one of the major problems facing the aircraft industry is the machining of the engine parts. amongst the numerous parts in a jet engine are intricate parts made of special alloys for high temperature service, namely nickel,chromium and titanium alloys. these alloys are usually very difficult to machine, which creates problems in this respect. the necessity of quality control in each stage of pr...

BACKGROUND Alloys with high nickel content have been increasingly used in dentistry. Alloys have high corrosion rates when exposed to chemical or physical forces that are common intra orally. Titanium is the most biocompatible materials for crowns, fixed partial dentures and implants in the present use, but paradoxically the self-protective oxide film on the titanium can be affected by excessiv...

The development of materials which contain the noble metals for use in high temperature strain gauges is reviewed, with particular emphasis being placed upon work done by the Institute of Precious Metals, in China. Three alloy systems displaying excellent resistance to oxidation and good overall properties when used in high temperature straingauges, are singled out for examination. These are pl...

Background: Orthodontics is a part of dentistry that includes preventive methods and correction of dental irregularities that need to be repositioned by functional and mechanical tools to provide an ideal occlusion and a beautiful face for patients. There are currently four metal arch wires used in orthodontic treatment: stainless steel alloy, cobalt-chromium alloy, nickel-titanium alloy, and b...

Cobalt-Chromium (Co-Cr) alloys are classified as predominantly base-metal alloys and are widely known for their biomedical applications in the orthopedic and dental fields. In dentistry, Co-Cr alloys are commonly used for the fabrication of metallic frameworks of removable partial dentures and recently have been used as metallic substructures for the fabrication of porcelain-fused-to-metal rest...

We present a general model of disorder in Kondo alloys that, under certain conditions, leads to non-Fermi-liquid behaviour. The central underlying idea is the presence of a distribution of local Kondo temperature scales. If this distribution is broad enough, such that there are sites with arbitrarily low Kondo temperatures, a non-Fermi-liquid phase is formed. We analyse thermodynamics and trans...

The behavior of alloys in nitrogen at high temperature is relevant to many industrial applications. Embrittlement due to internal nitride formation is the principal problem encountered in service. In this study, the nitridation resistance of a series of alloys in pure nitrogen at 1093 O C was investigated. For Fe-base, Ni-base, and Co-base alloys the amount of nitrogen absorbed and the nature a...

BACKGROUND The pathogenesis of total joint replacement failure is multifactorial. One hypothesis suggests that corrosion and wear of alloys result in metal ion release, which may then cause sensitization and even implant failure, owing to the acquired immune reactivity. OBJECTIVES To assess cobalt, nickel and chromium(VI) release from, and the metal composition of, failed metal-on-ethylene to...

Some of the component metals of the alloys used for total joint prostheses are toxic and dissolve in the body fluids. It is important to establish how toxic these metals are and to assess the risk of localised tissue necrosis around the prostheses. This has been investigated by incubating primary monolayer cultures of human synovial fibroblasts with various preparations of metals for periods up...

A microstructural study was conducted on 15 cobalt-chromium-nickel alloys of the basic composition 40 Co-30 Ni-30 Cr. The alloys were strengthened by the addition of tantalum and tantalum-rich regions were found at the interdendritic spaces. The increase in Ta concentration caused a decrease in the concentration of the a phase and an increase in the amounts of the a phase. Excessive amounts of ...