Abrasive flow machining: a case study

Abstract Abrasive flow machining finishes surfaces and edges by forcing a flowable abrasive media through or across the workpiece. Abrasion occurs only where the media flow is restricted; other areas remain unaffected. It can process many selected passages on a workpiece simultaneously, reaching even typically inaccessible areas. Several or dozens of parts can be processed in one fixture, yielding production rates of up to hundreds of parts per hour. A variety of finishing results can be achieved by altering the process parameters. Tooling can be designed to be changed in minutes even in production applications. The AFM process boasts reliability and accuracy, typically yielding a 90% improvement in surface finishes with stock removal controllable to within 10% of the stock removed. The most labor intensive, uncontrollable area of production remaining in the manufacture of precision parts involves the final finish machining operations, which frequently absorb as much as 15% of the total manufacturing costs. Proper finishing of edges and surfaces affects more than the appearance or feel of a product; controlled, consistent edge and surface finishing can dramatically improve product performance and life while reducing direct labor costs. These operations have been identified as the single greatest hurdle remaining in fully automating the production of precision components. Abrasive flow machining for deburring, radiusing, sizing and polishing can be applied to an impressive range of finishing operations, providing uniform, repeatable, predictable results. With today's focus on total automation with machine tools in flexible machining systems, the AFM process offers both automation and flexibility in final machining operations as an integral part of the complete manufacturing cycle.