In-situ TiB2 reinforced Al–4Cu matrix composites synthesized through microwave and conventional heating methods: Thermodynamics, dynamics and mechanical properties

Al–4Cu alloy matrix composites reinforced with TiB2 particles are synthesized by microwave heating (MH). The effects of this heating method (as compared to conventional heating (CH)) and the volume fraction of reinforcements on the microstructure and mechanical properties of the composite samples were studied. Assisted by differential scanning calorimetry (DSC) analysis, the thermodynamics and kinetics of the two methods were discussed, respectively. The results showed that the activation energy for TiB2 formation was 33.8 kJ/mol by MH, against 113.8 kJ/mol by CH, suggesting that the microwave sintering facilitated the reaction process. Moreover, as compared to the CH samples, the ultimate tensile strength (UTS) of the composites prepared by MH method was greater and its value increased with TiB2 content at the expense of percent elongation. The UTS increases from 194.1 MPa to 329.1 MPa and the elongation decreases from 13.70% to 6.26%.