PURPOSE The purpose of this study was to compare the mechanical properties of beryllium-free nickel-chromium (Ni-Cr) dental casting alloy before and after each porcelain firing cycle (once fired, twice fired, and thrice fired) and to relate these properties to the microstructural changes and changes in X-ray diffraction patterns of Ni-Cr alloy that occur after each porcelain firing cycle. MAT...

As an analogy to nickel-based superalloys, ferritic superalloys based on Fe-Al-Cr-Ni-Ti are proposed for high-temperature applications, especially for fossil-energy power systems. Integrated computational tools will be employed to investigate thermodynamic, kinetic, and meso-scale properties of the proposed alloy systems. Meanwhile, selected microstructural attributes in representative model fe...

Bunched and multi-circularly wrapped carbon nanotubes (CNT) are observed to grow on alloy substrates based on iron group metals and copper by a microwave enhanced hot-filament method with a dilute gas of ammonia at a proper RF self-bias. The grown size of CNTs embodied in the grain sizes of conducting bulk alloy catalysts such as Cu-Ni, Cu-Fe, Cu-Co, and Cu-Ni-Fe-Co are controlled by a precurso...

AIMS The aims of this study were to investigate the influence of commercially pure titanium (PTi) and titanium-aluminum-vanadium (Ti-6Al-4V) alloys (TiA) on the final shade of low-fusing porcelain bonded to them and to compare the shade changes with those of three conventional metal-ceramic systems. METHODS AND MATERIALS A titanium casting unit was used to cast PTi and Ti-6Al-4V alloy specime...

We measured the synchrotron-radiation (SR)-based Mössbauer spectra of Ni-based nanoparticles with a hexagonal structure that were synthesised by chemical reduction. To obtain Mössbauer spectra of the nanoparticles without (61)Ni enrichment, we developed a measurement system for (61)Ni SR-based Mössbauer absorption spectroscopy without X-ray windows between the (61)Ni84V16 standard energy alloy ...

The physical-mechanical properties of Ti-Ni-Ta and Ti-Ni-Ta-Si-based surface alloys ~1 μm thickness synthesized on the NiTi substrates by additive thin-film electron beam method were investigated. effect these functional composite systems [Ti-Ni-Ta alloy/TiNi substrate] [Ti-Ni-Ta-Si was explored. It established that Ti-Ni-Ta-Si based alloy with an amorphous structure is characterized higher gra...

STATEMENT OF PROBLEM The increase in the use of metal-ceramic restorations and a high prevalence of porcelain chipping entails introducing an alloy which is more compatible with porcelain and causes a stronger bond between the two. This study is to compare shear bond strength of three base-metal alloys and one noble alloy with the commonly used VMK Master Porcelain. MATERIALS AND METHOD Three...

The anisotropic, heterogeneous and coarse granular structures of austenitic stainless steel welds lead to important disturbances of the ultrasonic propagation: beam skewing and splitting, attenuation, backscattering and spurious echoes. These disturbances have been studied by EDF R&D for a few years in order to improve the ultrasonic NDT in nuclear applications. In particular, a methodology for...

The electrical and structural properties of Hf/Al/Ni/Au (20/100/25/50 nm) ohmic contact to n-GaN are reported in this study. Specific contact resistivities of Hf/Al/Ni/Au based contacts have been investigated as a function of annealing temperature and achieve the lowest value of 1.09×10 Ω·cm after annealing at 650 C in vacuum. A detailed mechanism of ohmic contact formation is discussed. By usi...

Components made of alloys with a magnetic shape memory (MSMA) are not commonly used in industrial systems or prototype solutions. The reasons behind this include the cost and implementation difficulties attached to MSMA alloys synthesis technology. The article presents the results of a prototype actuator in which the active element is a rod made of Ni-Mn-Ga alloy and with dimensions of 2x1x20 m...