High Velocity Oxy Fuel Thermal Spray Gun Design

Abstract

High-velocity oxy–fuel (HVOF) thermal spraying was developed in 1930 and has been commercially available for twenty-five years. HVOF thermal spraying has several benefits over the more conventional plasma spray technique including a faster deposition rate which leads to quicker turn-around, with more durable coatings and higher bond strength, hardness and wear resistance due to a homogeneous distribution of the sprayed particles. HVOF thermal spraying is frequently used in engineering to deposit cermets, metallic alloys, composites and polymers, to enhance product life and performance. HVOF thermal spraying system is a highly promising technique for applying durable coatings on structural materials for corrosive and high temperature environments in advanced ultra-supercritical coal-fired (AUSC) boilers, steam turbines and gas turbines. HVOF thermal spraying is the preferred method for producing coating with low porosity and high adhesion. HVOF thermal spray process has demonstrated to be one of the most efficient techniques to deposit high performance coatings at moderate cost. This publication is devoted to shed light on the design aspects and test equipment requirements for liquid fuelled HVOF thermal spray gun. The current research provides extensive understanding of several key process parameters to develop design tools for the next generation liquid fuelled HVOF thermal spray system for high temperature and harsh environment applications.