Tool wear and surface finish in high speed milling of aluminum bronze

Aluminum bronze C95800 is used extensively for the manufacture of propellers because of its mechanical strength and corrosion resistance. Typically these components are machined from large castings and then hand ground and polished. In this work, we demonstrate the possibility of using high speed machining with tungsten carbide tooling to significantly reduce machining times and minimize or eliminate hand polishing/grinding. Tool wear rates for the high speed machining of aluminum bronze are assessed using three metrics: mean force, flank wear depth, and surface finish. Workpiece surface finish and tool flank wear depth are assessed using a new replica block technique. Wear rates in carbide tools remained low over a wide range of surface speeds such that material removal rates in aluminum bronze were increased more than tenfold over current machining practices. Our findings support the idea that high speed machining to produce fine surface finishes through ball end milling with very closely spaced tool paths will be cost effective.