Effect of La content and extrusion temperature on microstructure, texture and mechanical properties of Mg-Zn-Zr magnesium alloy

Küçük Resim Yok

Tarih

2018

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Elsevier Science Sa

Erişim Hakkı

info:eu-repo/semantics/closedAccess

Özet

The microstructure, texture and mechanical properties of Mg-6wt%Zn-0.5 wt%Zr (ZK60) alloys with different La contents (0, 0.5 and 1 wt%) were investigated. The alloys were produced by low-pressure die casting and extruded at 300 degrees C and 400 degrees C, following homogenization at 400 degrees C for 24 h. La addition to ZK60 alloy resulted in a formation of Mg-Zn-La ternary phase, generating a semi-continuous network structure in their as-cast state. After extrusion, secondary phases were broken into fine particles distributed along the extrusion direction. These fragmented particles led to a nucleation of new grains around them i.e. particle stimulated nucleation (PSN), and promoted dynamic recrystallization (DRX) during extrusion. Therefore, increasing La content led to an increase in DRX fraction. Higher extrusion temperature resulted in larger DRXed grains and higher DRX fraction. The basal texture intensity was also decreased with increasing La addition and extrusion temperature by PSN mechanism and solute atoms of La. The ZK60-1La alloy extruded at 300 degrees C showed a superior yield strength of 311 MPa and ultimate tensile strength of 360 MPa as a result of significant grain refinement and dispersion strengthening. Increasing extrusion temperature resulted in a decrease in yield and ultimate tensile strengths and increase in ductility. (C) 2018 Elsevier B.V. All rights reserved.

Açıklama

Anahtar Kelimeler

ZK60 magnesium alloys, La modification, Extrusion, Microstructure, Mechanical properties

Kaynak

Materials Chemistry and Physics

WoS Q Değeri

Q2

Scopus Q Değeri

Q1

Cilt

214

Sayı

Künye