Microstructural and thermochemical properties of Al/AlN/CuAl2 composite prepared by a combination of combustion synthesis and spark plasma sintering

A combination of combustion synthesis (CS) and spark plasma sintering (SPS) technology was employed in the fabrication of Al/AlN/CuAl2 dense composites. Al/AlN/CuAl2 composite powders in which a portion of the AlN was present in macro- and nanofiber forms were prepared by combustion of Al–Cu–5 wt.% (C2F4)n, under a nitrogen atmosphere. The resulting composite powders were then subjected to consolidation by SPS at a dwell temperature level of 1500 °C, mechanical pressure of 60 MPa, and a non-isothermal heating time of 10 min. It is found that the actual thermal conductivity of Al/AlN/CuAl2 composites fabricated with 5 wt.% (C2F4)n is much higher than that of materials prepared in the absence (C2F4)n. Maximum thermal conductivity (320 W/m K) was recorded for the samples prepared from an 0.8Al–0.2Cu–5 wt.% (C2F4)n mixture. The influence of (C2F4)n on the growth mechanism of AlN fibers and thermal conductivity of composite samples is discussed in light of the experimental data.