COMPARATIVE STUDY OF HVOF (HIGH VELOCITY OXYGEN FUEL) AND HVAF (HIGH VELOCITY AIR FUEL) WITH WC-10CO4CR POWDER

• Main Author: Nurfikra, Handio
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/55341
• Institution: Institut Teknologi Bandung

HVOF and HVAF are widely used in various applications requiring coatings with good mechanical properties and high erosion cavitation resistance. Example on the hydroelectric turbine, gate valves, and pum impellers. Meanwhile, WC-10Co4Cr powder has been widely used in coatings. There are several things related to coating, namely cost, use of oxygen, temperature and particle velocity of the coating. This will affect the HVOF and HVAF coatings. Therefore, a research was carried out on the HVOF and HVAF coating using WC-10Co4Cr powder. Through literature from several journals discussing about comparison of HVOF and HVAF coatings, a relationship was investigated and made through graphic images. In this study, HVAF hardness was higher than HVOF hardness. Then, the high elasticity modulus of the HVAF coatings was high with low porosity compared to HVOF. In addition, the cavitation erosion resistance of the HVAF coatings is also higher than HVOF. This is due to the reduced use of oxygen, lower spray temperature, and high velocity spray particles which make the decomposition of WC-10Co4Cr lower. Then, high velocity particles in HVAF can increase compressive residual stresses so that it inhibits crack growth in the HVAF coatings. XRD and SEM showed that the carbide decomposition and porosity of the HVAF coatings were lower.