机械搅拌器对C-SiC/Cu半固态浆料中石墨颗粒和SiCP的影响  

Effect of mechanical stirrer on graphite particles and SiCP in C-SiC/Cu semi-solid slurry

作　　者：李鸿武 杜云慧[1] 张鹏[1] 曹海涛 苏丽洁 LI Hongwu;DU Yunhui;ZHANG Peng;CAO Haitao;SU Lijie(School of Mechanical,Electronic and Control Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学,机械与电子控制工程学院,北京100044

出　　处：《复合材料学报》2020年第11期2853-2860,共8页Acta Materiae Compositae Sinica

基　　金：北京市自然基金资助项目(2162036)。

摘　　要：利用直桨叶搅拌器在圆柱坩埚内机械搅拌C-SiC/Cu半固态浆料,研究搅拌速度为200 r/min、搅拌器上下移动速度为10 mm/s时C-SiC/Cu半固态浆料中石墨颗粒和SiC颗粒(SiCP)的均匀性。结果表明:直桨叶与水平面的夹角γ与两种颗粒在坩埚顶部和底部含量偏差都存在二次关系,当γ=30°时石墨颗粒和SiCP在坩埚中轴向分布均匀,但同一水平面内的SiCP仍存在偏聚现象,说明SiCP的偏聚是导致常规直桨叶机械搅拌C-SiC/Cu半固态浆料整体不均匀的主要原因;利用双层桨叶搅拌器代替常规直桨叶搅拌器,通过调整叶片层间距h,当h=10~20 mm时可以消除SiCP的偏聚现象;通过对单层桨叶搅拌器和双层桨叶搅拌器机械搅拌铸造获得的C-SiC/Cu复合材料进行磨损试验发现,单层桨叶搅拌器不同部位磨损率存在差异,双层桨叶搅拌器磨损率几乎相同。说明SiCP的偏聚可以通过增大机械搅拌剪切力度得以消除,利用双层桨叶搅拌器进行机械搅拌可以获得均质的C-SiC/Cu半固态浆料。The mechanical stirring of C-SiC/Cu semi-solid slurry was conducted in a cylindrical crucible by a straight-blade stirrer.The distribution of graphite particles and SiC particles(SiCP)in the C-SiC/Cu semi-solid slurry was studied under 200 r/min for stirring speed and 10 mm/s for speed of moving up and down of stirrer.The results show that there is a quadratic relationship between the angleγbetween the straight blade and the horizontal plane and the content of the graphite particles and SiCP in the top and bottom of the crucible.Whenγ=30°,the axial distributions in the crucible of graphite particles and SiCP are homogeneous,but the SiCP are still segregated,which indicates that the segregation of SiCP leads to the unhomogeneity of C-SiC/Cu semi-solid slurry in conventional straight-blade mechanical stirring.The double-blade agitator is used instead of the conventional straight blade agitator to adjust the blade layer spacing h to 10–20 mm,which can eliminate the segregation of SiCP.The wear tests of the C-SiC/Cu composites obtained by mechanical stirring casting with single blade stirrer and double-layer blade stirrer were carried out.The wear rates of different parts of C-SiC/Cu composites in the single blade mechanical stirring casting are different,however,they are nearly the same in the double-layer blade.It shows that the segregation of SiCP can be eliminated by increasing the mechanical agitation shearing action.The uniform distribution of C-SiC/Cu semi-solid slurry can be achieved by double-layer-stirrer mechanical stirring.

关 键 词：铜基复合材料 颗粒增强 均匀分布 双层搅拌器 机械搅拌 

分 类 号：TG249[金属学及工艺—铸造]