CAJ | 학술논문

采用液-液混合受控扩散凝固技术(CDS)制备过共晶Al-20%Si 合金，研究高硅合金温度对目标合金组织中初生硅的影响及混合过程中初生硅细化的热力学条件。结果表明：采用液-液混合制备过共晶铝硅合金，可以细化初生硅，初生硅平均尺寸可达到37μm；但随着高硅合金温度的升高，初生硅的平均尺寸增加，板条状和五瓣星状初生硅也增多，当高硅温度超过790℃时，初生硅细化效果丧失。分析得出，只有当混合前两种合金吉布斯自由能的加权平均值小于混合后目标合金在液相线的吉布斯自由能( final,liquidusmG =-39.3366 kJ)时，初生硅才能得到明显的细化。
채용액-액혼합수공확산응고기술(CDS)제비과공정Al-20%Si 합금，연구고규합금온도대목표합금조직중초생규적영향급혼합과정중초생규세화적열역학조건。결과표명：채용액-액혼합제비과공정려규합금，가이세화초생규，초생규평균척촌가체도37μm；단수착고규합금온도적승고，초생규적평균척촌증가，판조상화오판성상초생규야증다，당고규온도초과790℃시，초생규세화효과상실。분석득출，지유당혼합전량충합금길포사자유능적가권평균치소우혼합후목표합금재액상선적길포사자유능( final,liquidusmG =-39.3366 kJ)시，초생규재능득도명현적세화。
The hypereutectic Al-20%Si alloy was fabricated by liquid-liquid mixing of controlled diffusion solidification (CDS), and the effect of temperature of high silicon alloy on the microstructure of primary silicon phase and thermodynamic condition of primary silicon refinement in the mixing process were studied. The results show that the primary silicon can be refined obviously and the size of the primary silicon can reach 37 μm in the preparation of hypereutectic Al-20%Si alloy fabricated by liquid-liquid mixing. When the temperature of high silicon alloy increases, the primary phase size increases. When the high silicon temperature is over 790 ℃, the refinement effect of primary silicon is lost. Additionally, when the Gibbs free energy of the liquids prior to mixing is less than the Gibbs free energy of the resultant liquid at its liquidus temperature ( final,liquidusmG =-39.336 6 kJ), the primary silicon phase will be refined obviously.