An Investigation of TIG Welding of AZ31 Magnesium Alloy Sheets


DEMİR B., Durgutlu A.

MATERIALS TESTING, vol.56, no.10, pp.847-851, 2014 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 56 Issue: 10
  • Publication Date: 2014
  • Doi Number: 10.3139/120.110635
  • Journal Name: MATERIALS TESTING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.847-851
  • Gazi University Affiliated: Yes

Abstract

In this study, butt welding of commercial AZ31 magnesium alloy sheets has been investigated by using the tungsten inert gas welding process with alternating and pulsed current. Magnesium alloy welding, although well developed and understood, can present some problems, such as porosity, hot cracking, oxide formation, etc.. Samples of the welded parts have been examined by optic microscopy and mechanic tests. Results showed that porosities and homogeneous micro size oxides were rarely found. Orientation of the weld microstructure in direction of the heat transfer were also rarely observed and equiaxed grain morphology was the dominant grain structure as in the base metals. In addition, fusion zone and HAZ of the welded samples have generally shown twins. This seems to be a very dominant grain type particularly in pulsed samples. Hot cracking was not observed in any samples. Results of mechanical tests showed that pulsed current seems to generate more favorable higher mechanical properties of weld joints than alternating current for magnesium alloys.