ENERGY AND RESOURCE EFFICIENCY IN THE ABRASIVE FLOW MACHINING PROCESS: AN ASSESSMENT OF ENVIRONMENTAL AND ECONOMIC VIABILITY WITHIN A UK PRECISION MACHINING SME

摘要

Environmental performance of the abrasive flow machining (AFM) process is currently not well understood. Its flexibility as a manufacturing process has only recently been realised in SMEs (Small to Medium Enterprise) as a feasible automated alternative to deburring and polishing of complex geometry by hand, and as an alternative to honing and grinding using semi-automated machinery. Economic benefit is still the main driver in the commercial uptake of environmentally-sustainable technologies; despite AFM's known flexibility and capability, this paper presents systematic research by focusing on AFM including, 1) assessing and comparing the requirements of competing processes (values sourced from), 2) their power consumption, 3) operating conditions, 4) cost of pre-requisite ancillary equipment and 5) embodied energy and recyclability of machine structures and consumables. Three workpiece scenarios are laid out (distinguished by feature-count, processing time, tolerance-demands and setup-count) for comparison purposes - the trade-off between environmental and economic cost is described with reference to industrially-significant quality measures such as repeatability, accuracy, precision and uniformity. Key findings in this research include the comparatively high energy demand from natural gas-fired warm air blow-heaters, a requirement for the heating of spaces for human labour activity. Performance is shown to be limited by design - the AFM machine in this study operates with only an additional 22% of current between idle mode and production mode suggesting sub-assembly redesign may be of benefit. To conclude, the AFM process offers a clear route to sustainable part-finishing, low-maintenance and high potential for 'greening' considering factors in addition to running cost.