Machinability of hypereutectic cast Al–Si alloys processed by SSM processing technique

Abstract

Experimental investigation carried out on the machinability studies to determine the influence of semi-solid metal processing and modification on hypereutectic Al–20Si–0.5Mg–1.2Fe-based alloy produced by conventional cast and semi-solid metal processing technique (mechanical stirring) and modified with iron correctors (Be and Cd) has been presented in this paper. The alloys under investigation were prepared by controlling melt using an induction melting furnace. Stirring of semi-solid metal takes place at constant cooling conditions from liquidus temperature at a constant stirring speed of 400 rpm. To determine the machining performance characteristics an orthogonal array, signal-to-noise ratio and statistical tool analysis of variance were jointly used during experimentation. A CNC lathe was used to conduct experiments in dry condition and coated carbide inserts were used as tool inserts. Machining variables like cutting velocity, approaching angle, feed rate and depth of cut, which can be considered as process parameters, are taken into account. The combined effect of modification and semi-solid metal processing has a significant effect on the machining characteristics, which was concluded from study. The modified alloy processed by semi-solid metal processing technique exhibits better machinability conditions when compared with the conventional cast. The feed rate has more effect on machining behaviour.