【摘要】 利用双筒式机械搅拌装置制备铝铅系难混溶合金。双筒式机械搅拌装置由一对带有螺纹的内外桶构成,当内筒旋转时在内外桶的缝隙形成剧烈的剪切应力场。通过控制桶的转速和内外桶缝隙可以获得0～153.45s-1的剪切速率,温度在0～1000℃之间任意调节。通过计算分析:铝铅合金的半固态流变成形温度区间为570～630℃,同时得到了铝铅合金的固相率随温度变化的关系曲线。此外还确定了转速与剪切速率的关系。并在温度为594℃,固相率为0.5时,采用不同的剪切速率制备铝铅合金锭料,来验证计算结果。理论和试验结果表明,通过机械搅拌的半固态成形技术,可以制备出铅颗粒均匀、弥散分布的铝铅难混溶合金。更多还原

【Abstract】 Al-Pb immiscible alloys have been prepared by double-barrel mechanical stirring device which composed of two rotating tubes with screw thread. With the rotating of inner tube,the gap between the two rotating tubes showed high shear stress field. The shear rate was obtained between 0 and 153.45 S-1 by changing the rotating and the gap while temperature was controlled between 0℃ and 1000℃. The calculated temperature range of the semi-solid of Al-Pb alloy was between 580℃ and 630℃ and the change of the fraction of solid-phase volume with temperature were obtained. The relationship between the shear rate and the rotate speed of motor was also determined. The semi-solid slurry of Al-Pb alloy was prepared in different shear rate when the temperature was 594℃ and the fraction of solid-phase volume was 0.5. Theoretical and experimental results showed that the distribution of homogeneous dispersion of the Al-Pb immiscible alloys have been received by semi-solid process.更多还原