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

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 60 h, the crystallite size of the matrix Mg in MgxTi100 − x (x = 95, 90, 85) composite powders was refined to 105 nm, 84 nm, and 76 nm, respectively. Meanwhile, the average size of the dispersed Ti particles in MgxTi100 − x (x = 90) composite powders was refined to about 1 μm. 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 60 h-milled MgxTi100 − x (x = 95, 90, 85) composite powders, the solid solubility of Ti in Mg was estimated to be 0.56 at.%, 1.32 at.% and 2.35 at.%, respectively.