6 results about "Suspension plasma spray" patented technology

The invention relates to the field of high-temperature protective ceramic coatings for aero-engines, and particularly discloses an environmental barrier coating with a gradient structure and a long service life and a suspension plasma spraying preparation method thereof. The specific method comprises the following steps: by taking silicon powder as a raw material, preparing a bonding layer on a silicon carbide ceramic or SiCf / SiC ceramic-based composite material by utilizing an axial powder feeding three-electrode atmosphere plasma spraying system, preparing suspension liquid by taking rare earth silicate RE2Si2O7 and the like as raw materials, and respectively spraying a compact structure RE2Si2O7 middle layer and a columnar crystal-like structure RE2Si2O7 surface layer; and the prepared state coating is placed in Ar atmosphere and subjected to high-temperature annealing treatment, and the environment barrier coating with the high crystallinity and the gradient structure is obtained. The coating prepared by the invention has gradient transition structural characteristics, has excellent thermal shock resistance in actual tests, and has important application significance in prolonging the service life of silicon carbide ceramic or SiCf / SiC ceramic-based composite materials.

The application discloses a high-temperature wear-resistant coating suspension, a high-temperature wear-resistant coating and a preparation method and application thereof. The high-temperature wear-resistant coating suspension comprises a solute, a solvent and a dispersant, and the solute comprises NiCr-Cr3C2 composite powder and BaF2 / CaF2 eutectic powder. The preparation method of the high-temperature wear-resistant coating comprises the following steps: adopting a suspension plasma spraying technology, spraying the high-temperature wear-resistant coating suspension, forming a NiCr-Cr3C2-BaF2 / CaF2 coating, and preparing the high-temperature wear-resistant coating. The application further provides a composite coating which comprises a metal transition layer and the high-temperature wear-resistant coating deposited on the surface of the metal transition layer. The suspension plasma spraying technology can form a suspension of fine particles in the spraying process, which helps to improve the melting degree of the particles, improve the coating density, and obtain a coating with a dense structure by controlling the suspension system and the spraying process.

The application relates to the technical field of spraying equipment, in particular to a micro-nano material suspension plasma spraying device, which comprises a fixing frame, a plasma spraying gun and a spraying gun, connecting plates and a workbench are arranged on the fixing frame in an up-down distribution, the plasma spraying gun and the spraying gun are respectively arranged on the connecting plates, one side of the plasma spraying gun is connected with a plasma generator, one side of the spraying gun is connected with a liquid storage tank, a controller is arranged on the side wall of the fixing frame, one side below the connecting plate is further connected with an L-shaped support, a spherical spraying guide is arranged in the middle of the support, a connecting seat connected with the plasma spraying gun is arranged outside the spraying guide, and a connecting port connected with the spraying gun and a cavity are further arranged in the spraying guide. Compared with the prior art, the application effectively solves the problem that the spraying range cannot be adjusted due to the limitation of the size of the spraying gun outlet, and improves the adjustability of the spraying device.

This invention discloses a dense, wear-resistant alumina coating produced by suspension plasma spraying, its preparation method, and its application. The preparation method includes: pretreating the substrate; applying an alumina suspension to the substrate surface using axial suspension plasma spraying technology to obtain a dense, wear-resistant alumina coating; wherein the process parameters for the axial suspension plasma spraying technology include: a spray gun power of 125-150 kW, a spraying distance of 50-150 mm, a liquid delivery rate of 30-120 ml / min, and a substrate surface temperature of 300-600 °C during spraying. The method provided by this invention features simple operation, short production cycle, controllable coating thickness, and high production efficiency. Simultaneously, the prepared alumina coating retains the chemical composition of the sprayed alumina and has advantages such as larger coating size, denser coating structure, higher bonding strength, higher hardness, lower wear rate, and applicability to more substrate types.

The invention relates to the field of bonding layers of thermal / environmental barrier coatings, in particular to a layered hafnium silicate bonding layer which is low in annealing temperature, good in high-temperature phase stability, good in oxidation resistance and matched with the thermal expansion coefficient of a silicon carbide ceramic-based composite material and a preparation method of the layered hafnium silicate bonding layer. The preparation method comprises the following steps: by taking hafnium oxide and silicon oxide as raw materials, firstly preparing hafnium silicate raw material powder through a solid-phase reaction method, then preparing hafnium silicate suspension liquid through a ball milling process, and then carrying out plasma spraying on the suspension liquid, thereby preparing the hafnium silicate bonding layer. Compared with a traditional silicon bonding layer, the novel bonding layer has the advantages that the service temperature is higher, the coating cannot be oxidized to generate thermal growth oxide, and the thermal expansion coefficient of the novel bonding layer is matched with that of a silicon-based ceramic composite material. The novel bonding layer has the remarkable characteristic that the coating also has a unique uniform layered microstructure. The preparation process is simple, the operability is high, the coating performance is good, and the industrial production prospect is wide.

The present application relates to the technical field of ceramic coating preparation, and discloses an etching-resistant ceramic coating and a preparation method thereof. The method comprises the following steps: preparing a multicomponent composite ceramic powder based on yttrium oxide and yttrium fluoride and containing zirconium oxide and aluminum oxide according to phase equilibrium design; performing spray granulation treatment on the powder to obtain spherical feed powder with good fluidity; and preparing the feed powder into a coating by using a plasma spraying process. In the spray granulation step, the ceramic powder is mixed with deionized water, a dispersant and a binder to form a slurry, and the required powder is obtained through centrifugal spray drying and heat treatment. The spraying can be performed by using a supersonic atmospheric plasma spraying process or a suspension plasma spraying process. The present application stabilizes the phase composition of the coating material through phase equilibrium design, and obtains an etching-resistant ceramic coating which is phase-stable, dense and has high bonding strength by combining optimized granulation and spraying processes, and the coating is suitable for protection of semiconductor processing equipment.