液相反应烧结制备Al-Si合金半固态坯料

Preparation of Al-Si alloy semi-solid billets by liquid phase reaction sintering

通过Al、Si元素粉末的液相反应烧结制备了用于半固态成形的Al–6%Si(质量分数)合金坯料。研究结果表明,Al–6%Si混合粉末具有较好的冷压成形性能,经500 MPa冷压之后,其相对密度可达到97.6%。混合粉末的冷压压制特性可用黄培云压制方程进行描述。Al、Si元素粉末可以在585℃下发生反应生成液相,液相围绕等轴状的固相Al晶粒形成半固态组织。Al晶粒尺寸和液相含量随着反应时间的增加而增加。Al–6%Si元素粉末的反应烧结是一个液相持续存在的反应烧结系统,可以通过控制反应时间来控制半固态坯料的微观组织。

The Al–6%Si(mass fraction)semi-solid billets were prepared by liquid phase reaction sintering in this paper,using Al and Si elemental powders.In the results,the mixed Al–6%Si powders have the good cold pressing forming properties,and the relative density can reach 97.6%after 500 MPa cold pressing.The cold pressing characteristics of the mixed powders can be described by Huang Pei-yuan pressing equation.The Al and Si elemental powders can react to form the liquid phase at 585℃,which forms a semi-solid microstructure around the equiaxed solid phase Al grains.At the same time,the Al grain size and the liquid phase content of Al increase with the increase of reaction time.The reaction sintering of Al–6%Si elemental powders is a reaction sintering system with the continuous liquid phase,and the microstructure of the semi-solid billet can be controlled by controlling the reaction time.