The Study on Amorphization of Zr55Al10Ni5Cu30 Alloy Sheet by Centrifugal Casting Method

• Main Authors: Chieh Meng, 蒙捷
• Other Authors: 陳適範
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/t5w8zs

碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 99 === In the modern casting methods, centrifugal casting because of it''s larger centrifugal force could obtain closer finer structure, and be made wider and thinner cross-section than other casting methods. Zr55Al10Ni5Cu30 metallic glasses have good glass forming ability, high thermal stability of the supercooled liquid region and other characteristics. Therefore, we hope to combine these advantages and characteristics, make a larger volume of metallic glass. This study is prepared the sheet of Zr55Al10Ni5Cu30 alloy by centrifugal casting, discussion this casting method to make larger amorphous materials or not, and research its micro-structure, glass-forming ability, thermal properties and mechanical properties. The sheet of Zr55Al10Ni5Cu30 alloy by X-ray diffraction analysis shows that broad diffraction peaks with a few characteristic Bragg peaks, indicating the structure of specimen are amorphous base with a few precipitation of crystal phase. The result of XRD shows that crystallization in Zr55Al10Ni5Cu30 alloy include Ni7Zr2, Cu10Zr7 and ZrAl. By DSC measurements that first crystallization temperature (Tx) is 482 ℃, supercooled liquid region (ΔTx) is 85.4℃,the most far away from the riser and the thinnest specimen has the best glass forming ability with glass transition temperature (Tg) is 401.4℃, ΔTx is 85.4℃. In the test of mechanical properties, located in the central region of the specimen has the best Vickers hardness value, about 520.8 Hv, because of the precipitation of crystallization is good at enhance the hardness, but after the net-structure appeared, hardness begin to decrease, about 491.5Hv.