(大連理工大學(xué) 材料科學(xué)與工程學(xué)院，大連 116024)
摘 要: 采用ProCast軟件研究了(Cu47Zr45Al8)98.5Y1.5塊體非晶板材水平連鑄過程中的溫度場(chǎng)分布和凝固界面變化。結(jié)果表明：熔體在中間包內(nèi)的充型時(shí)間為22 s，保溫時(shí)間不應(yīng)超過55 s。鑄坯的冷卻過程分為兩個(gè)階段，第一階段當(dāng)拉坯速度為1 mm/s時(shí)，熔體在石墨內(nèi)凝殼，冷卻速率小于10 K/s，不利于形成塊體非晶；第二階段鑄坯的熱量直接傳遞給銅模，冷卻速率大于40 K/s。提高拉速及增大過熱度有利于凝固界面前移，熔體在液相線溫度Tl時(shí)的冷卻速率大于40 K/s，滿足Cu基非晶的臨界冷卻速率(20 K/s)。改善模具結(jié)構(gòu)，縮短石墨端嵌入模具長(zhǎng)度，熔體由Tl冷卻至玻璃化轉(zhuǎn)變溫度Tg所需的時(shí)間減少，有利于獲得非晶組織。實(shí)驗(yàn)驗(yàn)證發(fā)現(xiàn)，拉坯參數(shù)為拉坯速度2 mm/s、過熱度80 K、石墨嵌入深度20 mm時(shí)，可獲得具有明亮金屬光澤的非晶合金板材。
關(guān)鍵字: 水平連鑄；數(shù)值模擬；復(fù)合模具；冷卻速率；凝固界面
（School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China）
Abstract:In this paper, the distributions of temperature fields and solidification interface in horizontal continuous casting of (Cu47Zr45Al8)98.5Y1.5 bulk metallic glasses (BMGs) slab were studied by ProCast. The results show that the mold filling time in the tundish is 22 s, and the holding time in the tundish should not exceed 55 s. The slab undergoes two cooling stages. In the first stage, the melt solidifies in the graphite passageway, the drawing speed is 1 mm/s and the cooling rate is less than 10 K/s. In the second stage, the heat of the slab is directly transferred to the copper, and the cooling rate is more than 50 K/s, which is sufficient for the critical cooling rate for CuZr based BMGs (20 K/s). The increase of drawing speed and superheat can promote the solidification interface to move along the casting direction, so that the melt can obtain a large cooling rate above 50 K/s near Tl. By improving the mold structure and shortening the embedding depth of the graphite, the time needed from Tl to Tg is reduced, which is conducive to obtaining amorphous microstructure. The experimental verification reveals that when the daring parameters are drawing speed of 2 mm/s, superheat of 80 K and embedded depth of 20mm, a BMGs slab with shiny metal luster can be obtained
Key words: horizontal continuous casting; numerical simulation; composite mould; cooling rate; solidification interface
