Synthesis of nanocrystalline Mg-based Mg–Ti composite powders by mechanical milling

Abstract

The method of mechanical milling was applied to synthesize nanocrystalline MgxTi100−x (x=95, 90, 85) composite powders. The results reveal that mechanical milling is an effective method for preparing Mg–Ti composite powders, which consist of nanocrystalline Mg matrix and fine dispersed Ti particles. Moreover, the microstructure evolution and morphology of the as-milled powders were observed, and the corresponding mechanisms were also discussed. After milling for 60h, the crystallite size of the matrix Mg in MgxTi100−x (x=95, 90, 85) composite powders was refined to 105nm, 84nm, and 76nm, respectively. Meanwhile, the average size of the dispersed Ti particles in MgxTi100−x (x=90) composite powders was refined to about 1μm. Based on the XRD data, the solid solubility of Ti in Mg was calculated by using the Vegard's law. For all these Mg–Ti composite powders, the solid solubility of Ti in Mg seemed to be closely related with the milling time and the content of Ti. In the 60h-milled MgxTi100−x (x=95, 90, 85) composite powders, the solid solubility of Ti in Mg was estimated to be 0.56at.%, 1.32at.% and 2.35at.%, respectively.