High hardness in a nanocrystalline Mg97Y2Zn1 alloy

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2011-09, Vol.528 (25-26), p.7494-7499
• Main Authors: Youssef, K.M., Wang, Y.B., Liao, X.Z., Mathaudhu, S.N., Kecskés, L.J., Zhu, Y.T., Koch, C.C.
• Format: Article
• Language: English
• Subjects: Alloy powders; Alloying elements; Applied sciences; Condensed matter: structure, mechanical and thermal properties; Crystal structure; Diffraction; Exact sciences and technology; Grain size; Hardness; Magnesium alloys, Mechanical alloying, Hardness; Magnesium base alloys; Mechanical and acoustical properties of condensed matter; Mechanical properties of nanoscale materials; Metal powders; Metals. Metallurgy; Nanocrystalline; Nanocrystals; Physics; Powder metallurgy. Composite materials; Production techniques
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2011.06.017

► Synthesis of nc (21nm) Mg97Y2Zn1 alloy using a modified mechanical alloying. ► Annealing at 573K increases the grain size to 28nm with a hardness of 2.4GPa. ► This is the highest value for hardness yet reported for a Mg-base (>95% Mg) alloy. ► The excellent strength of this alloy is discussed throughout the article. A nanocrystalline Mg97Y2Zn1 alloy was prepared with an average grain size of 21nm by mechanical alloying of elemental powders. The structure of the alloy was characterized by X-ray diffraction and transmission electron microscopy. The hardness of the alloy as-milled for 8h at room temperature was 2.1GPa. After compaction and annealing at 573K, the average grain size slightly increases to 28nm with an increase in hardness to 2.4GPa. These are the highest values for hardness yet reported for a crystalline Mg-based (>95% Mg) alloy. Possible factors leading to this high strength are discussed.