Enhanced thermal transfer and bending strength of SiC/Al composite with controlled interfacial reaction

摘要

The interface and its effect on the thermal conductivity and bending strength of SiC/Al composite were investigated. The results indicated that the compact interfacial layer could be obtained when holding the SiC particles for 4 h at 1200 ℃ The decrease of the holding time reduced the thickness of the interfacial layer, yet harmful for the thermal transfer of the interface due to the formation of pores and Al_4C_3. The prolongation of the holding time introduced SiO_2 layer owning the very low instinct thermal conductivity, resulting in the increase of interfacial thermal resistance. However, the addition of SiO_2 layer seems less harmful for the interfacial thermal transfer with respect to the thin SiC＞2 layer. The critical thickness of SiO_2 layer is confirmed to be 210 nm. Very similar to the variation of thermal conductivity, the bending strength follows a first increase until reaches a maximum value 435 Mpa and then trends to decrease. The composite after T6 treatment exhibits a better bending strength compares to T2 treated composite.