CAJ | 학술논문

采用铜模吸铸法制备出La62.0Al15.7(Cu0.5Ni0.5)22.3大块金属玻璃,经高压处理后,用X射线衍射仪(XRD)和示差扫描量热计(DSC)对非晶的结构驰豫和晶化过程进行了研究.结果表明,非晶玻璃转变温度和第一晶化温度随着压力的增加,其先增加后减小,极大值出现在4.0 GPa的压力.这种现象归因于经过高压处理后玻璃转变温度区焓的变化,而焓的变化由基体缺陷激活体积引起自由体积变化所导致.此外,高压处理还影响玻璃的结晶过程.
채용동모흡주법제비출La62.0Al15.7(Cu0.5Ni0.5)22.3대괴금속파리,경고압처리후,용X사선연사의(XRD)화시차소묘량열계(DSC)대비정적결구치예화정화과정진행료연구.결과표명,비정파리전변온도화제일정화온도수착압력적증가,기선증가후감소,겁대치출현재4.0 GPa적압력.저충현상귀인우경과고압처리후파리전변온도구함적변화,이함적변화유기체결함격활체적인기자유체적변화소도치.차외,고압처리환영향파리적결정과정.
s In this study, La62.0Al15.7(Cu0.5Ni0.5)22.3bulk metallic glasses (BMGs) were prepared by copper mold casting method, and the effects of the pressure treatment up to 5.0 GPa at room temperature on structural relaxation were investigated by X-ray diffrac-tion (XRD) and differential scanning calorimeter (DSC). The results showed that structural relaxation occurred with changes of the glass transition temperature (Tg) and the onset of primary crystallization (Tx1). Both increased with increasing of applied pressure up to 4.0 GPa beyond which they decreased. The enthalpy changed at the glass transition temperature regime showed that the reduction of the flee volume caused by the HP treatment can be interpreted by the activation volumes of the flow defects. Furthermore, the HP treatment also influenced the crystallization sequence of the BMG.