Preparation method of extrusion-molded closed-end reaction-sintered silicon carbide ceramic tube

Abstract

The invention discloses a preparation method of an extrusion-molded closed end reaction sintered silicon carbide ceramic pipe. The preparation method comprises the following steps: forming a base material by the following components in content by weight: 65-90 percent of grain size distributed silicon carbide micro-powder and 10-35 percent of carbon / graphite particles; uniformly stirring the grain size distributed silicon carbide micro-powder, the carbon / graphite particles, tetramethyl ammonium hydroxide, water-soluble resin, high-polymer polysaccharide, a lubricating agent and deionized water, hermetically ageing for 1-5 days at room temperature to obtain a slurry material, pugging and ageing in vacuum and then performing extrusion molding to obtain a pipe blank; drying the pipe blank in the shade, shaping, firstly drying by microwave and then performing high-temperature siliconing sintering to obtain the silicon carbide ceramic pipe. The silicon carbide ceramic pipe prepared by the method disclosed by the invention is high in density and uniform in structure.

Description

technical field [0001] The invention relates to a method for preparing a closed-end reaction sintered silicon carbide ceramic tube by extrusion. Background technique [0002] With the development of science and technology, the efficient use of energy and high-temperature temperature measurement technology have received more and more attention from the country. Carbon black production furnaces, stainless steel and alloy smelting furnaces, in order to prevent contact with oxidation or introduce impurity pollution, generally use sealed heating, insert heating tubes in the middle of heated organic gases, metals, and liquids, and seal one end of the heating tubes. The inside of the heating tube is heated by resistance wire, liquefied natural gas or high-temperature liquid as a material that does not react with the contact object. With the development of temperature measurement technology, thermocouple protection tubes play an important role in the temperature measurement process...

AI Technical Summary

Problems solved by technology

[0005] The main molding processes of reactive silicon carbide thermal radiation heating tubes and thermocouple protection tubes include grouting molding and hot die-casting molding. The grouting molding process is very mature. The grouting molding requires that the slurry must be high-solid and low-viscosity. Generally, SiC with different particle sizes is selected. Micropowder is used for particle size grading, the selected SiC particles are relatively coarse, and the general process of grouting molding is cumbersome, the production cycle is long, the product density is low, and the green body density uniformity is poor, resulting in poor oxidation resistance at high temperatures and short service life. Hot die casting is suitable for the production of large-scale products, and the investment in production equipment is large and the production efficiency is low