The Effect of Iron and Oxygen Additions on the Properties of Zr-Al-Cu-Ni Bulk Metallic Glass Forming Alloys

Abstract

ABSTRACTThe effect of iron and oxygen additions on the thermal stability of rapidly quenched amorphous Zr65Al7.5Cu17.5Ni10) was studied by x-ray diffraction and differential scanning calorimetry. With increasing Fe content the glass transition temperature Tg and the crystallization temperature Tx shift to higher temperatures. The increase is more significant for Tg than for Tx, resulting in a decrease of the supercooled liquid region with increasing Fe content. For oxygen additions Tx decreases with increasing oxygen content whereas Tg increases slightly, causing a decrease of the supercooled liquid region with increasing oxygen content. The results reveal that even minor iron or oxygen contaminations lead to drastic changes in the glass transition behavior and the crystallization mode. Large iron or oxygen contents lead to the formation of nanocrystalline microstructures instead of coarse-grained material.