摘要
Effects of cooling rate on thermal expansion of Cu49Hf42Al9 metallic glass were studied. Five types of amorphous samples with different sizes were prepared in order to get a broad range of cooling rates （from 102 to 107 K/s）. The average thermal expansion coefficients （αaver） of as-quenched samples range from 6.14×10-6 to 9.20×10-6 K-1. When the temperature is below the glass transformation temperature （Tg）, αaver of as-quenched samples has a negative correlation with cooling rate; the values of αaver of annealed and crystallized samples are closed to each other. The results indicate that the amount and motion of free volume play important roles in thermal expansion of metallic glasses.
研究冷却速率对Cu49Hf42Al9金属玻璃热膨胀行为的影响。为了得到较大范围的冷却速率,制备了5种不同尺寸的非晶样品（冷却速率范围为102~107K/s）。淬火态样品的平均热膨胀系数（αaver）分布于6.14×10-6K-1至9.20×10-6K-1之间。在玻璃转变温度（Tg）以下时,淬火态样品的平均热膨胀系数（αaver）与冷却速率呈反比;退火态与晶态样品具有相似的平均热膨胀系数。结果表明,自由体积的数量和运动对于金属玻璃的热膨胀具有重要作用。
基金
Projects(50831003,50871062)supported by the National Natural Science Foundation of China
Project(Z2008F08)supported by the Natural Science Foundation of Shandong Province,China
