The Investigation of gas formation and gas removal techniques at casting of aluminium alloys

VII ABSTRACT In this paper, formation of gas porosity, one of the most comman faults seen in aluminium casting parts, is examined and the reasons of this is examined. Gas porosity affects not only mechanical properties, but also machinability and surface quality of aluminium casting parts. This unwanted casting fault is known to be especially depend on large amount of hydrogen in melt. In this paper, hydrogen, nowadays- which is used frequently and is the most factor effecting aluminium metal in liquid quality is. examined; measurement and detection methods are described. Herein, it has clearly been established that hydrogen is a danger for aluminium and with a cautious application the aluminium amount can be decreased to 0.15 ml / 100 gr. Keywords: Porosity, degassing, hydrogen, aluminium, surface quality.