(1. 北京科技大學(xué) 材料科學(xué)與工程學(xué)院, 北京100083;
2. 內(nèi)蒙古工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院 ,
呼和浩特 010062)
摘 要: 在充分考慮半固態(tài)AlSi7Mg合金觸變充型過程中壓力和速度變化特征基礎(chǔ)上，建立耦合半固態(tài)表觀粘度的三維流場(chǎng)數(shù)學(xué)模型， 確定固定流量的入流邊界條件和約束滑動(dòng)型壁邊界條件以及保持入流溫度不變的初始條件， 并采用SOLA-VOF法對(duì)鋁合金件的觸變充型過程進(jìn)行了模擬計(jì)算。 結(jié)果表明, 由于半固態(tài)表觀粘度隨剪切速率增大而下降, 造成局部漿料充型速度的復(fù)雜變化， 從而使半固態(tài)合金呈現(xiàn)剪切變稀的觸變成形特點(diǎn)。 由于充型時(shí)間極短， 漿料在充型過程中降溫小于1℃。 剎車泵體模擬計(jì)算結(jié)果展示了模擬與實(shí)際成形結(jié)果的一致性。
關(guān)鍵字: 充型模擬; 表觀粘度; 半固態(tài); 邊界條件
ZHAO Ai-min1, ZHONG Xue-you1
（1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China；
2. School ofMaterials Science and Engineering,
InnerMongolia Polytechnic University,Huhehaote 010062, China）
Abstract:Based on the behavior characters of pressure and flow velocity during semi-solid AlSi7Mg slurry filling processes, a three dimensional model of slurry flow coupled with apparent viscosity was established. The filling simulation of the semi-solid forming process for semi-solid aluminum casting was investigated with the help of the SOLAVOF algorithm. And fixed volume of flow and sliding along wall were used for boundary conditions, slurry temperature was used for initiation condition. Results demonstrate that apparent viscosity decreases with the increase of shear rate, semi-solid alloy shows that shearing thinning thixotropy and its temperature differential is below 1℃ in the course of the filling.
Key words: filling simulation; apparent viscosity; semi-solid; boundary condition
