The effect of retrogression and re-ageing on the ductile fracture toughness of Al-Zn-Mg alloys containing different dispersoid phases

Uguz A., Martin J.

JOURNAL OF MATERIALS SCIENCE, vol.30, no.23, pp.5923-5926, 1995 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 30 Issue: 23
  • Publication Date: 1995
  • Doi Number: 10.1007/bf01151506
  • Journal Name: JOURNAL OF MATERIALS SCIENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.5923-5926
  • Bursa Uludag University Affiliated: Yes

Abstract

The effects of an incoherent and of a semi-coherent dispersoid phase upon the fracture toughness of a 7000-series AlZnMg alloys has been investigated. Standard crack opening displacement tests were successfully applied, the crack propagation being shown to be predominantly intergranular. The presence of manganese bearing incoherent dispersoids lowers the fracture toughness due to their effect of promoting microvoid formation. Retrogression and re-ageing led to a coarsening of the grain-boundary phases, but because the surface-to-surface separation of these particles remained approximately constant, there was no effect of this treatment, at constant yield stress, upon the fracture toughness. The toughness was only enhanced in the system (CZH) where retrogression and re-ageing led to a reduced yield stress.