(昆明理工大學(xué) 材料科學(xué)與工程學(xué)院，昆明 650093)
摘 要: 利用有限元方法對(duì)電子束冷床熔煉大規(guī)格TC4扁錠連續(xù)凝固過(guò)程溫度場(chǎng)進(jìn)行計(jì)算分析，研究不同鑄造工藝條件下熔池形貌特征以及固液界面曲率的變化，并且定量地給出固相線和液相線位置以及糊狀區(qū)深度的變化規(guī)律。結(jié)果表明：隨著澆注溫度的升高，TC4扁錠的液相線和固相線深度加深、寬度變寬，而固相線與液相線之間的糊狀區(qū)變窄；隨著拉錠速度的加快，熔池加深變寬，糊狀區(qū)逐漸變寬，溫度梯度變小，固相率逐漸減少；但拉錠速度對(duì)固液界面形貌的影響相對(duì)于澆注溫度的影響更為顯著，在本計(jì)算模擬條件下，拉錠速度應(yīng)控制在3.5×10-4 m/s以下。
關(guān)鍵字: 大規(guī)格TC4扁錠；連續(xù)凝固；澆注溫度；拉錠速度
（School of Materials Science and Engineering,
Kunming University of Science and Technology, Kunming 650093, China）
Abstract:The continuous solidification process of the large scale TC4 titanium alloy during electron beam cold hearth melting was computational analyzed by using finite element method in order to study the temperature field distribution, which focused on the feature of the molten pool and the change of curvature of solid-liquid interface at the different process conditions. In addition, it is quantitatively given that the relationship of the situation of solidus and liquidus and the depth of mushy zone with different process conditions. The results show that under the same pulling speed, the deepening and widening of the liquidus and solidus of the TC4 titanium alloy slab ingot are caused by increasing of pouring temperature. While with the increase of pouring temperature, the mushy zone between liquidus and solidus shallows. Under the same pouring temperature, the deepening and widening of the molten pool and the mushy zone, reducing of the temperature gradient and decreasing of the solid fraction are caused by increasing of pulling speed. However, the effect of pulling speed on the solid-liquid interface morphology is more remarkable than pouring temperature, the pulling speed should be controlled under 3.5×10-4 m/s in this computational condition.
Key words: large scale TC4 titanium alloy; continuous solidification casting; pouring temperature; pulling speed
