Investigations on the influence of mechanical behaviour of copper aluminium nickel powder compacts processed through powder metallurgy

Abstract

Optimization is proved proficiency method, which is used for finding required process conditions to give the maximum or minimum value of the function. A new metal based alloy with a defined composition of Copper (84%) Aluminium (12%) Nickel (4%) is proposed. The powder has synthesized by a powder metallurgy process for the production of near net-shaped components through mechanical alloying. It is more complex to attain the properties in the making of materials for marine applications. The main objective of this study was to obtain an alloy compact with high density and hardness and consider a set of optimal process parameters like sintering temperature, holding time and compaction pressure. The alloy has a set of desired properties to suit the needs of the marine applications, porous material filters and electric friction equipments. The combination of Cu–Al–Ni offered in marine applications like rotary hydraulic actuator, hydraulic tube due to high mechanical strength, good corrosion resistance. Copper, Aluminium and Nickel powders are mixed by ball milling equipment and compacted at pressures 550, 590 and 630 MPa using Universal Testing Machine (UTM). These compact specimens have been sintered in an electric muffle furnace at temperatures 640, 695 and 750 °C at different holding times of 30, 60 and 90 min. The L9 orthogonal array was designed with the combination of input factors and their levels. The experiments were conducted at each level to measure the maximum hardness and density. Grey Relational Analysis was applied to find the optimum input parameter configuration. ANOVA was adopted to determine the level of significance of input factors. Confirmatory experiments were done to verify the optimal results.