Solid‐State Diffusion Bonding of Carbon–Carbon Composites with Borides and Carbides

Abstract

Solid-state diffusion bonding of carbon-carbon (C-C) composites by using boride and carbide interlayers has been investigated. The interlayer materials used in this study were single-phase borides (TiB, or ZrB,), eutectic mixtures of borides and carbides (ZrB, + ZrC or TiB, + B,C), and mixtures of TiB, + S i c + B4C produced in situ by chemical reactions between B,C, Ti, and Si or between TIC, Si, and B. The double-notch shear strengths of the joints produced by solid-state reaction sintering of B,C + Ti + Si interlayers were much higher than those of joints produced with other interlayers. The maximum strength was achieved for C-C specimens bonded at 2000°C with a 2:l:l mole ratio of Ti, Si, and B,C powders. The reaction products identified in the interlayers, after joining, were TiB,, Sic, and Tic. The joint shear strength increased with the test temperature, from 8.99 MPa at room temperature to an average value of 14.51 MPa at 2000°C.

Effect of temperature and layer thickness on these strengths of carbon bonding for carbon/carbon composites

“…After the conversion of Dr c into corresponding strain De r using YoungÕs modulus, De r was substituted into e r in Eq. (2). The calculation result for the modified residual stress is shown by the dotted line in Fig.…”

“…carbide by chemical reaction between metal and carbon in the substrate C/Cs, followed by the decomposition of the carbide and evaporation of the metal element at elevated temperature. Low bonding strength was, however, reported for this processing route [2]. A SiC bonding layer has been formed by the reaction of the substrate C/Cs and Si.…”

“…Carbon [1,2], SiC [1,3] and other ceramics-based adhesives [4][5][6] have been discussed as high temperature bonding materials between C/Cs. Carbon bonding has been generally formed by the carbonization of a resin bonding layer [1].…”

High-temperature property of carbon/carbon composite joints bonded with ternary Ti–Si–C compound

“…Using boron, refractory borides or carbides as interlayer, Dadras al. [8] and Dadras and Mehrotra [9] investigated the feasibility to join C/C composites by solid diffusion bonding. Those joints can be used at high temperature; however, high joining temperature more than 2173 K was needed during joining process, which made it hard to join large-scale C/C components.…”

R&D of joining technology for SiC components with channel

“…Joining of SiC ceramics has been demonstrated using various techniques including diffusion bonding, brazing bonding with alloy and hot pressing of sinterable SiC powder [5,6]. A method of joining SiC ceramics that satisfies the requirements of mechanical integrity, desirable thermal properties, safety during operation and maintenance or accident is required.…”