Versatility of Waterjet Technology: From Macro to Macro Machining for Most Materials
Waterjet technology has matured rapidly and become one of the mainstream precision machine tools since commercialized in the late 1970’s. Waterjets have several inherent features that are superior to most conventional machine tools. Abrasive-waterjets are nowadays highly automated with PC-based CAD/CAM software that controls and operates the hardware (pump, nozzle, abrasive feeding, traverse, and accessories) for precision machining. Most sources of machine errors have been minimized for optimum operations. Abrasive-waterjets are capable of machining most materials up to about 0.3 m thick with square edges. Abrasive-waterjets are often applied as a finishing tool or, for extreme precision parts, as a net shaping tool. For very tough materials, the use of abrasivewaterjet for net shaping often helps to minimize the wear of expensive contact tools, leading to improved productivity and significant cost savings (reduction of work stoppage, part rejection, and tool replacement due to increase in the tool life). For fatigue-critical applications, low-cost secondary dry-grit blasting was successfully applied to induce residual compressive stresses on abrasive-waterjet-machined edges of aircraft metals, enhancing their fatigue lives at least three times over those of CNC-milled counterparts. Intensive R&D has been underway to develop μAWJ nozzles for abrasive-waterjet micromachining. Photos and samples of abrasive-waterjet-machined parts, both large and small and made of various materials, are shown to demonstrate the versatility of an abrasive-waterjet as a precision machine tool.