Low Pressure Joining of SiCf/SiC Composites Using Ti3AlC2 or Ti3SiC2 MAX Phase Tape

Abstract

Tyranno SA (SiC-polycrystalline fiber, Ube Industries Ltd.) shows excellent heat-resistance up to 2000 o C with relatively high mechanical strength. This fiber is produced by the conversion process from a raw material (amorphous Si-Al-C-O fiber) into SiCpolycrystalline fiber at very high temperatures over 1500 o C in argon. In this conversion process, the degradation reaction of the amorphous Si-Al-C-O fiber accompanied by a release of CO gas for obtaining a stoichiometric composition and the subsequent sintering of the degraded fiber proceed. Furthermore, vaporization of gaseous SiO, phase transformation and active diffusion of the components of the Si-Al-C-O fiber competitively occur. Of these changes, vaporization of the gaseous SiO during the conversion process results in an abnormal SiC-grain growth and also leads to the non-stoichiometric composition. However, using a modified Si-Al-C-O fiber with an oxygen-rich surface, vaporization of the gaseous SiO was effectively prevented, and then consequently a nearly stoichiometric SiC composition could be obtained.

An Overview of Parameters Controlling the Decomposition and Degradation of Ti-Based Mn+1AXn Phases

“…On the other hand, Liu and co-workers [56] took advantage of partial decomposition in fabricating Ag/Ti 3 AlC 2 composites with enhanced mechanical properties through the formation of Ag (Al) solid solution in the interfacial zone between Ag and Ti 3 AlC 2 . A similar concept was utilized by Septiadi et al [57] in joining SiC f /SiC composites with thin tapes of Ti 3 AlC 2 or Ti 3 SiC 2 . Again, strong joining was successfully accomplished through solid-state diffusion bonding courtesy of partial decomposition of the tapes.…”

Processing of MAX phases: From synthesis to applications

“…Joining is particularly challenging for ceramic 287,288 Decomposition might promote a strong joint between SiC parts since a uniform, strong, and dense TiC/SiC interface without cracks is obtained. 289 The residual thermal stress of SiC/Ti 3 SiC 2 /SiC joints were also calculated by finite element analysis, showing strong stress reduction and high bending strength (157 MPa) when the system is post-annealed at 900°C. 290 MAX phases can be also joined to metallic components, although some reactions at the interfaces have been detected.…”

“…However, at higher temperatures, 1500°C‐1900°C, 286 the strength increases to almost 170 MPa due to a chemical reaction at the interface and the partial or complete decomposition of Ti 3 SiC 2 287,288 . Decomposition might promote a strong joint between SiC parts since a uniform, strong, and dense TiC/SiC interface without cracks is obtained 289 . The residual thermal stress of SiC/Ti 3 SiC 2 /SiC joints were also calculated by finite element analysis, showing strong stress reduction and high bending strength (157 MPa) when the system is post‐annealed at 900°C 290 …”

Synthesis of Ti3SiC2 coatings onto SiC monoliths from molten salts

“…The reaction of titanium and carbon fibres in molten salts yields also high-quality TiC coatings [24]. Due to its high temperature stability, the Ti3SiC2 phase could be an interesting interphase of the SiCf/SiC composites [25][26][27] and for assembling SiC-based materials [28][29][30][31]. In both cases, it is necessary to obtain a controlled coating on SiC materials.…”