Microstructure and Properties of Al-Si-Al2O3 Composites Prepared by Direct Melting
The microstructure and phase composition of Al-Si-Al2O3 composite with Si content of 10.00wt%,7.64wt%were analyzed by optical microscopy,XRD,SEM and phase analysis.The results show that the microstructure of the Al-10.00wt%Si sample is fine and the porosity is high.The grain Al of the matrix is fine and round,and the Si particles mainly aggregate and grow around the grain boundary of the matrix,and partly grow into the grain interior of the matrix.However,the microstructure of Al-7.64wt%Si sample is slightly coarse and the porosity is low.The grain Al of matrix is irregular,the phenomenon of Si grain aggregation is more obvious.The in situ reaction is carried out successfully,the Al2O3 of the Al-10.00wt%Si composite formed by the Al matrix is the reinforced phase.The other lifetime Si does not distribute in the Al matrix,but aggregates around the grain boundary,and some SiO2 remains around the grain boundary of the matrix.During the heating and heating process,the mixed raw materials only generate partial melting phenomenon,the metal droplets precipitate from the mixed raw materials and condense into alloy droplets with extremely high Al content.The alloy droplet density is high,solid solution is dendrite,Si is stripe or needle,and there are small particles of the second phase,containing Al,Si and C elements.
direct meltinginduction heatingmicrostructureAl-Si-Al2O3 composites
NETL
NSTL
万方数据
