Experimental Investigation of the Mg-Nd-Zn Isothermal Section at 300 °C

Metals

Ahmad Mostafa¹  Mamoun Medraj¹ 

[1] Department of Mechanical and Industrial Engineering, Concordia University, 1455 de Maisonneuve Blvd. West, Montreal, QC H3G 1M8, Canada; E-Mail:

关键词: Mg-Nd-Zn system;    diffusion couples;    experimental investigation;    ternary phase diagram;   

DOI  :  10.3390/met5010084

来源: mdpi

【 摘 要 】

The Mg-Nd-Zn isothermal section at 300 °C was established in the full composition range using diffusion couples and equilibrated key alloys. Microstructural characterization was carried out using WDS, XRD, and metallographic methods. The homogeneity ranges of the binary and ternary compounds were determined by WDS analysis. Six ternary compounds were observed in the Mg-Nd-Zn system at 300 °C. These are: τ₁ (Nd₅Mg_21+xZn_45−x; 0 ≤ x ≤ 4), τ₂ (Nd₅Mg_3+yZn_25−y; 0 ≤ y ≤ 1), τ₃ (NdMg_1+zZn_2−z; 0 ≤ z ≤ 0.44), τ₄ (Mg₄₀Nd₅Zn₅₅), τ₅ (Mg_22–23.5Nd_15.5–17.5Zn_59.1–61.8), and τ₆ (Nd₂(Mg,Zn)₂₃). τ₅ was found to have a homogeneity range of 22.0–23.5 atom % Mg, 15.5–17.6 atom % Nd and 59.1–61.8 atom % Zn and τ₆ was found to have 54.1–61.3 atom % Mg at a constant Nd of 8.0 atom %. The ternary solubility of Zn in Mg-Nd compounds was found to increase with the decrease in Mg concentration. Accordingly, (Mg₄₁Nd₅) was found to have an extended solubility of 3.1 atom % Zn, whereas (Mg₃Nd) was found to have 30.0 atom % Zn. MgNd was found to have a complete substitution of Mg by Zn. The maximum solid solubility of Zn in α-Mg was measured as 4.8 atom % Zn.

【 授权许可】

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