The original protocol for implant prosthesis recommends the use of a gold framework for acrylic and ceramic prosthesis. However, due to its high cost, the use of alternative alloys is desired. This study compares the marginal accuracy of pre-made cylinders versus plastic cylinders cast with two different base metal casting alloys. Five samples each of (1) plastic cylinder cast in cobalt-chromiu...

The objective of the present work is to study the casting characteristics of various A1-Li alloys, which include fluidity and strengths of the alloys and their interaction with cast molds. Materials investigated are Al-Li-Mg and Al-Li-Cu-Mg alloys with Li content of 2.5 wt%. The results show that sand molds with resin binders are good for A1-Li casting. Ceramic coatings can further reduce the m...

The most notable method of infection from Escherichia coli O157 (E. coli O157) is through contaminated food products, usually ground beef. The objective of this study was to evaluate seven cast copper alloys (61 to 95% Cu) for their ability to reduce the viability of E. coli O157, mixed with or without ground beef juice, and to compare these results to those for stainless steel. E. coli O157 (N...

STATEMENT OF PROBLEM Cobalt-chromium (Co-Cr) alloys have been widely used for metal-ceramic fixed prostheses and can be fabricated using conventionally cast or new computer-aided technology. However, the effect of different manufacturing methods on the metal-ceramic bond strength needs further evaluation. PURPOSE The purpose of this in vitro study was to evaluate the metal-ceramic bond streng...

master moulds are used to cast copper anode moulds. these iron moulds are made of grey or nodular cast irons. according to desirable properties of ductile irons, it was expected that ductile cast iron moulds could have performed their nominal life. but in service, these moulds have not performed their nominal life and they have experienced premature failures due to warping and cracking. also gr...

The effect of heat treatment and alloying elements of copper and tin on the microstructure and mechanical properties of austempered ductile cast iron alloys is investigated. The austenitizing temperature of 890°C, the isothermal transformation (austempering) temperatures of 285, 335 and 375°C, and austempering times of 15, 30, 75 and 150 minutes are studied. The alloying elements of copper and ...

The segregation of the elements during solidification and the direct formation of destructive phases such as Laves from the liquid, result in in-homogeneity of the cast structure and degradation of mechanical properties. Homogenization heat treatment is one of the ways to eliminate destructive Laves from the cast structure of superalloys such as 718Plus. The collected data presents the effect o...

Titanium alloys are receiving increasing research interest for the development of metallic stent materials due to their excellent biocompatibility, corrosion resistance, non-magnetism and radiopacity. In this study, a new series of Ti-Ta-Hf-Zr (TTHZ) alloys including Ti-37Ta-26Hf-13Zr, Ti-40Ta-22Hf-11.7Zr and Ti-45Ta-18.4Hf-10Zr (wt.%) were designed using the d-electron theory combined with ele...

Shot peening is known to improve the fatigue performance of structural metallic materials. The improvement in fatigue life is derived primarily from compressive residual stresses that are introduced into the near-surface of the components and which hinder crack initiation and growth. Magnesium alloys are finding increasing use in automotive applications, but their relatively low strength means ...

Aiming at establishing a reliable welding technique for magnesium alloys, the laser weldability of different types of magnesium alloys has been investigated using a high-brightness disc laser. It was found that high quality joints could be fabricated in the case of wrought type alloys when a certain defocusing level was optimized for the employed high-brightness laser beam of the newly develope...