Characterization of casting alloy Al 319 (Al-12Si-4Cu-0.1Mg), PROTON cylinder head

Abstract

The present study was undertaken to investigate the effect of metallurgical parameters on the hardness, microstructural characterization and porosity of heat-treated 319 alloys, with the aim of adjusting these parameters to produce castings of suitable hardness and porosity relating to the machinability of this alloy. The 319 alloys were examined in the heat-treated conditions, using different quenching media. The alloy being solution treated at 510°C for 8 h appeared to be the best solution heat treatment recommended for 319 alloys, and then quenched with different quenching media; water, oil, hot water and ice. Aging treatments were carried out at 158°C for 3 h, followed by air cooling, to determine the hardness. Hardness measurements were carried out using a Rockwell hardness tester. Hardness peak can be observed for water quenching sample after the ageing treatment. The microstructure of the alloy not much varies from a non heattreated alloy. After quenching the only sample that get a vary microstructure is the one that has been quenched using hot water. For this sample the intermetallic precipitations look finer than others. When ageing process ended the microstructure of all sample looked the same. The effect of porosity of 319 aluminum alloys was studied, where the porosity characteristics were examined using a simple experiment. Porosity is decrease after the alloy go through a heat treatment process.