锌基-结晶硅、陶瓷粒子复合材料的组织与性能

STRUCTURE AND PROPERTIES OF ZINC-MATRIX CRYSTAL SILICON, CERAMIC PARTICULATE COMPOSITES

本文研究了用流变铸造工艺制造的锌基—结晶硅,陶瓷粒子复合材料的组织、凝固特点、力学性能,热膨胀系数及摩擦磨损特性。研究发现,SiC粒子可作为高铝锌基合金的初生相的形核衬底,分布在晶内并可细化晶粒;硅粒子的分布与合金的结晶特性有关。而Al_2O_3粒子分布在晶界,对初生相有粗化趋势。也研究了粒子对锌基合金力学性能的影响,发现合金抗拉强度略有下降,硬度提高,粒子含量适当时延伸率及韧性提高。加入粒子后锌基合金热膨胀系数减小,耐磨性明显提高,从而使其能更好的满足模具,轴承材升的要求。

In this paper,the structure, solidification characterstic, mechanical properties, thermal-expansion coefficent and wear resistance of Zinc-Matrix/crystal silicon,ceramic particulate composites with rheological casting technology are investigated. The results show that SiC particles can be the nucleation basis of the primary phase of Zinc-matrix alloys containing high aluminum, disperse in grains and refine grains.The distribution of Si particles is related to the solidification of the alloys,and A12O3 particles disperse on the grain boundary and coarsen the primary phase. Through the investigation to the influence of the particles on the mechanical properties it is found that the tensile strength is decreased slightly,but the hardness, the ductility and the toughness are increased with a suitable addition of particulate fraction.When particles being added, the thermal expansion coefficient of the alloy is decreased,and wear resistance is improved prominently. These properties may be suitable to the die and bearing materials.