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采用粉末冶金法制备含CeO_2的SiC_p/Al-Si复合材料,研究CeO_2的添加量对复合材料显微组织的影响,探讨CeO_2在烧结过程中对Si析出的作用机理。结果表明,添加CeO_2可以有效细化析出Si颗粒的平均尺寸,并提高析出Si颗粒的数量。CeO_2的最佳添加质量分数为0.6%,过高或过低的CeO_2含量会降低细化效果。CeO_2作为析出Si相的非均匀形核基底,提高了析出Si相的形核率,从而细化析出Si颗粒尺寸,提高了析出Si颗粒的数量。
CeO_2-containing SiC_p / Al-Si composites were prepared by powder metallurgy. The effects of CeO_2 loading on the microstructure of the composites were investigated. The mechanism of CeO_2 precipitation during sintering was also discussed. The results show that the addition of CeO 2 can effectively refine the average size of precipitated Si particles and increase the amount of precipitated Si particles. CeO_2 best addition mass fraction of 0.6%, too high or too low CeO_2 content will reduce the refining effect. As a non-uniform nucleation base of precipitated Si phase, CeO 2 increases the nucleation rate of the precipitated Si phase, thereby finely precipitating Si particles and increasing the amount of precipitated Si particles.