Ultrafast sintering method for preparing carbon nano-tube reinforced ceramic

Abstract

The invention relates to a preparation method of carbon nanotube reinforced ceramic. An ultra-fast sintering method for preparing the carbon nanotube reinforced ceramic is characterized by comprising the following steps: enwrapping a material blank to be sintered with a solid combustion reactant; firing the reactant to allow a high-temperature combustion reaction; transmitting heat of the high-temperature reaction to the material blank to be sintered so as to rapidly heat the material blank to be sintered to a high temperature; and applying mechanical pressure on the high-temperature material blank to be sintered to obtain the compact carbon nanotube reinforced ceramic. The method can provide an ultra-fast temperature rise speed (1600-2900 DEG C / min) for sintering ceramic, a maximum temperature is 1450 DEG C-2620 DEG C, and the ceramic sintering can be completed in a very short time (1-2min), which effectively avoids damage to the carbon nanotube; meanwhile, the higher mechanical pressure (100-500MPa) applied at the high temperature is beneficial to forming a good interface between the carbon nanotube and a ceramic substrate, thus effectively improving fracture toughness of the ceramic material.

Description

technical field [0001] The invention relates to a preparation method of carbon nanotube reinforced ceramics. Background technique [0002] Carbon nanotubes (CNTs) have been a research hotspot in the field of nanomaterials since their discovery because of their superior mechanical, thermal, and electrical properties. The average elastic modulus of single-walled carbon nanotubes is 1.25TPa, and the average elastic modulus of multi-walled carbon nanotubes is between 270-950GPa. The excellent mechanical properties make them have great development potential in the field of composite materials. In recent years, carbon nanotubes have been widely used as reinforcing phases of polymer materials and ceramic materials. Research on carbon nanotube-reinforced ceramics by scholars at home and abroad shows that carbon nanotubes can improve the mechanical properties of ceramic materials, but their toughening effect has not made breakthroughs. There are three problems to be solved in the p...

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Problems solved by technology

Ordinary radiation heating conditions, such as hot pressing sintering, have a slow heating rate (10-50°C / min) and a long duration of high temperature. It has been reported that the damage to carbon nanotubes is serious, and the fracture toughness of ceramics is basically not improved; SPS ( Spark plasma sintering) sintering can prevent carbon nanotubes from being damaged because of its fast heating rate (100-600°C / min), low sintering temperature, short duration of high temperature, and less damage to carbon tubes. G-D Zhan et al. used this technology to prepare composite ceramics with a 2-fold increase in fracture toughness; however, the ceramics prepared by Wang, X et al. using the same method had no significant improvement in performance compared to pure alumina ceramics; according to D-T Jiang et al. According to the latest report of people, when sintering with SPS, when the sintering temperature exceeds 1150 ° C, the carbon tubes also begin to break down

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