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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 microstructure, solidification characteristics, mechanical properties, thermal expansion coefficient and friction and wear properties of zinc-base-crystalline silicon and ceramic particle composites fabricated by the rheological casting process are studied. It is found that SiC particles can be used as the nucleation substrate for the primary phase of high-Al-Zn-based alloys, which can be distributed in the grains and can refine the grains. The distribution of silicon particles is related to the crystallization characteristics of the alloy. However, Al 2 O 3 particles are distributed in grain boundaries and tend to coarsen the primary phase. The effect of the particles on the mechanical properties of the Zn-based alloys was also studied. It was found that the tensile strength of the alloy slightly decreased and the hardness increased. The elongation and toughness of the alloy were improved when the content of the particles was appropriate. After the particles are added, the thermal expansion coefficient of the zinc-based alloy is reduced, and the wear resistance is obviously improved, so that the zinc-based alloy can better meet the requirements of the mold and the bearing material.