W eight at. for Mo, Re and Zr and below 16 at. for Cr. Above this limit both diborides (W,TM)B2 are produced. Addition of transition metals brought on lower of density and enhance of hardness and electrical conductivity of sintered compacts. Deposited coatings W1-x TMx By (TM = Cr, Mo, Re, Zr; x = 0.2; y = 1.7) are homogenous, smooth and difficult. The maximal hardness was measured for W-Cr-B films and under the load of 10 g was 50.four four.7 GPa. Deposited films possess comparatively high fracture toughness and for WB2 coatings alloyed with zirconium it is actually K1c = two.11 MPa m1/2 . Keyword phrases: ternary tungsten boride; spark plasma sintering; magnetron sputtering; electrical conductivity1. Introduction Nowadays the rise of a broad class of compounds comprising heavy transition metal (TM) and light-element atoms, like nitrides, carbides, and borides is often observed. Such compounds possess excellent mechanical properties including higher hardness and higher wear resistance, refractory properties as well as good thermal and electrical conductivity resulting in the concurrently high valence electron density and sturdy covalent bonding in these compounds [1,2]. These advanced ceramics can locate α-Thujone Technical Information applications in key technological fields, like cutting and drilling tools, wear resistant coatings, and engine components [3,4]. Having said that, a major challenge remains in that the applications are to create reliable tool components created of those materials inside a reasonably easy and time-consuming manner. This challenge is partly resolved by deposition of thin films [5] building effortlessly machinable components [3] or new methods of sintering [9]. For much better electro machining the good electrical conductivity is needed. Amongst such compounds, tungsten diborides (WB2) alloyed with other TM are particularly promising for their extremely higher hardness accompanied with elevated toughness and very good electrical conductivity [10,11]. The theoretical research have showed that WB2 doped by TM can possess the quite higher hardness above 40 GPa [1,5].Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.Copyright: 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access write-up distributed below the terms and situations from the Inventive Commons Attribution (CC BY) license (licenses/by/ 4.0/).Coatings 2021, 11, 1378. ten.3390/coatingsmdpi/journal/coatingsCoatings 2021, 11,2 ofOne of greatest candidates of WB2 alloying is rhenium (Re). Diboride of this metal is superhard and may crystalize in related to WB2 hexagonal AlB2 -type structure [12]. The addition of rhenium in to the WB4 and W2 B5 phases happen to be reported by Mohammadi et al. [13] and by Feng et al. [14]. Using the addition of 1 at. Re, the Vickers microhardness elevated to roughly 50 GPa at 0.49 N. Obtained tungsten tetraboride (WB4) with 1 at. Re admixture is thermally stable up to about 400 C in air. In the case of Re alloyed W2 B5 theoretical research showed that W1.5 Re0.five B5 and W0.5 Re1.5 B5 are energetically and thermodynamically stable. The calculated hardness of W2 B5 and W0.5 Re1.five B5 was 16.11 and 17.91 GPa, respectively. On the other hand, ReB2 alloyed by tungsten was studied experimentally by Lech et al. [15]. The strong options of tungsten in ReB2 happen to be successfully synthesized by utilizing an electric-arc furnace. The solubility limit for tungsten in ReB2 is almost 48 at. , which indicates a very higher degree of solubility. The research.