Thermal spraying composite powder characteristics and preparation method

       Composite powder is a particle formed by mechanical agglomeration of two or more solid-phase material particles with different properties rather than alloying, and is divided into agglomerated composite powder, coated composite and sintered composite powder materials. The coating has the common characteristics of the base phase material and the composite phase material.



The components of composite powder materials are: metal and alloy, metal + ceramic, metal + cermet, ceramic + ceramic, metal + plastic, ceramic + plastic, etc., including powder of most solid-state engineering materials. Due to the different components or ratios, various composite powders with different functions are derived. It is the coating material with the most variety, the widest function, the fastest development and the widest application range in the thermal spraying industry. The main features are:



1) Coatings with different functions can be prepared by appropriate manufacturing methods, such as hard wear-resistant, anti-friction self-lubricating, wearable sealing, corrosion resistance, oxidation resistance, high temperature resistance, heat insulation, heat radiation, electrical conductivity, insulation , biological function, radiation protection, anti-interference, etc.



2) Unification of the heterogeneity of a single particle and the homogeneity of the powder as a whole.



3) The core powder of the coated powder is protected by the coating layer. During the thermal spraying process, the oxidative burning and thermal decomposition of elements can be avoided or reduced, and the geometric shape and crystal structure of the core particles can be maintained, so as to obtain high-quality products. coating.



4) It is beneficial to improve the bonding strength between the coating particles and the surface of the substrate and the bonding strength between the coating particles.



The preparation methods of the composite powder material include: liquid deposition method, vapor deposition method, slurry spray drying method, smelting atomization method, and sintering-crushing method.