Papers by Keyword: Titanium Aluminum Nitride

Abstract: Ti1-xAlxN films have been shown to exhibit superior mechanical and thermal properties and are thus widely used for industrial applications. We have studied the structural and mechanical properties of fcc-TiN and fcc-Ti1-xAlxN solid solution (x=0.25 and x=0.5), using first principles calculations based on the density functional theory. These calculations provide the lattice parameter, total energy, cohesive energy, elastic constants, etc, of the TiN lattice and when Al atoms replace Ti atoms in the TiN lattice. With regard to the cohesive energy of TiN and fcc-Ti1-xAlxN, we can obtain that the fcc-Ti1-xAlxN is metastable. Via comparation and analysis, it’s shown that the lattice parameter, cohesive energy and elastic constants decrease with increasing the content of Al. However, ductile behavior is promoted by Al addition.

Abstract: CrAlN and TiAlN coatings were deposited on stainless steel substrates by a lateral rotating cathode arc technique. The composition and structure of the as-deposited coatings were analyzed by energy dispersive analysis of X-rays (EDX) and X-ray diffraction (XRD). Thermal conductivity of these coatings is measured using pulsed photothermal reflectance (PPR) technique at room temperature. The measured thermal conductivity of pure TiN coating is around 11.9 W/mK. With increasing Al content, thermal conductivity of the TiAlN coatings decreased significantly and a minimum value of about 4.63 W/mK was obtained at the Al/Ti atomic ratio around 0.72. With the increase of Al content, thermal conductivity of CrAlN coatings decreased slightly but consistently. The variation of thermal conductivity in these coatings is explained in term of phonon scattering on grain boundaries and local strain centers caused by lattice distortion. In comparison with TiAlN, thermal conductivity of CrAlN coatings was evidently lower, which could be partially responsible for their better performance in high speed machining applications as observed in our previous work.

Abstract: The current work focuses on the materials science aspects of the growth phenomena of titanium-based coatings TiN, (Ti,Al)N and (Ti,Al)(C,N) with face-centered cubic lattice structure, deposited by the industrially-styled Pulsed Laser Deposition (PLD) technique at room temperature. hese coating materials are widely spread in mechanical, tribological and decorative applications due to their exceptional physical and chemical properties. Recently, the trend of using temperaturesensitive materials like polymers and tool steels of the highest hardness demands new lowtemperature coating techniques for protective surface finishing as well as for functionalization of the surfaces. These titanium-based compounds can fulfill a wide range of these demands, but up to now there is a lack of industrially designed vacuum coating techniques operating at temperatures lower than 50 °C necessary for these materials. The PLD process is known as one of the most promising candidates for such coating demands. But up to now PLD is only a well-established laboratory coating technology and has not become a standard industrial coating technique despite its outstanding process features. The missing of PLD coating systems, which fulfill the requirements for industrial applications like high-rate deposition and adequate sizes of deposition chambers, is considered as one of the main obstacles for a breakthrough of the PLD technique. To overcome this problem an industrially designed PLD coating system has been developed and built at the Laser Center Leoben of JOANNEUM Research Forschungsgesellschaft mbH.