Laser processing of thermal spray patterns using femtosecond pulses

Thermal spray coatings are crucial to the economical, safe, and efficient processing of many engineering components. Due to the unique capability to synthesize functional surfaces of a variety of complex systems, thermal spray technology has been widely used in mechanical and aerospace components, manufacturing environments, and biomedical applications. Since the dimension of sprayed patterns is limited by the spray technology, which is generally greater than 500 μm in width, a robust technique to further machine the sprayed materials is highly desired to broaden thermal spray applications into microscale systems. In this work, a Tirsapphire femtosecond laser synchronized with a three-dimensional motorized micro-positioning system is used to experimentally investigate the precise material removal and modification of thermal spray line patterns while maintaining good feature qualities with negligible heating damage. Trimming of thermal sprayed conductor lines are presented, with a 700 μm as sprayed linewidth trimmed to ∼300 μm and a 500 μm linewidth trimmed to ∼50μm, respectively. This work demonstrates that femtosecond lasers are a promising tool for micromachining and surface modification of thermal sprayed patterns.