one respect. The similarity lies in concentrating a given amount of energy into a small point to cause material removal. Abrasive waterjet cutting involves using an extremely fine jet of water travelling at high velocity, into which an abrasive material is mixed for cutting hard materials such as granite and titanium. This process makes a very fine cut into the material, known as a kerf. The kinetic energy possessed by a jet increases with the velocity. Hence in precision jet cutting with small diameter jets, though the mass flow rate is reduced, the kinetic energy possessed by the jet increases with the increase in velocity imparted by high pressure. A Schematic Illustration of the Experimental Set-Up of AWJM is shown in Figure 1.