Direct analysis of gases in a blow-hole in a cast pure copper by use of a newly made apparatus with a mass spectrometer

摘要

It is important to improve quality of cast metals such as copper, aluminum and their alloys by controlling of its defects. This study was carried out to analyze gas constituents directly in a blowhole of a cast pure copper by use of a newly developed apparatus. The apparatus is composed of a vacuum chamber and a double convergent mass spectrometer. A specimen with blowholes was first examined by X - ray methods to determine the location of a large blowhole and then the specimen was cut, polished so that one can make a hole through the large blowhole with no difficulty in the apparatus. After the specimen was set in the vacuum chamber, a weight attached with a wolfram needle was dropped with a guide to open the blowhole. This apparatus revealed that a main gas in a large blowhole in pure copper is water vapor. The developed method was judged to be useful based on the results of qualitative gas analysis.