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

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 °C, being 160 °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 mm s^‑1, demonstrating the suitability of the Al₁₂Mg₁₇ additive for enhancing the performance of Ni-Al-based reactive material.