Silicon carbide short fiber toughened and strengthened silicon carbide ceramics and preparation method thereof

Abstract

The invention discloses a preparation method of silicon carbide short fiber toughened and strengthened silicon carbide ceramics, which takes silicon carbide powder, yttrium aluminum garnet and silicon carbide short fiber as the main materials and sequentially comprises the following steps of: 1) adding the main materials, a caking agent and a dispersant into de-ionized water and preparing water-based silicon carbide slurry after ball-mill mixing; 2) adopting a sponging drying technique to carry out spray drying to the water-based silicon carbide slurry; 3) adopting 160-200MPa to carry out dry pressing and shaping to the obtained strengthened silicon carbide palletizing powder to obtain a silicon carbide biscuit; and 4) arranging the silicon carbide biscuit in a vacuum pressureless sintering furnace for sintering to obtain the silicon carbide short fiber toughened and strengthened silicon carbide ceramics. The invention simultaneously provides the silicon carbide short fiber toughened and strengthened silicon carbide ceramics prepared by the method. The silicon carbide ceramics is characterized by larger fracture toughness, high mechanical strength, and the like.

Description

technical field [0001] The invention relates to a preparation method of silicon carbide short fiber reinforced silicon carbide ceramics. Background technique [0002] Silicon carbide ceramics is a new type of covalently bonded ceramic material, which has the characteristics of high hardness, wear resistance, corrosion resistance, and high temperature performance. It has been widely used in high-tech fields such as machinery, chemical industry, energy, and military industry. For example, used as high-temperature, wear-resistant, corrosion-resistant mechanical seal components, various grinding wheels and abrasive tools, substrate materials for high-efficiency heat exchangers and large-capacity ultra-large-scale integrated circuits, atomic reactor structural materials, rocket exhaust nozzles , Rocket combustion chamber lining, reflector body, etc. Although silicon carbide ceramics have many excellent properties and are used in many fields, silicon carbide ceramics, like other ...

AI Technical Summary

Problems solved by technology

[0006] 1) Whether it is whisker reinforcement or fiber reinforcement, the biggest difficulty in the process is that due to the difference in structural shape and specific gravity, it is difficult to achieve uniform dispersion between the reinforcing element and the matrix, so that the reinforcing effect is not good, or even Affects the properties of silicon carbide itself; therefore, it is particularly important to take measures to homogenize the composite components

However, the currently disclosed patents consider composites more from the morphology and size of the reinforcement phase, but do not focus on the dispersion modification of the reinforcement phase and the use of new technologies to achieve uniform distribution of the reinforcement phase.

[0007] 2) At present, most of the silicon carbide fibers in silicon carbide fiber-reinforced silicon carbide ceramics are continuous fibers. Can be used in special fields

[0008] 3) At present, most whisker or fiber-reinforced silicon carbide-based composite materials adopt processes such as hot pressing sintering, hot isostatic pressing sintering or gas phase infiltration. These preparation processes are complicated and costly, and it is difficult to realize industrial production. It is necessary to adopt a pressureless sintering process with superior comprehensive performance and relatively simple process cost to realize the industrial production of fiber reinforcement and its composite ceramic materials