This project supports collaborative research by Dr. Darryl Butt, Materials Science and Engineering Department, Boise State University, Boise, Idaho in collaboration with Dr. Madiha Shoeib, Central Metallurgical Research & Development Institute, Helwan, Egypt. They plan to study the corrosion of ceramic-metal joining. A novel transient liquid phase (TLP) joining process developed by a member of the U.S. group has successfully joined ceramics. However, ceramics are often only useful when joined with dissimilar materials such as metals. The objective here is to determine the effectiveness of the novel TLP process in joining ceramics to metals. The U.S. group will fabricate joints between the high temperature perovskite La0.9Ca0.1FeO3 and various metal alloys such as NiAl, Hastalloy X, Inconel 625, 316L Stainless Steel, and HT-9 Stainless Steel. They will study the kinetics and thermodynamics of the joining process and perform mechanical testing and surface characterization of the joints. The Egyptian group will perform high temperature corrosion studies, intergranular corrosion studies, stress corrosion cracking studies, and additional surface characterization of the joints. The results will help determine if this method can be applied in an industrial environment such as the petroleum industry, the automotive industry, and the aerospace industry. The development of these novel joints has specific application in gas separations, more specifically environmentally stable perovskite-metal joints is an enabling technology for membrane-based syngas production from natural gas. Currently, during drilling of oil in remote areas such as off shore oil platforms, the Alaskan wilderness, and many countries in Africa, natural gas is flared rather than transported and used, due to the high cost of transporting gas rather than liquid fuels. Conversion of natural gas to liquid fuels via the syngas and Fischer-Tropsch processes would yield environmental and economic benefits. Several groups, including Dr. Butt who has two patents on perovskite compounds, have demonstrated that compounds such as La0.9Ca0.1FeO3 can be used to efficiently separate oxygen from air for subsequent reaction with natural gas over a catalyst to produce CO and H2 (syngas). Proving that durable joints can be produced between perovskites and alloys, would result in an enabling technology with significant economic benefits.
Intellectual Merit: The PIs plan to apply the TLP joining process technique they have developed to join ceramics and metals. They will conduct high temperature corrosion, intergranular corrosion, and stress corrosion cracking studies, in addition to surface characterization of the joints. It is an interesting breakthrough to join stainless steel to ceramics. The research is relevant for the development of knowledge in the field. The proposal could lead to scientific progress with potential applications. The innovative approach could have very promising applications for various structural applications where the two materials (Ceramics and Metals) are desirable because of the inherent and different properties of the two materials. The impact of this proposed work may contribute to the understanding of the ceramic-metal joining and its interface microstructure, mechanical and corrosion behavior.
Broader impacts: The project could lead to better understanding of TLP joining behavior in critical environments. The results could lead to new or improved applications in various industrial fields. The US and Egyptian scientists have excellent and complementary qualifications. U.S. Post doctoral researchers and students will be involved in the project. This project is being supported under the US-Egypt Joint Fund Program, which provides grants to scientists and engineers in both countries to carry out these cooperative activities.
