Alloying of cold-sprayed Al–Ni composite coatings by post-annealing

A new cold spray coating technique for thick Al coating with finely dispersed Al–Ni intermetallic compounds was tested. For easy powder preparation and high yield, rather than using of Al/compound mixture feed stock, the spraying of pure Al and Ni powders mixture followed by postannealing was suggested. The powder composition of Al and Ni was 75:25, and 90:10 (wt.%) to expect full consumption of pure Ni into intermetallic compounds. After Al–Ni composite coatings, the Ni particles were finely dispersed and embedded in the Al matrix with a good coating yield. Above 450 8C of post-annealing temperature, the Al3Ni and Al3Ni2 phases were observed in the cold-sprayed Al–Ni coatings. The Ni particles in the Al matrix were fully consumed via compounding reaction with Al at 550 8C of the annealing temperature