Formation of Titanium Nitride, Titanium Carbide, and Silicon Carbide Surfaces by High Power Femtosecond Laser Treatment

Abstract

Invited for this month's cover is the group of Prof. Eike G. Hübner at Fraunhofer Heinrich Hertz Institute HHI, Goslar and Clausthal University of Technology, Clausthal‐Zellerfeld, Germany. The cover picture shows a titanium plate, on which the crystal structure (golden circle=Ti, blue circle=O/N/C) of isomorphous TiO, TiN or TiC, respectively, has been engraved by a high‐power high pulse repetition rate femtosecond laser process. The process allows for a fast and spatially resolved surface transformation of titanium to golden TiN, blue TiO/TiO2 or black TiC in an atmosphere of nitrogen, air or ethene/argon. The background represents a typical surface microstructure of these interstitial compounds obtained during this transformation. Read the full text of the article at 10.1002/cplu.202100118.

Development, characterization, and cavitation erosion analysis of high velocity oxy-fuel (HVOF) sprayed TiC and (70Cu-30Ni)-Cr based composite coatings on SS316 steel

“…2.1 Materials Used Titanium Carbide (TiC) and Cupronickel-chromium ((70Cu-30Ni)-Cr) particles were deposited on SS316 steel substrate by employing HVOF thermal spray process. TiC provides great resistance to surface erosion by virtue of its high value of Mohs hardness (9-9.5) [37]. Elastic modulus (E) of about 400GPa is adequate for TiC to resist CE as it provides cushioning effect to the material during high intensity pressure waves.…”

“…Mix mode of failure i.e., brittle fracture as well as plastic deformation is found to be the cause of material removal. Although TiC is very hard (micro hardness of 1154 HV 9.81N ) and brittle, there occurs a bit of plastic deformation over the surface owing to its elastic modulus of 400 GPa [37]. Having moderate elastic modulus, TiC coatings allow the surface to deform plastically amid water bubble explosions.…”