Optimisation of machining parameters for minimising cutting forces during machining of Al alloy SiC particle composites

Machining experiments on 7075 Al alloy/10 wt% SiC (particle size 10–20 µm) have been conducted based on response surface methodology (RSM). Sequential approach using face-centred central composite design is followed. Optimum cutting speed is to be in the range 144-210, to have minimum tangential force, feed force and radial force,, feed is to be in the range of 0.15–0.25 mm, depth of cut is to be 0.20 mm and nose radius 0.40 mm. Depth of cut is the leading contributor to the tangential force, whereas feed rate is the main contributor of the feed force. The quadratic model best describes the deviation of cutting force with main contribution of depth of cut and then contributions of interaction effect between feed and depth of cut, second-order (quadratic) effect of feed rate and interaction effect between speed and depth of cut. Suggested models of cutting forces sufficiently map within the limits of the cutting parameters. Optimum value parameters have been obtained at which cutting forces will be minimum and the performance and accuracy of machining will be improved.