Synthesis of Mg-Cu-Gd amorphous alloy by mechanical alloying and its thermal stability
(1.Chongqing Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China
2.重庆市重庆大学镁合金国家工程研究中心)
2.重庆市重庆大学镁合金国家工程研究中心)
Abstract: Mg65Cu25Gd10 amorphous alloy powders were synthesized by mechanical alloying (MA). The most suitable process is that the milling velocity is 600 r/min and the mass ratio of ball to powder is 20？1, so the shortest forming time of the amorphous is about 40 h. The thermal stability of the powders was analyzed by differential scanning calorimetry (DSC). The glass transition temperature, (Tg), onset temperature of crystallization(Tx), width of supercooled liquid region, were determined to be 444.8, 531.1 and 86.3 K, respectively. Contrasting them with the parameters of samples produced by traditional copper-mold casting, it is found that the thermal stability of the former is better than that of the latter. At the same time, the crystallization kinetics of those amorphous powders was researched by Kissinger equation and the apparent activation energy at Tg and Tx was calculated.
Key words: Mg65Cn25Gd10 alloy; magnesium amorphous alloys; mechanical alloying; thermal stability; apparent activation energy