Powder Diffraction Data of Aluminum-Rich FCC-Ti1−xAlxN Prepared by CVD

Abstract

Fcc-Ti1−xAlxN-based coatings obtained by Physical Vapor Deposition (PVD) or Chemical Vapor Deposition (CVD) are widely used as wear-resistant coatings. However, there exists no JCPDF card of fcc-Ti1−xAlxN for the XRD analysis of such coatings based on experimental data. In this work, an aluminum-rich fcc-Ti1−xAlxN powder was prepared and, for the first time, a powder diffraction file of fcc-Ti1−xAlxN was determined experimentally. In the first step, a 10 µm thick Ti1−xAlxN coating was deposited on steel foil and on cemented carbide inserts by CVD. The steel foil was etched and flakes of a free-standing Ti1−xAlxN layer were obtained of which a part consisted of a pure fcc phase. A powder was produced using the major part of the flakes of the free-standing Ti1−xAlxN layer. Following the Ti1−xAlxN coating, a flake of the free-standing layer and the powder were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), selected area electron diffraction and high-resolution transmission electron microscopy (SAED–HRTEM), wavelength dispersive X-ray spectroscopy (WDS) and energy dispersive X-ray spectroscopy (EDS). The powder consisted of 88% fcc-Ti1−xAlxN. The stoichiometric coefficient of fcc-Ti1−xAlxN was measured on a flake containing only the fcc phase. A value of x = 0.87 was obtained. Based on the powder sample, the XRD data of the pure fcc-Ti1−xAlxN phase were measured and the lattice constant of the fcc-Ti1−xAlxN phase in the powder was determined to be a = 0.407168 nm. Finally, a complete dataset comprising relative XRD intensities and lattice parameters for an fcc-Ti0.13Al0.87N phase was provided.