Influence of W Addition on Microstructure and Resistance to Brittle Cracking of TiB₂ Coatings Deposited by DCMS

• Main Authors: Edyta Chudzik-Poliszak, Łukasz Cieniek, Tomasz Moskalewicz, Kazimierz Kowalski, Agnieszka Kopia, Jerzy Smolik
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Materials
• Subjects: TiB₂-W coatings; magnetron sputtering; XRD; TEM; XPS
• Online Access: https://www.mdpi.com/1996-1944/14/16/4664

The aim of this work was to determine the influence of the tungsten addition to TiB₂ coatings on their microstructure and brittle cracking resistance. Four coatings of different compositions (0, 7, 15, and 20 at.% of W) were deposited by magnetron sputtering from TiB₂ and W targets. The coatings were investigated by the following methods: X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). All coatings had a homogeneous columnar structure with decreasing column width as the tungsten content increased. XRD and XPS analysis showed the presence of TiB₂ and nonstoichiometric TiBx phases with an excess or deficiency of boron depending on composition. The crystalline size decreased from 27 nm to 10 nm with increasing W content. The brittle cracking resistance improved with increasing content of TiBx phase with deficiency of B and decreasing crystalline size.