Internal friction peak and damping mechanism for spray-atomized and co-deposited 6061 Al/SiC_p composite

摘要

In order to obtain an aluminium matrix composite with high damping capacity, 6061Al/SiC_p composite was fabricated by the processing of the spray-atomization and co-deposition. And internal friction of the composite was measured by using the Multifunction Internal Friction Analyser, and microstructure and component of micro-zone of that was analyzed by using Philips-CM200 type TEM and DX-4 Spectrometer. The author found there was an internal friction peak to exist in the range of the testing temperature. The position of the peak will shift towards higher temperature with frequency increasing. And the higher the peak temperature is, the higher the peak value of internal friction is. And the activation energy of the peak was calculated being 1.26 eV. From the analysis of the microstructure, the higher density dislocation was discovered, what were some radiate bows in shape surrounding around SiC_p particle. The typical dislocation morphology is dislocation network in the form of interwove bowed lines, and there are some nanometer-sized precipitates to scatter at the nodes of the dislocation network. From the result of the micro-zone component analysis, it was revealed there were the interstitial atom C with higher concentration compared with that in the near matrix distributing along the dislocation lines.