An investigation was carried out to study the effect of heat treatment parameters on the structure and mechanical properties of aluminium bronze (Cu-10% wt. Al). The heat treatment parameters investigated were solutionizing temperature (800 and 900°C) and soaking time (0.5, 1, 2 and 3hrs). The alloy samples were produced using permanent die casting technique. Standard specimens were prepared from the as-cast and heat treated samples for tensile, hardness and impact strength tests as well as microstructural analysis according to standard. The samples were solutionized at temperature of 800°C and 900°C for 0.5, 1, 2 and 3hrs respectively and quenched in brine. The tensile, hardness and impact strength test were conducted using JPL tensile strength tester (Model: 130812), dynamic hardness tester and impact testing machine (U1820) respectively. The alloy microstructures were studied using an optical metallurgical microscope (Model: L2003A) and scanning electron microscopy (SEM). Microstructural analysis result indicated sparse distribution of coarse needle-like α+γ₂ precipitates in the as-cast specimen and presence of fine pearlite (α + γ₂) in a matrix of α dominance in the heat treated specimens. The presence of coarse intermetallic compounds (β`- phase) was revealed as the soaking time increased at high solutionizing temperature (900°C). The obtained results indicated that heat treatment significantly improved all the tested mechanical properties. Maximum percentage elongation was obtained in the specimens solutionized at 800°C for 3hrs and quenched in brine with %E of 73.1%. The specimen solutionized at 900°C for 0.5hr gave the maximum hardness of 513MPa. The ultimate tensile strength of aluminium bronze in as-cast condition increased from 240MPa to 609MPa when the alloy was solutionized at 900°C for 0.5hr. The heat treated alloy also demonstrated impact strength of 106J at solutionizing temperature of 800°C for 0.5hr.

Solutionizing Temperature, Soaking Time, Quenching Media, Heat Treatment, Properties