The start of melting as well as the melting range in WC-Co and WC-Ni hardmetals is significantly influenced by the alloy gross carbon content as well as by additives (V, Cr). Both Vanadium and Chromium significantly lower the start of melting but also broaden the melting range, in particular at low carbon content (formation of M6C-phases). As a result, a certain temperature range can be defined...

The causes of mechanical failure of five noncemented porous-coated components were studied. There were two cobalt-chromium alloy and three titanium alloy implants which fractured after 12 to 48 months. The implants included one acetabular component, and one femoral condylar, one patellar and two tibial components. Examination of the fractured surfaces revealed fatigue to be the mechanism of fai...

The ferrochrome alloy is produced by electric arc melting of the mineral chromite (FeCr2O4). It is largely used for the production of stainless steels. Increasing the amount of chromium content in the steel allows for increased corrosion and oxidation resistance. Other alloying elements, such as nickel (Ni) or molybdenum (Mo), aid in making the steel more passive and increasing its stainless pr...

The 700 °C power plants currently under development will utilize Ni-base alloys such as alloy 617 for components to be operated at temperatures >650 °C. Due to economic reasons for components or parts of components which are subjected to temperatures <650 °C, 2% Cr or 9-12% Cr steels is used, depending on the required mechanical properties. This makes the dissimilar joining of Ni-base alloys an...

The Clinical and Angiographic analysis with a Cobalt Alloy Coronary Stent (Driver) (CLASS) study was a prospective, nonrandomized, multicenter study designed to assess the safety and efficacy of a cobalt-chromium alloy-based stent in patients with stable or unstable angina pectoris. A total of 203 lesions were treated in 202 enrolled patients. The percentage of major adverse cardiac event-free ...

Two TaC-strengthened cobalt-based alloys, with compositions Co-10Cr-0.25C-4.4Ta and Co-10Cr-0.5C-8.7Ta (wt.%) underwent Cr-deposition by pack-cementation, followed by heat-treatment to allow Cr diffusing deeper in their sub-surface. Thereafter they were tested for 50 hours at 1200°C in a thermobalance. These alloys were successfully enriched in chromium, with a maximal content on surface of abo...

BACKGROUND For success of any indirect metal restoration, a strong bond between cement and the intaglio surface of metal is imperative. The aim of this study is to evaluate and compare the effect of different surface treatment on the tensile and shear bond strength of different cements with nickel-chromium alloy. MATERIAL AND METHODS 120 premolars were sectioned horizontally parallel to the o...

This study compared vertical and passive fit of one-piece cast frameworks made with 3 different materials: commercially pure titanium (CP Ti - G1), cobalt-chromium alloy (Co-Cr - G2) and nickel-chromium-titanium alloy (Ni-Cr-Ti - G3). Fifteen frameworks were obtained simulating bars for fixed prosthesis in a model with 5 implants. The passive and vertical fit of the framework interface was meas...

Introduction: Stainless steel alloy used in orthodontics has elements such as iron - magnesium and chromium , which may be released due to corrosion in the mouth . The aim of this study was to evaluate the changes of these elements in the saliva of patients undergoing fixed orthodontic treatment. Methods: In a clinical study with simple non- random sampling , 1ml saliva of 11 patients (7 fem...

Microstructural and electrical properties of Cu-chromium alloy (Cu-Cr) dispersed with vapor-grown carbon fiber (VGCF) prepared by powder metallurgy (P/M) process have been investigated. Cu-0.7 mass% Cr pre-alloyed powder (Cu-Cr) made by water atomization process was used as raw materials, which contained solid solute Cr elements in Cu matrix. The alloy powder coated with un-bundled VGCF by usin...