Samples of mixed materials relevant to fusion (W/C/Mg, where Mg is a chemical stand-in for Be) have been synthesized by planetary ball milling. We explore here W-rich compounds, and investigate their structural and physico-chemical properties, both before and after hydrogen plasma exposure. After presenting the synthesis method experimental results are detailed: clear differences between incorporation of magnesium and/or carbon into a tungsten matrix are observed, as reflected in the specific surface area of the samples and their lattice parameters. Indeed, specific surface area decreases with increasing Mg content but increases with C content. The same trend is seen for the lattice parameter. A particular effect seen after hydrogen plasma exposure is attributed to the presence of magnesium which may also occur in the presence of beryllium. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.