Pulsed Nd:YAG laser post-treatment Ni-based crack-free coating on copper substrate and its wear properties

Laser post-treatment of Ni–Cu plasma-sprayed layer on copper substrate was conducted by pulsed Nd:YAG laser, and its sliding wear tests were investigated. Optical microscope (OM) and scanning electron microscope (SEM) observations showed that, after the laser post-treatment processing, the obtained Ni–Cu coating had dense and homogeneous structure, as well as metallurgical combination with copper substrate, without cracks found. High microhardness of 347 HV of Ni–Cu coating was obtained, which was almost 3.4 times of Cu substrate (102 HV). The volume loss of copper substrate was nearly 4 times of the laser post-treated sample, under sliding wear tests. With the laser post-treatment of large area crack-free Ni–Cu coating on copper substrate, the seizure tendency of Ni–Cu coating was much more suppressed, resulting in the improvement of wear properties.