FEASIBILITY STUDY OF MACHINING WITH ULTRAHIGH-PRESSURE DIRECTLY PUMPED ABRASIVE SLURRIES

THE ABRASIVE-WATERJET (AWJ) TECHNOLOGY INTRODUCED INTO THE MARKETPLACE IN 1983 WAS A BREAKTHROUGH IN MACHINING PROCESSES, ESPECIALLY FOR HARD-TO-MACHINE BRITTLE MATERIALS AND EXOTIC ALLOYS AND COMPOSITES. THIS PROPOSAL ADDRESSES ANEW CONCEPT OF FORMING AWJS THAT MAY PROVE TO BE ANOTHER BREAKTHROUGH IN MACHINING TECHNOLOGY. PREMIXED SLURRIES WILL BE DIRECTLY PUMPED UP TO 55,000 PSI TO FORM JETS WITH APOWER DENSITY AN ORDER OF MAGNITUDE HIGHER THAN CURRENT AWJ SYSTEMS. IN EXISTING SYSTEMS, ABRASIVES ARE ENTRAINED INTO A HIGH-VELOCITY WATERJET. SIGNIFICANT LOSS OF ENERGY OCCURS DUE TO THE WATER/ABRASIVE MOMENTUM TRANSFER. THIS LOSS WILL BE SIGNIFICANTLY REDUCED BY DIRECT PUMPING OF ABRASIVE SLURRY. THE POTENTIAL ADVANTAGES OF DIRECT-PUMPINGNOZZLES INCLUDE: (1) HIGH ENERGY TRANSFER EFFICIENCY, (2) CAPABILITY OF FORMING ABRASIVE-DENSE JETS, AND (3) CAPABILITY OF FORMING JETS WITH DIAMETERS AS SMALL AS 0.003 INCH (VERSUS 0.030 INCH FOR CURRENT AWJS). IN THIS PHASE I EFFORT, AN EXPERIMENTAL SETUP WILL BE PREPARED, AND AN EXPERIMENTAL INVESTIGATION WILL BE CONDUCTED TO RECOGNIZE SOME FEATURES OF THE FLOW CHARACTERISTICS OF HIGH-PRESSURE SLURRY JETS AND THEIR MACHINING CAPABILITIES. IN ADDITION, A TECHNICAL AND ECONOMICAL ANALYSIS WILL BE CONDUCTED. THE OVERALL FEASIBILITY OF HIGH-PRESSURE PUMPING OF ABRASIVE SLURRY WILL BE ASSESSED AND AREAS OF FUTURE INVESTIGATION WILL BE DETERMINED.