Next-Generation Waterjet Technology for High-Speed Precision Machining of SiC Ceramic Matrix Composites

A next-generation wataerjet technology will be developed for low-cost, high-speed, and precision machining of silicon carbide ceramic matrix composites (SiC CMCs). The new process will have cutting power equivalent to that of a conventional abrasive-waterjet (AWJ) operating at 1500 MPa while possessing all the inherent advantages of AWJs over other fielded machine tools; at such a super-high pressure, no affordable materials could survive. The overall improvement by combining advantages of AWJs and the superior cutting power of the non-contact new process would allow a 10-fold or more reduction in time and costs to machine CMCs, a significant reduction in part rejection/rework, and decreased maintenance costs of machining tools. The new nozzle made of super-hard CVD diamond and the abrasive jet will be miniaturized to fit into tight spaces, cut thin kerfs, and turn sharp corners. In particular, the miniaturized abrasive jet could be readily applied for micromachining. The new abrasive jet will be adapted to OMAX¡¦s existing JetMachining Center (JMC) with minimum engineering efforts for automated machining. A versatile JMC with a dual-jet option will be subsequently offered for pseudo and true 3D machining common and hard-to-cut materials with low-cost AWJs and high-speed new abrasive jets, respectively. BENEFITS: We anticipate that the proposed development would offer a cost effective, high-speed, precision tool for automated machining of silicon carbide ceramic matrix composites (SiC CMCs). The key advantages of the development are considerable boost in the cutting power and efficiency, non-contact machining, and miniaturization of nozzle and jet. The new process will have the cutting power equivalent to that of a 1500-MPa abrasive-waterjet (AWJ) while possessing all the advantages of AWJs over currently fielded tools. Miniaturization of the new nozzle and abrasive jet will facilitate micromachining that cannot be achieved with conventional AWJs. The new process will leverage the proven PC-based robotic platform, OMAX JetMachining Center or JMC (http://www.omax.com/machines.php), for automated machining. Long-life wear resistant parts will be fabricated with fast-grown super-hard CVD diamond made with a patented process. With the new process incorporated into the JMC, OMAX will extend its technological lead as a premier manufacturer of ultrahigh-pressure waterjet machining equipment and continue the extraordinary growth path in the recent years (30% in 2004 and 40% in 2005). For versatility, we will develop a dual-jet JMC so that users will have the choice of using the low-cost AWJ and the high-speed new abrasive jet for machining common and hard-to-cut materials. With the improved cutting power and efficiency and the added micromachining capability, we will add in Phase II a rotating part holder to facilitate pseudo 3D machining (multi-machining is one of the unique features of waterjet technology). True 3D machining will be accomplished by adding a second rotating axis to the part holder. We are confident that the above sequence of events spurred by the proposed development will lead to a state-of-the-art veratile tool capable of machining virtually any materials cost and time effectively.