Thermomechanical stability of a carbon fiber-reinforced aluminum matrix composite fabricated by spark plasma sintering in various pulse conditions

We investigated the relative thermal expansion of a carbon fiber-reinforced aluminum matrix (Al-CF) composite fabricated by spark plasma sintering (SPS) in various pulse conditions, and attempted to create aluminum carbide (Al₄C₃) at the aluminum/carbon fiber (Al/CF) interface by means of controlled annealing. The thermal expansion behaviors of Al-CF composites became elastic after annealing, despite the brittleness of the annealed Al-CF composite fabricated in the pulse condition which provided higher maximum intensity peaks of voltages and currents than others did (3:3). Although this elastic thermal expansion behavior disappeared when longer fibers we reused, longer sintering time retrieved it. The thermal expansion behavior of Al-CF composite remained plastic under the pulse condition which provided lower maximum intensity peaks of voltages and currents (24:1). In Al-CF composite, the variation of SPS pulse condition controls the Al/CF interfacial condition and the quantity of Al₄C₃ at Al/CF interface after annealing, and determines the thermal expansion behavior of Al-CF composite. (authors)