以快速凝固霧化法與粉末冶金製作Mg-Cu-Gd金屬玻璃塊材及其性質探討

Abstract

The Mg-Cu-Gd metallic glass powders was synthesized by the RSA (Rapid-Solidifying Atomization), a rapid solidification process. A container is designed for keep the powders pure form other materials in chamber, liquid nitrogen is injected into the container for reach the cooling rate to get amorphous structure, this part occupy the most time so far because of many problems to conquer, the best collection of powders now is 63%. The average size of spray-formed Mg-Cu-Gd metallic glass powder is 40~60 μm. The degree of crystallization and structure was determined by X-Ray Diffraction analyses, which shows amorphous structure. Differential Scanning Calorimeter analyses were performed to establish the glass transition and crystallization temperatures of the spray-formed Mg-Cu-Gd metallic glass powders. Isothermal DSC was also performed to determine the incubation times at various temperatures and its activation energy. The GFA (Glass Forming Ability) was determined with various glass forming criteria such as Trg and γ. Micro-TA is used to proof the correct of DSC and observe the surface of powders after the heating and crystallization. Microstructures and chemical compositions were characterized and analyzed by SEM and EDS, which has composition of Mg66.2Cu24.3Gd9.5. MHV hardnesses at different locations were measured by micro-Vickers hardness tester. The Mg66.2Cu24.3Gd9.5 metallic glass powders were hot pressed to consolidate, the extrusion with extrusion ratio 9 and 36 were followed. To discuss the influence of pressure and extrusion ratio. And compression test at room temperature were tested to get compressive strength.