Effect of Post-Annealing on Structural, Tribological, and Adhesion Properties of TiW/TiWSi Graded Composite Films

Abstract

TiW/TiWSi/TiWSiN graded composite films were synthesized on AISI 52100 steel substrates by employing a radio frequency (RF)-powered magnetron sputtering technique. Following deposition, post-annealing was applied to the films at various temperatures. X-ray diffraction (XRD) analysis revealed that the films exhibited an amorphous structure prior to annealing. Upon heat treatment, the formation of TiN crystalline phases with various orientations and planes became dominant in the structure. The crystalline formations were identified and validated by means of X-ray photoelectron spectroscopy (XPS). The A-600 film exhibited the lowest values in both friction coefficient (0.13) and wear rate (2.16 x 10-6 mm3/(N & sdot;m)) among all samples. Given these results, the A-600 film demonstrated notable wear resistance and exhibited the best tribological performance among the tested samples. Furthermore, heat treatment was found to improve adhesion performance; however, it was evident that the treatment temperature must be carefully optimized. While only the A-600 film remained intact after the scratch test, the presence of microcracks and cohesive failures in the other films indicated a loss of structural integrity. This study revealed that Ti-W-Si-N-containing films can achieve enhanced hardness, tribological, and adhesion properties following an appropriate heat treatment.