Supercritical fluid process for dewaxing hot-press ceramics

Abstract

A supercritical fluid dewaxing process for hot-pressed ceramics includes mixing the raw ceramic slurry with polar on non-polar mixed paraffine adhesive and low-temp deoxing in supercritical CO2 fluid. Its advantages are short period, and no deformation and crack.

Description

technical field [0001] The invention belongs to the technical category of ceramic material production, and in particular relates to a supercritical fluid dewaxing method capable of obtaining a ceramic blank in a short period of time without deformation and defect. technical background [0002] The precision molding of ceramic parts with complex shapes has been a concern of ceramic preparation science for more than ten years. As a near-net-size molding technology, ceramic hot die-casting not only has the advantages of forming complex shape products, dimensional accuracy, and high surface finish, but also has the characteristics of high automation and adaptability to large-scale production. For ceramic hot die-casting, it is generally necessary to add A large amount of paraffin wax with a volume ratio of 30% to 60% is used as an organic carrier, so the organic matter in the green body must be removed by heating before sintering, that is, dewaxing. The traditional dewaxing met...

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Problems solved by technology

At this stage, the green body has low strength after being softened by heat and is prone to deformation. The dewaxing rate is directly controlled by the temperature, and the heating rate is slow, which is very time-consuming; Small molecules will generate high pressure in the green body because they cannot be eliminated, and various defects such as bubbling, swelling, cracking, delamination, and deformation will occur in the green body, which will not only reduce the yield of the entire process, but also further affect the green body. well sintered