Manufacturing method of silicon nitride bonded silicon carbide ceramic crucible

Abstract

The invention discloses a manufacturing method of a silicon-nitride-combined silicon carbide ceramic crucible. The method comprises the following steps: 1) preparing mixed powder; 2) preparing a premix solution; 3) preparing a curing agent; and 4) manufacturing a crucible biscuit. The manufacturing method disclosed by the invention adopts the premix solution mainly composed of ethyl silicate and acidic silica sol, and the premix solution can be cured with the di-n-butylamine-containing curing agent at normal temperature, so the operating technique is simple; and the premix solution also avoids hydration reaction with the silicon powder in the mixed powder, thereby enhancing the density of the product. In the manufacturing process, the sintering can be directly carried out after drying at room temperature, thereby greatly saving the energy and manufacturing time. The biscuit dried at room temperature has certain hardness, thereby effectively ensuring the dimensional precision of the crucible manufactured by the method.

Description

technical field [0001] The invention relates to the field of inorganic non-metallic materials, in particular to a method for manufacturing a silicon nitride bonded silicon carbide ceramic crucible. Background technique [0002] Silicon nitride bonded silicon carbide crucible has a wide range of applications in many fields such as non-ferrous metal smelting, rare earth powder heat treatment, lithium ion battery electrode material synthesis, etc. due to its excellent high temperature strength, thermal shock resistance and chemical inertness. The current methods of making ceramic crucibles mainly include the traditional vibration grouting molding method and the gel casting method developed in the 1990s. In the patent (Application No.: 201010529248.9), Jia Shiheng used vibration casting molding and freezing demoulding method to prepare a silicon nitride bonded silicon carbide large-scale crucible. The main processes disclosed in this patent include batching, molding, drying and ...

AI Technical Summary

Problems solved by technology

But this method has certain defects

First of all, the ceramic green body obtained by gel injection molding has the elasticity similar to rubber, but the rigidity is low. Due to the large size of the crucible green body, it is difficult to control the deformation of the crucible due to the weight of the crucible before it is completely dried; Secondly, during the process of vacuuming and degassing the quartz ceramic slurry, due to the rapid discharge of air, it is easy to cause the gelation of the slurry to proceed in advance, so the curing time is difficult to control; thirdly, the fused silica crucible is made by gel injection molding , it usually needs to be dried under high humidity and room temperature for a long time until the green body no longer shrinks significantly, and then it can be dried at a higher temperature, so the drying cycle is very long