Mechanical Properties and Reaction Characteristics of Al-ZrH2-PTFE Composites under Quasi-Static Compression

To analyze the mechanical properties and reaction characteristics of Al-ZrH2-PTFE (aluminum-zirconium hydride-polytetrafluoroethylene) composites under quasi-static compression, five types of specimens with different ZrH2 contents (0%, 5%, 10%, 20% and 30%) were prepared by molding-vacuum sintering. The true stress-strain curves and reaction rates of the different specimens were measured using quasi-static compression. The specific reaction processes were recorded by a high-speed camera. The corresponding reaction products were characterized by the XRD phase analysis, the calorific value was tested by a Calorimeter, and the reaction mechanism was analyzed. According to the results, the strength of the composites increased first and then decreased with the increase in the content of ZrH2. It reached a maximum of 101.01 MPa at 5%. Violent reaction occurred, and special flames were observed during the reaction of the specimens with 5% ZrH2. With the increase in the content of ZrH2, the chemical reaction was hard to induce due to the reduction in strength and toughness of composites. The reaction mechanism of Al/ZrH2/PTFE reveals that high temperatures at crack tip induced the reaction of Al and PTFE. Subsequently, ZrH2 decomposed to release hydrogen and generate ZrC. Calorimetric experiment shows that the calorific value of Al/ZrH2/PTFE with 20% ZrH2 is higher than that of Al/PTFE. The findings verify the potential of ZrH2 as an energetic additive for the enhancement of strength and release of the energy of the composites.