A kind of spark plasma sintering preparation method of cermet fuel pellets

Abstract

The invention belongs to the technical field of nuclear fuel preparation, and relates to a method for preparing CERMET fuel pellets by discharge plasma sintering. The preparation method comprises the following steps in turn: (1) depositing a metal layer on the surface of ceramic phase particles by vapor deposition process; (2) putting metal phase powder and grinding balls into a ball mill pot for high-energy ball milling, and the powder after ball milling is After the metal phase powder is transferred into the atmosphere furnace, the heating is turned on, and the high-purity H is continuously introduced. 2 (3) Mix the ceramic phase powder processed by vapor phase deposition with the metal phase powder processed by high-energy ball milling and reduction treatment with a three-dimensional motion mixer to obtain SPS sintering raw materials; (4) Put the SPS sintering raw materials into The SPS mold is placed in the sintering furnace, vacuumed and sintered. By using the preparation method of the invention, the continuous metal phase and the uniform distribution of ceramic phase particles in the metal phase matrix can be realized under the premise of a relatively low volume ratio of the metal phase, and the sintering temperature of the core block can be further reduced.

Description

technical field [0001] The invention belongs to the technical field of nuclear fuel preparation, and relates to a method for preparing CERMET fuel pellets by discharge plasma sintering. Background technique [0002] Ceramic refractory metal composite fuel (CERMET fuel) has the advantages of high operating temperature, high burnup, high radiation stability, high fission product storage capacity, etc., and it has inherent safety. ) also maintains a subcritical state. [0003] Optional ceramic types in CERMET fuel include UO 2 , UN, UC, etc., optional refractory metals include Ni, W, Mo, Re, etc., which can produce UO 2 -Ni, UO 2 -W, UN-W, UC 2 -C and other series of composite pellet components. The following table is a list of selected CERMET fuel components in various development programs in the United States. [0004] Table 1 Selection of CERMET fuel components in various development programs in the United States [0005] [0006] In the tests of these research pro...

AI Technical Summary

Problems solved by technology

Another problem with the Tucker method is that in order to achieve a high pellet density (>99% of the theoretical density of the pellet), the sintering temperature must also reach 1850°C

[0013] In summary, CERMET fuel has not been extensively studied internationally, and its most mature manufacturing process is vapor deposition hot isostatic pressing, but this method is aimed at UO 2 -W is developed with a single component and cannot be applied to CERMET pellets with all components

For example, the sintering temperature of this method is very high, so it cannot be applied to the preparation of pyrolysis UN-W fuel pellets

In order to meet the needs of a wider range of CERMET fuel production in the future, the development of new general-purpose production technologies is a must, among which SPS technology is an optional direction. The main problem is that the metal phase and the ceramic phase are evenly mixed when the content of the metal phase is low. properties and preparation of high-density pellets

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