Interface Behavior of Brazing between Zr-Cu Filler Metal and SiC Ceramic

Bofang Zhou,Taohua Li,Hongxia Zhang,Junliang Hou

doi:10.3390/cryst11070727

Bofang Zhou, Taohua Li + Show 2 more

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https://doi.org/10.3390/cryst11070727

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Abstract

The interface behavior of brazing between Zr-Cu filler metal and SiC ceramic was investigated. Based on the brazing experiment, the formation of brazing interface products was analyzed using OM, SEM, XRD and other methods. The stable chemical potential phase diagram was established to analyze the possible diffusion path of interface elements, and then the growth behavior of the interface reaction layer was studied by establishing relevant models. The results show that the interface reaction between the active element Zr and SiC ceramic is the main reason in the brazing process the interface products are mainly ZrC and Zr2Si and the possible diffusion path of elements in the product formation process is explained. The kinetic equation of interfacial reaction layer growth is established, and the diffusion constant (2.1479 μm·s1/2) and activation energy (42.65 kJ·mol−1) are obtained. The growth kinetics equation of interfacial reaction layer thickness with holding time at different brazing temperatures is obtained.

Highlights

SiC ceramic material has the advantages of high nuclear fuel consumption and difficult to react with hot water vapor at high temperature; it is very likely to replace zirconium alloy as the fourth generation of nuclear fuel cladding material [1]
This paper focuses on the brazing mechanism of Zr-Cu filler metal and SiC ceramic, which lays a theoretical foundation and technical guidance for the development of brazing filler metals and the research of brazing technology
The SiC ceramic and Zr-Cu filler metal were processed into shapes 20 × 10 × 10 mm3 and 20 × 10 × 0.2 mm3, and polished with a 2000# diamond grinding disc and cleaned with an ultrasonic wave in acetone for 30 min

Summary

Introduction

The joining methods of SiC ceramic materials mainly include brazing [3,4], diffusion bonding [5,6], reaction bonding [7] and ceramic precursor bonding [8]. Among them, brazing of the SiC ceramic can obtain ideal joints at lower temperatures and shorter times, and is the most possible joining method to realize mass production. It is widely known that the composition and properties of filler metal are the key factors to achieve the brazing effect of SiC ceramics. In terms of high temperature properties, the brazing joint properties of Ag-based and Cu-based filler metals are relatively poor. The joint properties of Au-based filler metal brazing are better, but the cost is high. A joint with the high temperature properties of Ti-based, Ni-based and Co-based filler metals brazing are better.

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