Comparison between acid leaching and siliciding pre-treatments on the erosive wear performance of diamond coatings on cemented carbide substrates

A major difficulty associated with growing diamond on cemented carbide is t he cobalt binder that can cause graphitisation of the growing diamond film. This study investigates the influence of two pre-treatment methods, acid l eaching and silicide formation, on the erosive impact resistance of the dia mond films. The diamond films were deposited onto the treated cemented carb ide substrates (6% Co) using a microwave Surfajet technique. The erosive pe rformance was investigated using a centripetal erosion tester in which SiC particles (60-180 mesh size) were impacted normally onto the coated substra tes at an impact velocity of 12-60 ms(-1). The erosive impact resistance of diamond was found to increase with him thickness in the range 1-11 mum. Th e erosive wear performance of the diamond films deposited on the silicide t reated carbide were found to be comparable with the performance of those ob tained using the acid leaching pre-treatment. (C) 2000 Elsevier Science B.V . All rights reserved.