Abstract
The use of HVOF to produce surface coatings is much known. However, the spraying of inner parts or using it to reproduce a mold form is not always easy due to the high bonding strength of HVOF coatings. On the other hand, plasma formed parts are being used in the aerospatial industry for many years partly because the ease of the releasing process. Using the experience and the method developed in the CPT some years ago, some new materials have been sprayed to obtain thick axy-symmetrical self-standing forms. The process involves mechanical removal method and for these reason, the mould can be used several times with minimal maintenance. Amongst the releasing methods, the more simple is mechanical but it could turn out to be complex if the adhesion by impingement takes place too strongly. Hence, the impingement of the material is studied in this work. The materials are mechanical blends of WC-Co with Co-based alloys. However, prior to spraying, the most suitable material is chosen for a concrete purpose. The work includes a study of the spraying parameters in the structure and the properties of the coatings. XRD, SEM-EDS, roughness, microhardness, ASTM G 99-90 and ASTM G 65-91 wear test are performed to characterize the samples.
