Effect of Y addition on microstructure and corrosion behavior of extruded Mg-Zn-Nd-Zr alloy

• 作者: Huseyin Zengin Yunus Turen
• 来源期刊: 镁合金学报(英文)
• 学科: 工学
• 关键词: ZK60 magnesium alloys Rare earth YTTRIUM EXTRUSION MICROSTRUCTURE Corrosion
• 年，卷（期）: 2020,（3）
• 页码范围: 640-653
• 页数: 14页
• 分类号: TG1

摘要

In this study,the effect of Y addition(0,0.5,1 and 2 wt%)on microstructure and corrosion properties of Mg-6Zn-0.5Zr-1 Nd(wt%)alloy was investigated.The alloys were produced by low-pressure die casting method and extruded at 300℃and 400℃after homogenization treatment at 400℃for 24 h.The results showed that the as-cast microstructure of the alloy with no Y addition consisted ofα-Mg,Mg-Zn binary and Mg-Zn-Nd ternary phases.With increasing Y additions,the average grain size showed a substantial decrease and two kinds of ternary Mg-Zn-Y ternary phases,designated as I-phase(Mg3Zn6Y)and W-phase(Mg3Zn3Y2)were formed.Homogenization treatment resulted in a partial dissolution of second phase particles.Extrusion process gave rise to a remarkable grain refinement due to the DRX mechanism.The extruded alloys with no Y addition exhibited poor corrosion resistance due to the strong micro galvanic coupling effect.Y additions up to 1 wt%improved the corrosion resistance due to the formation of finer grains,fine and uniform distribution of second phase particles and more stable oxide film.