TiB_2/7075铝基复合材料流变挤压成形工艺

Rheo-casting forming process of TiB_2/7075 aluminium matrix composites

采用原位反应制得纯净的TiB_2/7075铝基复合材料,并经保温二弯通道挤压成形制备半固态TiB_2/7075复合材料。研究表明:在增强颗粒冲刷搅拌和对流的共同作用下,熔体迅速形核并球化;经二弯石墨通道挤压成形,3%TiB_2/7075(质量分数)铝基复合材料晶粒尺寸达到35.9μm,形状因子为0.97;颗粒含量为4.5%时,晶粒尺寸达到22.53μm,形状因子为0.98;颗粒含量为6%时,晶粒尺寸达到28.0μm,形状因子为O.92。

Novel reactive technique was employed in the synthesis of 7075 Al matrix composites, and TiB2/7075 semi-solid composites were prepared by rheocasting forming after flowed through two serpentine graphite channel. The results show that the combination of particles scouring and convection lead to nucleation and globalization of the grain. After the rheocasting process with two serpentime graphites, the mean grain size and shape factor of the 3%TiB2/7075 （mass fraction） composite are 35.7 μm and 0.97, respectively. The mean grain size and shape factor of the 4.5%TiB2/7075 composite and 6%TiB2/7075 composite are 22.53μm, 0.98 and 28μm, 0.92, respectively.