The European Ceramic Society


Mar 3, 2022

YCN Newsletter : Women in Ceramics by Marina Ciurans Oset

Plasma Centrifugal Atomization of Cast Tungsten Carbide for Wear Resistant Coatings: Properties and Applications

Oil drilling, ore processing and metal shaping applications, among other, require highly wear-resistant tool materials capable of withstanding harsh working conditions under heavy loads. Transition d-metal carbides containing elements from groups IV-VI are ideal materials for such applications owing to their exceptional physical and mechanical properties.

Among those compounds, non-stoichiometric carbides possess the highest melting temperatures and the highest hardness. However, extremely high production and processing costs make these materials prohibitively expensive for the intended large scale industrial applications. In this context, tungsten carbides become particularly outstanding. These compounds exhibit sufficiently high hardness from room temperature and up to ~1300 K, high Young’s modulus, low thermal expansion coefficient and high temperature and chemical stability.

Stoichiometric WC, which is widely used in the production of wear resistant alloys, is the only tungsten-carbon compound stable at room temperature. However, metastable W2C is progressively attracting more interest owing to suspected higher hardness. Cast tungsten carbide (CTC, also referred to as fused tungsten carbide) results from the eutectoid decomposition of metastable cubic WC1-x carbide containing ~3.95 wt.% C and consists of WC lamellae inserted in a W2C matrix. The presence of metastable W2C phase, together with the biphasic structure of CTC, results in improved hardness and fracture toughness with respect to pure WC or W2C.

Due to excessive brittleness, extremely high sintering temperatures and high material costs, cutting tools are not manufactured from bulk carbides. Instead, carbide powders are used for depositing metal matrix composite (MMC) hardfacing overlays onto steel tools by means of conventional welding processes. To ensure the mechanical integrity and minimize stress build-up within the matrix, spherical CTC powders are preferred over angular CTC powders. Cold crucible atomization, rotary electrode atomization or direct melting, among other, have been reported suitable for the production of spherical CTC. Resulting powders, however, exhibit particle sizes >200 µm, irregular shape and relatively high volume fraction of porosity. A plasma-assisted centrifugal atomization system suitable for processing of CTC was developed by Metasphere Technology AB, currently Höganäs Sweden AB. In this process, angular CTC with particle sizes <3 mm is fed as feedstock material into a rotating crucible, melted by the glow discharge of a plasmatron and ejected into the chamber as a dispersion of fine droplets. Spherical CTC powder obtained after solidification exhibits particle sizes in the range 40-1000 µm with outstanding shape uniformity, exceptionally fine microstructure and significantly higher mechanical properties than conventional CTC.

The main goal of my research project is to better understand the interplay between plasma centrifugal atomization of CTC and the properties of the powders thus produced, ultimately allowing for the development of spherical CTC powders with highly tailored properties. To this end, my current research focuses on extensive mechanical and microstructural characterization of CTC powders, as well as the study of microstructural evolution upon heat treatment and dissolution phenomena of CTC upon coating deposition. This project is run in collaboration between Höganäs Sweden AB and Luleå University of Technology, co-funded by the Swedish Foundation for Strategic Research (SSF) industrial PhD program.


Explanatory text (graphical abstract):
Schematic representation of the plasma centrifugal atomization process, from coarse angular CTC into fine spherical CTC with refined microstructure.


Contact information:

Marina Ciurans Oset

Division of Materials Science, Department of Engineering Sciences and Mathematics

Luleå University of Technology, SE-971 87 Luleå, Sweden

Last news

Jul 4, 2024
ACerS is offering travelling grants of 1.500 $ to attend the two 2024 ECerS Summer Schools

The grants can be allowed to undergraduate, graduate, and Ph.D. students from non-European based universities. The 2024 ECerS Summer Schools will be held prior to Electroceramics XIX (Vilnius, Lithuania - School: 17-18 August 2024)  and Shaping 9 (Warsaw, Poland - School: 24-25 September 2024)!

Jun 27, 2024
2024 ECerS International Ceramist Student Exchange Program – 3rd call!

In the frame of the 2024 ECerS International Student exchange program, ECerS is opening a third call, this time to allow grants to European Students to attend the 2024 Fall meeting of Korean Ceramic Society (COEX) that will be organised by the Korean Ceramic Society in Seoul, Korea, from 16th to 18th October 2024.


Contact us for any information: - We will respond to your inquiry as soon as possible.


Subscribe to our newsletter and receive our latest news.

Our actions

ECerS coordinates and promotes the study of ceramics through the following actions :

ECerS office

Av. Gouverneur Cornez , 4

7000 Mons


Useful links