| About this Abstract |
| Meeting |
2024 AWS Professional Program
|
| Symposium
|
2024 AWS Professional Program
|
| Presentation Title |
SiC and Nickel-Base Superalloy Dissimilar Joining using Multi-Principal Element Alloy Metal-Matrix Composite Filler |
| Author(s) |
Aaron Wells, Youyang Zhao, Benjamin Schneiderman, Zhenzhen Yu |
| On-Site Speaker (Planned) |
Aaron Wells |
| Abstract Scope |
In the concentrating solar power industry, there is an increasing demand for ceramic-based components connected to metal heat transfer networks for increased efficiency and reduced risks. One of the main technical barriers to achieving such synergy lies in reliably joining ceramic to metal with acceptable mechanical, thermal and chemical stabilities. In this study, a multi-principal element alloy (MPEA) metal-matrix composite (MPEA-MMC) filler was designed and evaluated for joining SiC to Inconel 740H for structural applications at elevated service temperatures. Due to a significant mismatch in coefficients of thermal expansion (CTE) between the two substrate materials, high residual thermal stresses arise upon cooling, leading to crack propagation throughout the ceramic substrate near the joint interface. The core benefits of MPEAs as candidate consumables for dissimilar materials joining are the vast design space to achieve a single-phase random solid solution, their phase stability within a wide compositional range to accommodate complex alloying variations through dilution from both substrates, and promising mechanical properties. Various amounts of carbide powders were added to the MPEA during vacuum furnace brazing for in situ mixing during dissimilar joining. Light optical microscopy (LOM), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were employed to characterize the joint quality and interface microstructures. Slight growth of the carbide powders was observed in the joint region, and a good metallurgical bond was formed at both substrate interfaces. Finite element modeling (FEM) was performed to investigate the impact of carbide powder volume fraction on residual stress control and matched well with the experimental results of 0 to 30% carbide powder additions. Spark plasma sintering process is being further evaluated for improved control of MMC mixing ratio (e.g., up to 80% volume fraction of carbide powders) to achieve greater CTE mismatch control and crack elimination in the SiC substrate. |
| Proceedings Inclusion? |
Undecided |