(北京科技大學(xué) 材料科學(xué)與工程學(xué)院，北京100083)
摘 要: 采用多彎道蛇形管澆注技術(shù)制備半固態(tài)A356鋁合金漿料。結(jié)果表明：在澆注溫度為640~680 ℃的條件下，當(dāng)彎道數(shù)量為3且直徑為20 mm時(shí)，可獲得形狀因子F為0.72~0.85和晶粒直徑D為55~75 μm的半固態(tài)漿料；當(dāng)彎道數(shù)量為5且直徑為20 mm時(shí)，可獲得形狀因子F為0.86~0.92和晶粒直徑D為44~58 μm的半固態(tài)漿料；當(dāng)彎道數(shù)量為5且直徑為25 mm時(shí)，可獲得形狀因子F為0.76~0.90和晶粒直徑D為48~68 μm的半固態(tài)漿料。彎道數(shù)量增加或彎道直徑減小，可以改善初生α(Al)晶粒的形貌和尺寸。彎道內(nèi)的合金熔體具有“自攪拌”的作用，可使初生晶核逐漸演變?yōu)榍蛐位蚪蛐尉Я！?/span>
關(guān)鍵字: 半固態(tài); A356鋁合金; 多彎道蛇形管; 初生α(Al); 微觀組織
serpentine pipe with multiple curves casting
（School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:Using serpentine pipe with multiple curves casting process, semi-solid A356 Al-alloy slurry was prepared. The results show that, at pouring temperatures of 640−680 ℃, when the number of the curves is 3 and their diameters are 20 mm, the semi-solid A356 Al-alloy slurry with shape factor of 0.72−0.85 and grain diameter of 55−75 μm can be prepared. When the number of the curves is 5 and their diameters are 20 mm, the semi-solid A356 Al-alloy slurry with shape factor of 0.86−0.92 and grain diameter of 44−58 μm can be prepared. When the number of the curves is 5 and their diameters are 25 mm, the semi-solid A356 Al-alloy slurry with shape factor of 0.76−0.90 and grain diameter of 48−68 μm can be prepared. With increasing the number of the curves or decreasing their diameters, the morphology and size of the primary α(Al) grains will be improved. The alloy melt has the effect of “self-stirring” in the serpentine curve, which can make the primary nuclei gradually evolve into spherical and near-spherical grains.
Key words: semi-solid; A356 Al-alloy; serpentine pipe with multiple curves; primary α(Al); microstructure
