Characterization of Ni-P Amorphous Phase Formation in an Ni-Al Alloyed Layer Produced Using a Pulsed Nd-YAG Laser Beam
Y. Yang and J-D. Hu
Ni-P electroless deposited coating containing 6.74% P was prepared on aluminium substrate. A Nd-YAG pulsed laser was used to alloy the materials at the condition of power density 5.36 × 109 W/m2 and scanning speed 3.0 mm/s. Ni-P amorphous phases could be obtained in the laser alloyed layer. The distribution characteristics of Ni-P amorphous phases was studied by transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM), which clearly showed most of Ni was mixed with Al to form Al3Ni, possessing homogeneous distribution. A great amounts of Ni-P amorphous phases were revealed to exist in featureless zone or Al-rich areas surrounded by Al3Ni.
Keywords: Nd:YAG laser, pulsed laser beam, laser alloying, Ni-Al, amorphous phases, microstructure