No abstract

The strength of aluminum alloy decreases sharply with the increase of temperature. One of the major drawbacks of aluminum alloys is that it does not retain their mechanical properties at higher temperatures. To solve this problem, the high-temperature stability of the Al-Ce system is studied. The effect of alloying elements on the thermal stability of five different near eutectic Al-Ce based alloys, i.e., Al-12Ce, Al-12Ce-4Si, Al-12Ce-0.4Mg, Al-12Ce-4Si-0.4Mg and Al-12Ce-4Si-0.4Mg-0.25Sr alloys, were investigated. The alloys were heat treated at three different temperatures, i.e., 200 °C, 300 °C and 400 °C, to establish thermal stability. Binary Al-12Ce alloy consisting of α-Al and showed higher resistance to coarsening at all temperatures. The addition of Si helps retain the microstructure stability above 200 °C and the combined addition of Si and Mg increases the room and high-temperature strength up to 300 °C. The addition of Sr to quaternary alloy was not beneficial for enhancing thermal stability.

In the present investigation, the microstructure and tensile properties of Al–12Ce, Al–12Ce–4Si, and Al–12Ce–4Si–0.4Mg alloys (wt-%), fabricated by suction-casting (SC) and gravity-casting (GC) were compared. The SC alloys exhibited finer grains and a higher number of precipitates than the GC alloys. Addition of Si and Mg in Al–12Ce alloy improved the hardness substantially. Incorporation of 4Si and 0.4Mg enhanced the yield and tensile stress but reduced ductility in the SC alloys. The SC Al-12Ce-4Si-0.4Mg alloy illustrated the best hardness and tensile strength. The fracture behaviour of the SC Al–12Ce alloy changed from quasi-cleavage to complete cleavage fracture following the addition of 4Si and 0.4Mg.

The strength of aluminum alloy decreases sharply with the increase of temperature. One of the major drawbacks of aluminum alloys is that it does not retain their mechanical properties at higher temperatures. To solve this problem, the high-temperature stability of the Al-Ce system is studied. The effect of alloying elements on the thermal stability of five different near eutectic Al-Ce based alloys, i.e., Al-12Ce, Al-12Ce-4Si, Al-12Ce-0.4Mg, Al-12Ce-4Si-0.4Mg and Al-12Ce-4Si-0.4Mg-0.25Sr alloys, were investigated. The alloys were heat treated at three different temperatures, i.e., 200 °C, 300 °C and 400 °C, to establish thermal stability. Binary Al-12Ce alloy consisting of α-Al and showed higher resistance to coarsening at all temperatures. The addition of Si helps retain the microstructure stability above 200 °C and the combined addition of Si and Mg increases the room and high-temperature strength up to 300 °C. The addition of Sr to quaternary alloy was not beneficial for enhancing thermal stability.