Effects of Deformation Temperature and Alloying Content on the Deformation and Fracture Behaviours of α Cu-Zn, α Cu-Al Alloys

Abstract

Deformation and fracture behaviour of α Cu-Zn, α Cu-Al alloys were examined by micro-structural observations. The results are summarized as follows:
(1) The distribution of slip bands of 70/30 brass changes remarkably as the deformation temperature is raised. Though the straightness of slip bands does not change upto about 720 K, the distribution of them becomes coarser as the deformation temperature is raised at intermediate temperatures. Also, the deformation structure at high temperatures (above about 720 K) is characterized by subboundaries and recrystallization, however, free dislocations are observed in the regions surrounded by subboundaries.
(2) Though remarkable intergranular fractures are observed at the intermediate temperature range, the fractured surfaces show dimple patterns. Also, similar facet structures and dimple arrangements to those observed in α brass bicrystals are found even in α brass and α Cu-Al polycrystals.
(3) In high concentrations of alloys planar arrangements and pile ups of dislocations are observed, but cell structures are observed in low concentrations of alloys.
(4) All the structural observations correspond to the behaviour of deformation and fracture of the alloys reported in the preceding papers.