Large grain spherical sub-micron/nano composite fiber-ceramic powder

Abstract

The present invention relates to ceramic material technology. The composite fiber-ceramic powder consists of two or three of the following materials: submicron powder of below 1 micron size in 60-97wt% of one or two selected from alumina, zirconia, cobalt clad carbide, Ni-Cr carbide, SiC and SiN; nano-grade powder of below 100 nm size in 2-40 wt% of one or two selected from alumina, titania, zirconia, silica, SiC and SiN; and short fiber ceramic of 1 micron below diameter and 5 micron below length in 3-10 wt% of one selected from alumina, SiC and SiN. Inside the large particle powder, the components have close combination, good flowability and excellent transportation characteristic, so that the composite powder may be used in hot spraying, laser melting and covering and other surface process and ceramic sintering to prepare excellent composite ceramic coating and block.

Description

technical field [0001] The invention relates to a large-particle spherical ceramic composite powder, in particular to a large-particle spherical micro / nano / fiber ceramic composite powder used for thermal spraying, laser cladding and sintering, and belongs to the field of ceramic materials. Background technique [0002] Thermal spraying and laser cladding traditional micron-sized ceramics and their composite ceramic powders are widely used in industry because they can prepare ceramic coatings with excellent properties such as wear resistance, oxidation resistance, and corrosion resistance. However, due to the fact that most of the particles of the traditional micron-sized ceramic powder are in a completely melted state during spraying or cladding, the coating has a high content of metastable phase growth, high porosity, and large residual stress. Therefore, the gap between the coating and the substrate, the coating The internal strength and toughness are poor, which can easil...

AI Technical Summary

Problems solved by technology

However, the powder involved in this document is only composed of nano-scale ceramic powder, and does not involve large-particle spherical sub-micron / nanometer / short-fiber ceramic powders composed of powders of more than two sizes in the three primary ceramic powders of submicron, nanometer, and short fiber. Fiber-ceramic composite powder, and the nano-particles in the coating prepared by thermal spraying or laser cladding from pure nano-powder powder grow significantly, and the porosity is high, and its performance does not achieve the expected effect

In addition, the high cost of the coating prepared from pure nano-ceramic powder greatly limits its application in civil industry

Due to the small mass and large specific surface area of ​​the ceramic powder with a scale of submicron, nano and short fibers, its fluidity is poor, and it is very easy to block the pipeline during the spraying process. On the other hand, this single The component powder and its directly mixed powder have a small impulse, and are easy to grow during the thermal spraying process, and cannot form a dense thermal spraying coating, resulting in poor coating performance. Therefore, this type of powder cannot be directly applied to thermal spraying