Thin-shell structure zirconium oxide powder for thermal spraying

Abstract

The invention provides a thin-shell structure zirconia powder for thermal spraying, the powder particles have a thin-shell spherical or nearly spherical hollow structure similar to a table tennis ball, and the wall thickness of the particles is less than 10% of its outer diameter; due to the thin-shell structure oxidation Zirconium powder is easier to melt. When plasma spraying is used, under the same powder feeding rate, the spraying power can be reduced by more than 40%, and the service life of nozzles, electrodes and other components can be extended by more than 50%; under the same spraying power condition The production efficiency (powder feeding amount) can be increased by more than 40%; using the thin-shell structure zirconia powder of the present invention, the flame spraying process can also be used to prepare zirconia coating. The equipment cost of flame spraying is about one-tenth of that of plasma spraying equipment. At the same time, it has the characteristics of low operating cost, small size, and can be easily transported to the product site for coating construction.

Description

technical field [0001] The invention belongs to the field of ceramic coating materials, in particular to a thin shell structure zirconia powder for thermal spraying. Background technique [0002] Zirconia coating has a high melting point, extremely low thermal conductivity and good chemical corrosion resistance, etc., and is often used for thermal protection of working parts at high temperatures. According to different temperatures, zirconia has three different phase structures: monoclinic, tetragonal and cubic, and the three different phases are accompanied by large volume changes during the process of mutual transformation. Therefore, in the application process, usually according to In the environment of its application, phase stabilizers such as yttrium oxide, magnesium oxide, calcium oxide, cerium oxide, etc. are mixed into zirconia to inhibit the phase transition and prevent the volume change during the phase transition from causing the coating to crack. [0003] Com...

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Problems solved by technology

Although the above method can solve the problem of powder melting, it also brings the following disadvantages: (1) when the mass of powder particles is small, and the powder sent into the high temperature area is severely burned; (2) in order to ensure that the powder is fully melted , to prevent the presence of "cooked powder" in the coating, generally use a lower powder feed rate, resulting in low production efficiency and easy thermal stress in the coating

Especially when spraying with an inner-hole spray gun, since the inner-hole spray gun generally operates at a lower power, it usually requires a very low powder delivery rate; (3) In the case of high spraying power and low main air flow, Not only the energy consumption is high, but also the thermal protection of the non-spraying parts of the workpiece is difficult. At the same time, the consumption rate of components such as nozzles and electrodes increases, and the production cost becomes higher.

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