Simultaneous optimization of nanosecond laser ablation and frictional characteristics of tantalum carbide coated graphite substrates

摘要： Tantalum carbide (TaC) is a potential candidate for high temperature applications such as rocket nozzles and thrust petals. Laser surface modi?cation of such transition metal carbides imposes challenges in the selection of laser parameters to achieve controlled microstructure, reduction in porosity, surface roughness and higher wear resistance. The present research focuses on in-vestigating the e?ects of laser ablation parameters such as pulse energy, scanning speed, line spacing and their interactions on surface roughness and CoF of tantalum carbide coated graphite substrates. Regression models were developed to establish a correlation between surface roughness and coe?cient of friction along with laser parameters. The contribution of pulse en-ergy was found to be more signi?cant on CoF, whereas line spacing had a greater in?uence on the surface roughness of the TaC coatings. The optimal condition to obtain minimum surface roughness and CoF was achieved at a higher pulse energy of 250 μJ, lower scanning speed of 100 mm/s and lower line spacing of 10 μm.