THE EFFECT OF NOZZLE CHANNEL NUMBER TO REPEATED IMPACT RESISTANCE ON HVOF COATING WITH CR3C2 – 20 NICR POWDER

• Main Author: Vincent
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/39679
• Institution: Institut Teknologi Bandung

Several tools or components experience repeated impact load, for example excavator. Repeated impact resistance is one of the most important aspects in this tool. Repeated impact resistance can determine the service life of components. Coating could increase the resistance of repeated impact. HVOF thermal spray has high flame temperature and speed which able to produce coating with high density and low porosity thus increase bond strength. Cr3C2 – 20 NiCr powder is usually used in HVOF process because it can produce coating with high wear and corrosion resistance. Impact resistance of coating will be reasearched by looking at the effect of channel number (no channel, 2 channels, and 4 channels) to repeated impact The standard used in repeated impact test is modified ASTM D 2794. Repeated impact test shows that nozzle with 4 channels has the highest repeated impact resistance compare to other channel number of nozzle. Observation with SEM and image analyzer on coating, it is showing that nozzle with 4 channels has 2,42% porosity, nozzle with 2 channels has 2,85% and nozzle with no channel has 4,42%. Low porosity on channel 4 increase the bond strength. The increase of bond strength is caused by high level of particle porosity showed by high level of temperature after the process of HVOF.