Effects of Heat Treatment on Microstructure and Mechanical Properties of an ECAPed Al–Zn–Mg–Cu Alloy. Issue 9 (30th May 2018)

• Record Type: Journal Article
• Authors: Li, Jinghui; Li, Fuguo; Ma, Xinkai; Li, Jiang; Liang, Shan; Zhang, Long
• Is Part Of: Advanced engineering materials. Volume 20:Issue 9(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-05-30
• Subjects: aluminum alloy -- heat treatment -- mechanical property -- microstructure -- severe plastic deformation; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201701155
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : Equal‐channel angular pressing (ECAP) has a considerable advantage in the preparation of bulk fine‐grained alloys. To investigate the effect of solid solution treatment (SST) on the microstructure and mechanic properties of an Al–Zn–Mg–Cu alloy after ECAP, a comparative study is conducted using experimental techniques. It is shown that ECAP processing introduces a strong grain refinement, while the SST induces precipitation of skeleton‐like second phases distributed discontinuously at the grain boundary and needle‐like second phases in the grain. In addition, SST can also improve significantly the fractions of both high angle grain boundaries and recrystallization. The {110}<001> texture is introduced and the polar density is reduced during SST. Microstructural evolution involves three typical characteristics, namely, shear bands, substructure, and precipitates. The corresponding mechanism of microstructure evolution is proposed, considering the effect of dislocations, precipitates, and grain boundaries. After SST, the improvement of strength and hardness is not obvious, but significant in plasticity by 33.3%. Different strengthening mechanisms are also examined during ECAP and subsequent SST. Abstract : ECAP is used to prepare a ultrafine‐grained aluminum alloy and the effect of solid solution treatment on the microstructure is observed by OM, EBSD and TEM, and the corresponding mechanism is proposed. The mechanical properties are obtained using microhardness and tensile tests.