Synthesis of diamond films on W mono-blocks by MWCVD for modification of fusion materials

Using the plate-to-plate microwave-plasma chemical vapor deposition (MWCVD) method, it is possible to deposit the diamond films on two W mono-blocks simultaneously. Substrate pretreatment was performed by sandblasting with WC particles, which resulted in excellent adhesion of the deposited films. Films with thickness up to about 200 μm and a maximum linear growth rate of 12 μm/h were deposited. Raman spectra of deposits show the presence of pure diamond phase (intense 1332 cm −1 Raman peak, without the presence of D, G graphite peaks). The XRD spectrum shows strong diamond reflections, as well as the presence of WC/W 2 C phase as a consequence of substrate carburization . Due to its chemical and phase purity as well as perfect adhesive property , the deposited diamond films could improve the properties of the plasma facing material under conditions of specific thermal load and chemical attack by the fusion plasma . • Synthesize high quality and uniform diamond films on the plasma facing materials (PFMs) by MWVCD. • The growth of diamond films is promoted by sandblasting without introducing impurities into the fusion reactor. • The changes of the quality and adhesion of diamond films with PFMs at different deposition time are clarified.