(東北大學(xué) 冶金與材料學(xué)院， 沈陽 110004)
摘 要: 利用SCR成形技術(shù)， 使液固反應(yīng)法獲得的Al-5Ti-0.25C合金在強(qiáng)剪切應(yīng)力場中凝固成形，制備了高細(xì)化活性的Al-Ti-C晶粒細(xì)化劑，對純Al細(xì)化時其晶粒尺寸小于80μm。 研究了SCR成形合金的微觀結(jié)構(gòu)及其形成機(jī)制。 結(jié)果表明： SCR成形過程中合金熔體受到強(qiáng)烈剪切與熱擾動作用，影響了自由晶TiC的遷移行為及TiAl3的溶解析出， 從而改變了Al-5Ti-0.25C合金的組織形態(tài)； TiC粒子呈彌散分布以及與TiAl3形成二重粒子均能顯著提高TiC粒子的形核能力。
關(guān)鍵字: SCR成形； Al-5Ti-0.25C合金；彌散分布； 二重粒子；形核能力
ZHAN Guo-chan, WEN Jing-lin
（School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China）
Abstract: The SCR(shear-cooling roll) technique was used to solidify dynamically and form directly from the melt of Al-5Ti-0.25C alloy to prepare Al-Ti-C grain refiners with high activity of refinement, with average grain size 80μm in refining pure aluminum. The microstructure of SCR formed alloy and its formation mechanism were studied experimentally. It is shown that the strong shearing and heat disturbance action of SCR forming process on alloy melt affect the behavior of migration of free crystal TiC and the dissolution and precipitation of TiAl3 and thus change the microstructural morphology of Al-5Ti-0.25C alloy. The dispersive distribution of TiC particles inside α(Al) and the formation of duplex particles of TiC particles with TiAl3 can improve significantly the capability of nucleation of TiC particles.
Key words: SCR forming; Al-5Ti-0.25C alloy; dispersive distribution; duplex particles; capability of nucleation
