What is thermal spraying?

Thermal spraying is a kind of surface strengthening technology and an important part of surface engineering technology. It is a technology which will use heat source (such as arc, plasma spraying and combustion flame, etc.) to melt powder or filiform metal or nonmetal material heated to melting or semi-melting state, and then with the help of a flame itself or compressed air to inject to the pretreatment of substrate surface at a certain speed, deposit and form surface coating with a variety of functions.

Principles of thermal spraying

It refers to a series of processes which fine and dispersed metallic or nonmetallic coating materials are deposited on the surface of a prepared substrate in a molten or semi-molten state to form a coating deposit. The coating material may be powdery, banded, filiform, or rod-like. The thermal spraying gun provides the necessary heat from the fuel gas, arc or plasma arc, after that it heats the thermal spraying material to the plastic or melting state, and then undergoes the acceleration of compressed air, so that the constrained grain bundles impact on the surface of the substrate. The grains impinged on the surface, deform as a result of stamping, form laminated sheets, adhere to the prepared matrix surface, and then cool and accumulate, eventually forming a layered coating. The coating can be resistant to high temperature corrosion, wear resistance, heat insulation, electromagnetic wave and other functions due to different coating materials.

Definition

Thermal spraying is a metal surface processing method in which melting spraying material is atomized and sprayed on the surface of parts by jet stream to form a spraying layer. We call the special working surface “coating”, and the process of working method “thermal spraying”, which is the generic term of various heat sources for spraying and spray welding.

Purpose

Under the action of high-speed airflow to atomize into micro droplet or high temperature particles, with high flying speed to spray the treated surface, form a solid layer, so that the workpiece surface will gain hardness, wear resistance, corrosion resistance, heat resistance, oxidation resistance, heat insulation, insulation, conductive, seal, disinfection, microwave radiation, and other various special physical and chemical properties. It can repair the old and profitable waste equipment maintenance, so that the scrapped parts “back to life”; Can also be strengthened in the new product and pre-protection, so that its “longevity”.

Thermal spraying materials

Spraying powder occupies a very important position in the whole thermal spraying materials. Thermally sprayed alloy powders include nickel-based, iron-based,cobalt-based alloy powders and metal powders such as Manganese Powder, Chromium Powder, Vanadium Metal, are used for the repair and protection of mechanical parts according to the hardness of the coating.