機械合金法合成鎂基非晶複合材料之研究

Synthesis of Mg-based amorphous composites by mechanical alloying technique

江瑋倫(Wel-Lun Chiang)

指導教授 ： 胡家榮

大同大學/工程學院/材料工程學系所/碩士(2010年)

摘要

真空熱壓成型的可行性，利用XRD、SEM及DSC觀察粉末在機械合金過程中的結晶結構、微觀組織與熱穩定性，研究結果經11小時機械合金化處理後，Mg-Cu-Ni系統的非晶質合金粉末具有寬廣過冷液態區，ΔT大約為43K；Mg-Cu-Ti系統的非晶質合金粉末不具有寬廣過冷液態區，添加Ni比添加Ti，更易形成非晶質相。將Mg-Cu-Ni系統的非晶質合金粉末進行真空熱壓成形，（Mg65Cu35）92Ni8在260℃，以1.2GPa的壓力下不持溫，可形成直徑10mm、厚度2mm的緻密非晶塊材，其孔隙率僅2.35％、微硬度達431Hv；隨著持溫時間增加，緻密度及微硬度都降低。

關鍵字

機械合金 ； 非晶質相 ； 鎂基合金 ； 真空熱壓

並列摘要

This study examined the amorphization behavior of Mg-based alloy powders synthesized by mechanically alloying and the feasibility of consolidation by vacuum hot pressing. The crystallization structure, microstructure and thermal stability during mechanical alloying of as-milled powder were investigated by X-ray diffraction, scanning electron microscopy and differential scanning calorimetry, respectively. After 11-hour milling, Mg-Cu-Ni system amorphous powders exhibited a wide supercooled liquid region of 43K before crystallization. As the results demonstrated, the small addition of Ni improved the glass forming ability(GFA) of Mg-based amorphous alloys, which is better then the small addition of Ti. The as-milled（Mg65Cu35）92Ni8 powders were consolidated at 260℃ under a pressure of 1.2GPa by hot pressing into disc compacts with a diameter and thickness of 10 and 1 mm, respectively. Its microhardness and porosity percentage are 431Hv and 2.35%, respectively. With increasing the isothermaltime, the density and microhardness of these alloys decrease.

並列關鍵字

Mechancial alloying ； Amorphous phase ； Mg-based

參考文獻

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