Influence of Al12Mg17 Additive on Performance of Cold-Sprayed Ni-Al Reactive Material

Abstract

Ternary Ni-Al-Al12Mg17 and binary Ni-Al reactive materials were obtained by cold spraying. The reactive performance of both materials was compared to explore the influence of the Al12Mg17 additive. According to differential scanning calorimetry–thermogravimetric analysis–derivative thermogravimetry, the Ni-Al-Al12Mg17 thermal explosion reaction produced a peak at 480\xa0°C, being 160\xa0°C lower than that of binary Ni-Al. The high-resolution element surface distribution clearly showed the microstructure evolution after controlled annealing and revealed that the rapid oxidation reaction of liquid Mg played a critical role in the occurrence of the thermal explosion reaction in air. During the self-propagating combustion process, the Al12Mg17 additive acted as “ignition spots,” and the Ni-Al intermetallic reaction was ignited by combustion of Mg. The sustained power provided by the Mg combustion promoted the continuous reaction in the Ni-Al matrix. The combustion wave velocity of the Ni-Al-Al12Mg17 material was almost doubled, from 60-100 to 150-200\xa0mm\xa0s−1, demonstrating the suitability of the Al12Mg17 additive for enhancing the performance of Ni-Al-based reactive material.