BACKGROUND/AIM Metal-ceramic bond strength and alloys' elastic modulus clearly determine the potential of alloy application, because the ceramic integrity during mastication depends on these two characteristics. The aim of this study was to evaluate metal-ceramic bond strenght and elastic modulus of cobalt-chromium alloys in making porcelain-fused-to-metal restorations, regarding the applicatio...

In order to obtain the high-performance composites with high density, the influence of additional ultrasonic vibration on the infiltration of molten aluminum alloy (ASTM A336.0) into nickel porous preform by low-pressure and pressureless casting was investigated. There was no effect of ultrasonic vibration on infiltration distance under pressureless casting because of presence of surface oxide ...

Diffusion characteristics of iron and nickel atoms were investigated using radioactive isotopes method in phase-hardened metastable iron-nickel Fe-31.7%Ni-0.06%C alloy with nanofragmented structure. It has been found that diffusion mobility of nickel and iron atoms in reverted austenite of Fe-31.7%Ni-0.06%C alloy significantly increases as the result of multiple γ-α-γ martensitic transformation...

Article history: Received 28.3.2013 Received in revised form 26.4.2013 Accepted 29.4.2013 Aluminum matrix composites containing 55% SiC particle reinforcing phase/SiC reinforcement phase particle and Kovar alloy 4J29 were chosen as the base metals. After nickel plating on the surface of SiCp/Al, two kinds of materials were soldered together by using Zn-Cd-Ag-Cu as the filler metal and ZnCl2 as ...

We investigated the strengthening mechanism of laser shock processing (LSP) at high temperatures in the K417 nickel-based alloy. Using a laser-induced shock wave, residual compressive stresses and nanocrystals with a length of 30-200 nm and a thickness of 1 μm are produced on the surface of the nickel-based alloy K417. When the K417 alloy is subjected to heat treatment at 900 °C after LSP, most...

The effect of prior air exposure on rupture life of superalloys is reported. Oxygen is identified as a damaging species leading to severe losses in both rupture life and ductility. Similar embrittlement is observed in pure nickel and a mechanism is proposed in terms of reduced grain boundary mobility. Two cobalt base alloys and an oxide dispersion strengthened nickel base alloy do not embrittle...

The aim of this study was to evaluate the allergenic potential of orthodontic brackets, comparing the cutaneous sensitivity provoked by metals present in conventional metallic brackets to that provoked by brackets with a low concentration of nickel, known as "nickel-free". A sample was selected from 400 patients undergoing treatment in the orthodontic clinic of the Pontifical Catholic Universit...

We report on the first case in Ireland of ureteric stenting with shape-memory alloy nickel-titanium (Memokath 051) stent in relieving malignant ureteric obstruction. Successful drainage was achieved and the patient required no further intervention indicating a clear place for these stents in the long-term management of malignant ureteric strictures. The use of ureteric double-J stenting in the ...

This study was conducted to evaluate the biocompatibility of titanium-nickel shape memory alloy used as a medical implant material. The authors carried out the following electrochemical corrosion test and in vivo and in vitro biological tests for the alloy and some metal and alloys clinically used previously to compare the intensities concerned with the biological reactions, that is, (1) anodic...

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...