Time–temperature superposition for foaming kinetics of Al-alloy foams

Applicability of time–temperature superposition principle to the foaming kinetics of aluminum (Al)-alloy foams produced by powder metallurgical method was investigated. Foaming kinetics above melting temperatures of Al–Si–Cu–Mg foams was studied. The expansion data at various furnace temperatures were collected. Well-known superposition parameters such as Larson-Miller, Orr-Sherby-Dorn, Goldhoff-Sherby and Manson-Succop were established based on the linear iso-expansion lines in plots of log(heating time) versus furnace temperature and log(heating time) versus inverse furnace temperature. In order to study the expansion kinetics of the Al-alloy foams, the expansions were measured in terms of pore fraction using an image analyzer. Finally, the linear relationship between the porosity and the superposition parameters was established.