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

In this paper,the structure,sod idif ication characterstic,mechanical properties,thermal-expansion coefficent and wear resistance of Zinc-Matrix/crystal silicon,ceramic particulate composites with Theological 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 solidif ication of the alloys,and Al₂O₃ particles disperse on the grain boundary and coarsen the primary phase.Through the investigation to the inf luence 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.