High-strength silicon carbide ceramic pipe and manufacturing method thereof

Abstract

The invention discloses a high-strength silicon carbide ceramic pipe and manufacturing method thereof, and belongs to the technical field of engineering ceramic materials. Silicon carbide ceramic powders with different granularities are used as the main raw materials, graphite powder and carbon black are used as binders, and resin is used as a binder. The materials are uniformly mixed by a spray granulation process; an organic plasticizer of cellulose and a lubrication agent are added into the mixture; and vacuum pugging, decaying and extrusion molding are conducted to obtain a pipe base substrate; and the base substrate is subjected to drying solidification, high temperature sintering reaction, sandblast and heat treatment to obtain the high strength silicon carbide ceramic pipe. The pipe biscuit manufactured by the process has high strength and length of more than 4000mm; after sintering, the pipe has strength of 300MPa or more, and has the advantages of moderate density, high thermal conductivity, high fracture toughness, good thermal shock resistance and low cost, and can be widely applied to chemical and metallurgy fields, such as acid and alkaline corrosion and high temperature erosion.

Description

technical field [0001] The invention relates to a method for preparing silicon carbide ceramics, more precisely, it relates to the preparation of high-strength silicon carbide ceramic pipes by an extrusion molding process. The invention belongs to the technical field of engineering ceramic materials. Background technique [0002] Silicon carbide ceramics not only have excellent mechanical properties at room temperature, such as high strength and high hardness, but also have high thermal conductivity and excellent corrosion resistance, and can be used as heat exchange materials in various harsh chemical environments; at the same time, carbonization Silicon also has excellent oxidation resistance, high wear resistance and low friction coefficient, and its high-temperature mechanical properties (strength, creep resistance, etc.) are the best among known ceramic materials. Therefore, silicon carbide ceramics are also excellent heat exchange materials in high temperature and par...

AI Technical Summary

Problems solved by technology

First of all, the prepared silicon carbide ceramics contain high free silicon, generally about 15-20wt%, which greatly affects its corrosion resistance and high temperature resistance, and the actual use temperature does not exceed 1250°C

Second, the currently used mixing process is a dry mixing process. It is difficult to disperse silicon carbide powder and carbon black powder with different particle sizes evenly, resulting in defects such as silicon points and silicon lines in the prepared silicon carbide ceramics, which affect heat transfer. application reliability

Thirdly, the main raw material currently used is coarse powder. Although the cost is low, the density and thermal conductivity of the prepared silicon carbide ceramics are low, the strength is low, and the heat exchange efficiency is poor, so it cannot be effectively used in the field of heat exchange.