thermal spray basics processes GTV （热喷涂基本流程制造中心）.pdf

Basics of Thermal Spray Technology I Processes Andreas Wank GTV Verschleiss-Schutz GmbH, Luckenbach, Germany 1. Introduction The importance of coating technologies and among them thermal spraying is constantly rising, because coatings permit to exploit cost saving potentials by combination of base materials that fulfill the structural demands (stiffness and strength) with coating materials that fulfill the demands on the components surfaces (corrosion resistance, wear resistance, electrical isolation or conductivity, thermal isolation, catalytic function, decorative effect, etc.). E.g. for components that are subject to severe stress conditions such material compounds can be provided at significantly lower cost than bulk material solutions that cover both structural and surface demands. Additionally repair of damaged or worn surfaces of costly components is an important application field for thermal spray processes. The standard DIN EN 657 comprises the different processes that belong to the group of thermal spray processes. Therein, thermal spraying is defined as a process, in which the feedstock is fed inside or outside a spraying gun and heated up to molten state or at least to a state of high plastic deformability. The feedstock is propelled unto a prepared surface that is not molten during the spraying process. The most important distinction refers to the applied energy source: • thermal spraying by atomization of a melt, i.e. melt bath spraying (MBS) • thermal spraying by gaseous or liquid fuels, i.e. wire flame spraying (WFS), high velocity wire flame spraying (HVWFS), powder flame spraying (PFS),