A new type of anti-phase boundaries in the T(Al20Cu2Mn3) phase and the pre-deformation effect on T phase precipitation. (December 2020)

• Record Type: Journal Article
• Authors: Chen, Y.Q.; Tang, Z.H.; Pan, S.P.; Liu, W.H.; Song, Y.F.; Liu, Y.; Zhu, B.W.; Zhou, W.; Shen, F.H.
• Is Part Of: Intermetallics. Volume 127(2020:Dec.)
• Publication Date: 2020-12
• Subjects: Al alloys -- T phase -- Interface -- Anti-phase boundaries -- Pre-deformation -- High-resolution transmission electron microscopy; Intermetallic compounds -- Metallography -- Periodicals; Metallic glasses -- Periodicals; Composés intermétalliques -- Métallographie -- Périodiques; 669.94
• DOI: 10.1016/j.intermet.2020.106977
• Languages: English
• ISSNs: 0966-9795

Abstract

Abstract: The anti-phase boundaries (APBs) in the T (Al20 Cu2 Mn3 ) phase and the interfaces of the T phase with an Al matrix were observed. The effects of pre-deformation on the precipitation behavior of T phase and hardening behavior of alloy were investigated by hardness measurement, mechanical tensile test, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Results show that two kinds of APBs exist in the T phase, i.e . {101}T and {301}T -type APBs. The first is commonly observed, while the latter is newly found and only coexists with the first to form a zig-zag shaped APB. Whatever its orientation relationships (ORs) with Al matrix and cross-section (CS) shape, the T phase always retains its interfaces constituted by {200}T, {101}T and {301}T planes. Pre-deformation increases the APBs in T phase and intensifies the irregularity of the CS shape of a T phase. Besides, it also promotes the nucleation and refines the size of the T phase during precipitation which enhances the mechanical properties of the alloy. Highlights: A new type of APB with slip displacement of 1/4 <301>T is found in the T-phase. The {301}T type APB coexists with {101}T type APB to form a zig-zag-shaped APB. The T-phase interfaces are always constituted by {200}T, {101}T, and {301}T planes. Pre-deformation increases APBs and causes a more irregular cross-section of T-phase. Pre-deformation promotes the nucleation rate and refines T-phase.