WATER JET CUTTING

INTRODUCTION
In the battle to reduce costs, engineering and manufacturing departments are    constantly on the lookout for an edge. The water jet process provides many unique capabilities and advantages that can prove very effective in the cost battle. Learning more about the water jet technology will give us an opportunity to put these cost-cutting capabilities to work. Beyond cost cutting, the water jet process is recognized as the most versatile and fastest growing process in the world. Waterjets are used in high production applications across the globe. They compliment other technologies such as milling, laser, EDM, plasma and routers. No poisonous gases or liquids are used in waterjet cutting, and waterjets do not create hazardous materials or vapors. No heat effected zones or mechanical stresses are left on a waterjet cut surface. It is truly a versatile, productive, cold cutting process. The waterjet has shown that it can do things that other technologies simply cannot. From cutting whisper, thin details in stone, glass and metals; to rapid whole drilling of titanium; for cutting of food, to the killing of pathogens in beverages and dips, the waterjet has proven itself unique.

THEORY OF WATERJET CUTTING

Most waterjet cutting theories explain waterjet cutting as a form of micro erosion as described here. Waterjet cutting works by forcing a large volume of water through a small orifice in the nozzle. The constant volume of water traveling through a reduced cross sectional area causes the particles to rapidly accelerate. This accelerated stream leaving the nozzle impacts the material to be cut. The extreme pressure of the accelerated water particles contacts a small area of the work piece. In this small area the work piece develops small cracks due to stream impact. The waterjet washes away the material that "erodes" from the surface of the work piece. The crack caused by the waterjet impact is now exposed to the waterjet. The extreme pressure and impact of particles in the following stream cause the small crack to propagate until the material is cut through.

CONCLUSIONS AND FUTURE SCOPE

Since its development, water-jet machining has seen many improvements in its design. Water-jet cutting technology is one of the fastest growing major machine tool processes in the world due to its versatility and ease of operation. Manufacturers are realizing that there are virtually no limits to what water-jets are capable of cutting and machining. Machine shops of all sizes are realizing greater efficiency and productivity by implementing UHP water-jets in their operations. Water-jets are becoming the machine tool of choice for many shops. Since abrasive water-jet (AWJ) technology was first invented by Flow in the early 1980s, the technology has rapidly evolved with continuous research and development. What makes water-jets so popular? Water-jets require few secondary operations, produce net-shaped parts with no heat-affected zone, heat distortion, or mechanical stresses caused by other cutting methods, can cut with a narrow kerfs, and can provide better usage of raw material since parts can be tightly nested. As a result of the Flow Master PC control system and intuitive operation, water-jets are extremely easy to use. Typically, operators can be trained in hours and are producing high quality parts in hours. Additionally, water-jets can cut virtually any material, leaving a satin-smooth edge. These benefits add up to significant cost savings per part in industries that have traditionally defined productivity by cost per hour.The latest development in the field of water-jet cutting is the use of super water for cutting, which enhances both abrasive and non-abrasive water-jet cutting.