Effect of the Supercooled Liquid Region on Al_(85)Ni_7Gd_8 Metallic Glass Crystallization Products

摘要

The effect of the supercooled liquid region on the primary crystallization of Al_(85)Ni_7Gd_8 metallic glass, which exhibits a clear glass transition before its primary crystallization, was evaluated systematically under different annealing conditions, including isothermal annealing at different temperatures and non-isothermal annealing employing different heating rates. It was found that isothermal annealing within the supercooled liquid region and non-isothermal annealing at small heating rates (≤ 5 °C/min) result in the co-precipitation of fcc-Al and Al compound(s). When isothermal annealing is done at temperatures where partial crystallization is involved, or non-isothermal annealing is carried out at a larger heating rate, the primary crystallization product is a single phase of fcc-Al. The effect of the supercooled liquid region on the crystallization product is discussed in detail.