Exploring the nanoscale mechanisms of Ni-P system to examine the suitability as joining material for high temperature applications

Nickel phosphide is a valuable material in high-temperature brazing and joining applications, offering excellent thermal stability for temperatures up to 400°C. Nickel phosphide is used as powder form for joining applications and therefore it is imperative to study the formation as well as interaction of Ni2P particles with adjacent particles in an in-situ/in-operando manner for high temperature joining applications. This is the first report on direct observation of synthesis of nickel phosphide with in-operando control over the synthesis parameters obtained by gas phase synthesis methods. This research work is aimed at understanding the phase formation, phase stability, and joining of nickel phosphide nanoparticles diluted gaseous environment containing a phosphorous containing gas with dilution obtained with H2. In this present work, the phase transformation and phase stability of nickel phosphide Ni2P is studied utilizing in-situ Environmental Transmission Electron Microscope for gas experiments wherein the effect of the size of nanoparticle, reaction temperature, isothermal/ non-isothermal annealing, and low-pressure operating conditions on phase transformations as well as phase stability is investigated and reported.