Method for preparing large-size silicon carbide ceramic plate through reactive sintering

Abstract

The invention relates to a method for preparing a large-size silicon carbide ceramic plate through reactive sintering. The method comprises the following steps: weighing 60-85 parts by mass of siliconcarbide, 5-10 parts by mass of graphite powder, 2-5 parts by mass of carbon black and 2-4 parts by mass of an auxiliary agent, carrying out uniform mixing under stirring, adding 5-15 parts by mass ofwater, continuing stirring for uniform mixing, and performing aging to obtain a mud material; subjecting the mud material to pugging and then to extrusion molding through an extruder so as to obtaina biscuit; and conducting drying and sintering to obtain the silicon carbide ceramic plate. According to the invention, a standing charging mode is adopted, so a large number of cracks can be effectively reduced, and cracks caused by shrinkage during drying in the prior art are overcome. According to the method, the large-size silicon carbide ceramic plate can be prepared on a large scale, and theproblems occurring in forming, drying, sintering and other processes in the prior art are solved under the condition that flatness is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of silicon carbide ceramic materials, and relates to a method for preparing a large-size reactive silicon carbide ceramic plate. Background technique [0002] With the continuous expansion of the application of silicon carbide ceramics, there are more and more requirements for the quality and size of silicon carbide ceramics. Among them, large-scale (3500*500*10-30mm) silicon carbide ceramic plates (including hollow plates) have not been mass-produced and have encountered many difficulties. [0003] 1. Selection of molding method: 1) Dry pressing molding has relatively limited size of the press, especially its high pressure requirements, so its production investment is too large, the pass rate is low, and because of its molding method, it cannot be manufactured. Silicon hollow sheet. 2) Grouting molding: the uniformity is difficult to guarantee, and the density of the same section varies greatly during the...

AI Technical Summary

Problems solved by technology

Among them, large-scale (3500*500*10~30mm) silicon carbide ceramic plates (including hollow plates) have not been mass-produced and encountered many difficulties

[0003] 1. Selection of molding method: 1) Dry pressing molding has relatively limited size of the press, especially its high pressure requirements, so its production investment is too large, the pass rate is low, and because of its molding method, it cannot be manufactured. Silicon hollow sheet

2) Grouting molding: the uniformity is difficult to guarantee, and the density of the same section varies greatly during the drying process

3) Extrusion molding: It has no limitation on the size in the length direction, but it will cause a large number of tiny cracks due to excessive length shrinkage during the shrinkage process

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