The main disadvantage of WJM is the low efficiency of energy transfer between the jet and the work piece. This produces low cutting rates, which limits the utilize of the water jet for machining of comparatively soft materials. For any engineering material, AWJM can be employed. However, the energy efficiency of AWJM is still small. Mixing of water and abrasives limits the minimum jet diameter that can be used.
In ice jet machining (IJM), the abrasives are changed by ice particles that form the ice jet. Since the hardness of the ice particles are fewer than that of the abrasives, minor material removal rates are expected, compared to AWJM. However, the cost reduction and the good environmental impacts make IJM even better. IJM is used in the food, electronic, medical, and space industries where contamination is impossible.
Ice particles are created using either stream freezing (<500 μm) or ice particles supply (>500 μm) into the stream. In the latter case, ice cubes, supplied from an icemaker, are fed to a grinder. Solid CO2 is added to prevent the crushed ice from melting as shown in Fig.1. The crushed ice is then fed throughout the machining nozzle. Prior to the nozzle the water is also cooled by passing through a coil that is submerged in liquid nitrogen. Geskin et al. (1995) reported a substantial development in the machining characteristics due to the entrapment of ice in the cutting nozzle (see below Table ).