New paper published in npj Materials Degradation on the material degradation of tribologically loaded carbon nanotubes and carbon onions

New paper published in npj Materials Degradation (open access). In cooperation with the group of Frank Mücklich at Saarland University and partners, we have found that coating laser-patterned stainless-steel surfaces with carbon nanotubes (CNT) or carbon onions (CO) can create an effective solid lubrication system. By storing the particles inside the pattern, lubricant retention is improved and depletion in the contact area is prevented. In previous works, we used laser interference patterning to create line patterns with different depths and coated them with CNTs or COs. Friction tests were conducted to study the effect of structural depth on the lubricity of these surfaces, and we found that shallower textures result in lower friction coefficients. Our latest study examines the degradation of the carbon nanoparticles on substrates with different structural depths, and Raman characterization shows severe degradation of both particle types. This degradation is classified within Ferrari’s three-stage amorphization model. Electron microscopy also confirms that CNT lubricity is improved at the cost of increasing particle defectivity, while CO-derived tribofilms experience even more substantial structural degradation.