Solid oxide fuel cells are high temperature electrochemical devices for direct conversion of fuel and oxidant to electricity and heat. The high temperature and dual atmosphere creates challenges for the materials in solid oxide fuel cell stacks. In this thesis SOFC stack materials were studied and developed. SOFC stacks are assembled at room temperature, then heated up, conditioned and operated...

Ni-Hard4 white cast iron is excellent wear resistant material and has been widely used in wearaffected equipment operated under extreme conditions, such as in mineral processing, cement, copper and iron manufacturing. In this study the effect of titanium addition (1.2, 0.7 and 0.2 wt.%) to the Ni-hard 4 cast iron with the nominal composition of Si= 1.5%, Mn=0.5%, C=3%, P=0.05%, S= 0.05%, Mo= 0....

Tape brazing constitutes a cost-effective alternative surface protection technology for complex-shaped surfaces. The study explores the characteristics of high-temperature brazed coatings using cobalt-based powder deposited on stainless-steel substrate in order to protect parts subjected hot temperatures wear-exposed environment. Microstructural imaging corroborated with x-ray diffraction analy...

New methods of diffusion metallization AISI W1-7 steel have been developed. The paper proposes a comparative analysis the properties and characteristics after three chemical heat treatment: nitriding, nitrogen titration by physical deposition from gas phase, chromium plating with subsequent titanium alloys. results are presented as comprehensive coatings: metallographic, micro-X-ray spectral, X...

In this study, the changes in microstructure of HP-Nb cast heat resistant steel after 8 years of service at high temperatures were investigated. Study of microstructure using optical microscopy (OM) and scanning electron microscopy (SEM) equipped with an energy dispersive spectrometry (EDS) showed that the microstructure of this steel in as-cast condition includes an austenitic matrix, and that...

In this research work a series of tests were conducted in order to determine flank wear and cutting force FY on hard AISI 440 C martensitic stainless steel and SCM 440 alloy steels. The operating parameters are cutting speed, feed rate and a constant depth of cut to investigate the flank wear and cutting force. No cutting fluid was used during the turning process. The cutting tool used was CBN ...

Wear resistance of brake discs has a significant effect on the safety high-speed trains. In this work, rolling–sliding wear low-carbon martensitic disc steel was investigated. The microstructure evolution and mechanical properties from worn surface to matrix were analyzed promote parameters for application steel. results indicated that ratcheting strain zone formed at under asymmetric cycling l...

Surface texturing-plasma nitriding duplex treatment was conducted on AISI 316 stainless steel to improve its tribological performance. Tribological behaviors of ground 316 substrates, plasma-nitrided 316 (PN-316), surface-textured 316 (ST-316), and duplex-treated 316 (DT-316) in air and under grease lubrication were investigated using a pin-on-disc rotary tribometer against counterparts of high...