(上海交通大學(xué)鑄造研究所, 上海 200030
*西北工業(yè)大學(xué)凝固技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室, 西安 710072)
摘 要: 在自制的單晶連鑄設(shè)備上，通過(guò)各工藝參數(shù)合理匹配，成功地制備出了表面光潔、直徑8mm、長(zhǎng)8～10m的銅單晶鑄棒。通過(guò)理論分析和實(shí)驗(yàn)驗(yàn)證發(fā)現(xiàn)銅單晶連鑄時(shí)固液界面位于鑄型內(nèi)，并呈凸出形狀。鑄型溫度、連鑄速度和冷卻距離對(duì)固液界面的位置有很大的影響，其各工藝參數(shù)合理匹配，可使固液界面位置位于離鑄型出口端2～3mm ；并且當(dāng)連鑄速度大于40mm/min時(shí)，固液界面的形狀由凸變凹。當(dāng)鑄型溫度逐漸降低(低于銅熔點(diǎn)溫度)時(shí)，鑄棒表面由粗糙變?yōu)槔瓊踔脸霈F(xiàn)嚴(yán)重的拉裂；而隨著連鑄速度的增加，形成鑄棒表面拉傷(低溫時(shí))和條紋狀溝槽(高溫時(shí))。鑄棒內(nèi)的雜晶是由于鑄型溫度低于銅的熔點(diǎn)(1 083℃)和連鑄速度增加所致。當(dāng)連鑄速度大于40mm/min時(shí)，形成定向凝固的柱狀晶鑄棒。
關(guān)鍵字: 銅單晶 連續(xù)鑄造 工藝參數(shù) 固液界面
（Shanghai Jiao Tong University, Shanghai 200030, P. R. China
State Key Laboratory of Solidification Processing,
Northwestern Polytechnical University, Xi'an 710072, P. R. China）
Abstract:Single crystal copper rod, 8 mm in diameter and 8～10m in length with mirror-smooth surface has been obtained by using a self-made equipment under rational match of technological parameters. The solid-liquid interface is a convex shape and located in the inside of the mould during the continuous casting. It has been found that the mould temperature, the casting speed and the mould-cooler distance have effects on the solid-liquid interface position. The solid-liquid interface can be located at the inside of the mould extending 2～3mm from the mould exit under rational match of technological parameters, and at a casting speed above 40mm/min the shape of solid-liquid interface turns from convex shape to concave shape. When the mould temperature is less than 1083℃, which is the temperature of copper melting point, the surface appearance of the cast rod turns from rough surface to streaked surface, even forms cracked surface by drawing. With increasing casting speed, crack pits (low temperature) and ripple marks (high temperature) on the cast rods are formed. Stray crystals (equiaxed grains and columnar grains)in surface of the rod is formed because of lower mould temperature ( 1083 ℃) at location of the solidification front and increment of casting speed. At casting speed above 40mm/min, the rod contains unidirectional subtexture and occasional stray crystals.
Key words: single crystal copper; continuous casting ; solid-liquid interface; technological parameter
