Abstract
SiCp/Al-Si composites with different CeO2 contents were prepared by a powder metallurgy method. The effect of CeO2 content on the microstructure of the composites was studied. The mechanism of CeO2 on the precipitation of Si during sintering was analyzed by theoretical calculations. The results show that the appropriate amount of CeO2 can significantly refine the size of precipitated Si particles in the composite and increase the number of Si particles. With the increase of CeO2 content from 0 to 0.6 wt%, the number of Si particles precipitated in the composites increases gradually, and the average particle size of Si particles decreases gradually. When the CeO2 content is 0.6 wt%, the number of Si particles precipitated in the composites reaches the maximum, and the average particle size reaches the minimum. However, with the increase of CeO2 content from 0.6 wt% to 1.8 wt%, the number of Si particles precipitated in the composites began to decrease, and the average size of Si particles gradually increased. CeO2 can be used as heterogeneous nucleation substrate of precipitated Si, and the nucleation rate of precipitated Si on a CeO2 substrate is higher than that on an aluminum substrate. The proper addition of CeO2 can improve the nucleation efficiency of precipitated Si, thus increasing the amount and refining the size of precipitated Si.
Highlights
With the development of the modern manufacturing industry, research and development of high-performance materials has become one of the important topics in the development of the aerospace industry [1,2,3]
SiCp/Al-Si composites with different CeO2 contents were prepared by a powder metallurgy method, the influence of CeO2 content on the microstructure of the composites were studied and the mechanism of the influence of CeO2 on the precipitation of Si phase in the composites was discussed
The SiCp/Al-Si composites with different CeO2 contents were prepared by a powder metallurgy method
Summary
With the development of the modern manufacturing industry, research and development of high-performance materials has become one of the important topics in the development of the aerospace industry [1,2,3]. Due to the advantages of low density, high specific strength, low thermal expansion coefficient, good thermal conductivity and high wear resistance, SiC particle reinforced Al-Si matrix composite (SiCp/Al-Si composite) has been widely used in aerospace applications, electronic instruments, military equipment, wear-resistant materials and many other fields [8,9,10,11,12]. For the SiCp/Al-Si composites with high Si content in the matrix, multi-scale precipitation of Si phase will occur during the preparation process, and coarse and irregular. SiCp/Al-Si composites by reducing or preventing the multi-scale precipitation of a Si phase during the preparation process. SiCp/Al-Si composites with different CeO2 contents were prepared by a powder metallurgy method, the influence of CeO2 content on the microstructure of the composites were studied and the mechanism of the influence of CeO2 on the precipitation of Si phase in the composites was discussed
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