Abstract
Gas in aluminium and cast aluminium alloys, i.e. Silumin, Y alloy, and Lautal, was estimated by means of hot extraction porcess in vacuum.
It was found that the amount of gas in commercial aluminium was about 1.5 cc/100 grams and 2 or 3 times in aluminium alloys for casting.
The extracted gas is composed of 85_??_94% hydrogen and 4_??_8% CH4, CO and CO2 being almost absent.
Huge amount of gas in aluminium, which is frequently reported by different authors, is proved to be attributed to the surface contamination of the sample as is already pointed out by Steinhäuser.
A new method for obtaining the sample free from surface, contamination is proposed; the method consists in cutting out the sample with a clean saw and scraper, which are previously washed with benzene and alcohol and are heated by small gas flame.
