Method for forming compact TaC coating on surface of graphite base material

Abstract

The invention discloses a method for forming a compact TaC coating on the surface of a graphite base material. The method comprises the following steps: (1) processing and cleaning the graphite base material, and drying the graphite base material in a drying oven for later use; (2) uniformly mixing and stirring TaC powder, sintering aid powder, absolute ethyl alcohol and the metal salt compound toprepare electrophoretic suspension; (3) putting a graphite base material into the electrophoresis suspension, then inserting a positive electrode material into the electrophoresis suspension, enabling the positive electrode material to surround the graphite base material, taking the graphite base material as a negative electrode, inserting an ultrasonic vibration rod, and carrying out electrophoretic deposition; (4) taking the workpiece obtained after electrophoretic deposition out and putting theworkpiece into a drying oven to be subjected to heat treatment; and (5) putting the workpiece subjected to heat treatment into a high-temperature sintering furnace, carrying out sintering in an inert atmosphere in a low-pressure state, and cooling the workpiece to room temperature after sinteringis finished, thereby obtaining the compact TaC coating. The TaC coating prepared by the method is uniform and compact, the preparation process is simple, and the production cost is low.

Description

Technical field [0001] The present invention relates to the field of composite materials, and in particular, a method of forming a dense TAC coating on the surface of the graphite substrate. Background technique [0002] In order to give the wide bandap power device, it must be greatly reduced, especially in terms of the formation of epitaxial layers (epitaxial cost), which accounts for half of the extends of extension wafers (single crystal lining with an epitaxial layer). bottom). CVD-SiC or MOCVD-GaN epitaxial growth conditions are more corrosive than conventional CVD-Si process conditions. And the CVD-SiC epitaxial growth gas system is H 2 -Sih 4 -C 3 Hide 8 The epitaxial growth temperature is as high as 1500-1700 ° C. For ordinary SiC coated graphite trays, it is difficult to use long-term reliable use in such a harsh environment. [0003] Tantalum (TAC) is an important high-strength, corrosion-resistant and chemically stable high-temperature structural material, which melte...

AI Technical Summary

Problems solved by technology

CVD is the mainstream preparation method of TaC coating at present, and the coating is uniform and dense; however, the process technology is difficult and the production cost is high

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