Synthesis and Characterization of NanocrystallineMg-7.4%Al Powders Produced by Mechanical Alloying

Metals

Anil Kumar Chaubey¹  Sergio Scudino¹  Mohsen Samadi Khoshkhoo¹  Konda G. Prashanth¹  Nilay Krishna Mukhopadhyay³  Barada Kanta Mishra² 

[1] IFW Dresden, Institut für Komplexe Materialien, Postfach 270116, DresdenD-01171, Germany; E-Mails:;Institute of Minerals and Materials Technology (IMMT) Bhubaneswar-751013, India; E-Mails:;Department of Metallurgical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi-221005, India; E-Mail:

关键词: mechanical alloying;    nanocrystalline;    hardness;    particle size;    morphology;   

DOI  :  10.3390/met3010058

来源: mdpi

【 摘 要 】

Nanocrystalline Mg-7.4%Al powder was prepared by mechanical alloying using a high-energy mill. The evolution of the various phases and their microstructure, including size and morphology of the powder particles in the course of milling and during subsequent annealing, were investigated in detail. Room temperature milling leads to a rather heterogeneous microstructure consisting of two distinct regions: Al-free Mg cores and Mg-Al intermixed areas. As a result, the material is mechanically heterogeneous with the Mg cores displaying low hardness (40–50 HV) and the Mg-Al intermixed regions showing high hardness of about 170 HV. The Mg cores disappear and the microstructure becomes (also mechanically) homogeneous after subsequent cryo-milling. Rietveld structure refinement reveals that the crystallite size of the milled powders decreases with increasing the milling time reaching a minimum value of about 30 nm. This is corroborated by transmission electron microscopy confirming an average grain size of ~25 nm.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.