Metallographic Examination of AA7075 Alloy Produced By Rheocasting


KILIÇLI V. , Uslu A. H. , Cifci M., AKAR N.

JOURNAL OF POLYTECHNIC-POLITEKNIK DERGISI, vol.20, no.3, pp.585-594, 2017 (Journal Indexed in ESCI) identifier

  • Publication Type: Article / Article
  • Volume: 20 Issue: 3
  • Publication Date: 2017
  • Doi Number: 10.2339/politeknik.339372
  • Title of Journal : JOURNAL OF POLYTECHNIC-POLITEKNIK DERGISI
  • Page Numbers: pp.585-594

Abstract

In this study, microstructure and casting defects were investigated metallographically in AA7075 alloy part produced by rheocasting. AA7075 Al alloy is one of the most widely used Al-Zn alloy in the industry was formed by the rheocasting method, which is one of the semi-solid metal forming process. Specimens produced by the swirled enthalpy equilibrium device (SEED) process were used in rheocasting. Experimental results showed that AA7075 could be formed by rheocasting. In rheocast AA7075 aluminum alloy, globular grains were formed rather than dendrite in the microstructure. It is understood that in the liquid-rich regions, microsegregation were caused hot tearing in AA7075 aluminum alloy produced by rheocast casting. According to radiographic examination, the presence of hot tearing and shrinkage in the center of specimens was determined. It was found that lower hardness values obtained in the edge regions of the specimens due to liquid segregation.