Supersonic Laser Deposition of Wear-Resistant and Low-Friction Coatings
Surface treatments and coatings are used to enhance the performance of an underlying component, structure, or substrate. Supersonic Laser Deposition (SLD) is a novel solid-state deposition technology recently developed within the IfM. In SLD, coating particles are accelerated by nitrogen gas to high velocities towards the substrate. Upon impact with the substrate, these particles undergo plastic deformation, adhering to the substrate through a combination of mechanical interlocking and metallurgical bonding between particles. A laser softens the deposition zone to assist with bonding at lower particle velocities. Compared to Cold Spray, SLD is more cost effective because it uses nitrogen rather than helium as the carrier gas. In addition, compared to other thermal spray processes, SLD has achieved improved coating quality due to the non-melting and low-temperature nature of the process.
The central theme of this research project revolves around the development of low-friction and wear-resistant coatings deposited via SLD. The unique attributes of SLD allows for the deposition of thermally sensitive materials without altering the integrity and purity of the coating composition. It is also possible to deposit non-metallic particles by combining them with metal particles in the feedstock mixture. Depending on the desired function of the coating, non-metallic particles can be incorporated by simple mixing of different types of particles or by encapsulating individual non-metallic particles with a thin metallic cladding. It is through this combination of metallic and non-metallic particles that low-friction and wear-resistant coatings can be rapidly deposited.
This project investigates the incorporation of non-metallic particles into a metal matrix for deposition via SLD. Knowledge gained about the fundamental characteristics of specific material combinations will contribute to the development of state-of-the-art composite coatings. The performance of these coatings will be evaluated. Further study will focus on how to deposit these coatings onto specific mechanical components.