Machining of functionally graded Ti6Al4V/ WC produced by directed energy deposition

In this study, machining of functionally graded Ti6Al4V/ WC components consisting of a metal matrix composite (MMC) region and a single alloy region produced via direct energy deposition using commercially available tooling is explored. The influence of post processing on surface integrity is investigated and reported. The effect of material variation on cutting forces and tool response along the component is also analysed and reported. Cutting forces within the MMC region are found to increase by as much as 40% which has been subsequently related to the periodic changes in microstructure generated by the layer by layer build strategy. Tool wear mechanisms are investigated and the influence of material pull out on surface integrity of both MMC and single material regions is explored. This study provides an insight into how the layer building strategies, particularly with multiple materials and the resulting variation in microstructure influences the machining of resulting components.