BACKGROUND Cobalt chromium coronary stents are increasingly being used in percutaneous coronary interventions. There are, however, no reliable data about the characteristics of unfolding and visibility of this stent alloy in vivo. The aim of this study is to compare cobalt chromium coronary stents with conventional stainless steel stents using intracoronary ultrasound. METHODS Twenty de novo ...

A new ultra-high strength steel with a fully austenitic microstructure and twinning-induced plasticity (TWIP) effect has been developed. TWIP gives this good combination of high over 1000 MPa ductility 35%. This chromium content, which increases its corrosion resistance. By combining cold rolling annealing, the achieved very fine an average grain diameter 2.85 µm. could be used for structural a...

This paper investigates the tribological behavior of 100Cr6 steel pin running against sintered steel bearing material used in hermetic compressors. Tests were conducted under dry and starved lubrication sliding conditions in air at room temperature. Although porous structure acts as crack initiation sites thus limiting the wear resistance of sintered iron in dry sliding conditions under high co...

ni-w coatings, compared to pure nanocrystalline ni, exhibit higher hardness and wear resistance. in some cases, these coatings are considered as environmental friendly alternatives for hard chromium coating. till now, most of ni-w coatings have been produced by direct current electrodeposition from alkaline baths. in this study square pulse current was used for deposition of ni-w precipitates f...

In this study, tungsten oxide coatings with 13 and 75 at% of oxygen were prepared by DC reactive magnetron sputtering from a pure W target in an Ar+O2 atmosphere. The coating hardness (H) decreased with increasing oxygen content from 25 to 7.7GPa. The values of H/E ratio were 0.08 and 0.07 for W87O13 and W25O75, respectively. The tribological measurements were carried out on a pin-on-disc tribo...

Ultra-high strength steels are widely utilized in many applications operating harsh abrasive wear conditions. For instance, the machineries used mining and mineral handling or agricultural sector require robust, but cost-effective wear-resistant materials. Steels provide excellent combination of mechanical properties usability. This study encompasses testing an experimental medium-carbon press-...

In this study, the effect of deposition regime on the wear behavior of VK8 coating applied to 1.2344 tool steel by electro spark method (ESA) was investigated. After sample preparation, the coating with high and low regime was applied. To assess the wear behavior, the pin on disk test method according to ASTM G99-04, was used. For surveying surface morphology and cross section of the coating as...

We investigated the wear characteristics and clinical performance of four different total hip joint articulations in 114 patients. Wear and migration was measured by roentgenstereophotogrammetric analysis at five years or at the last follow-up. The mean annual wear was 0.11 mm for a stainless steel/Enduron articulation, 0.34 mm for stainless steel/Hylamer cup, 0.17 mm for zirconium oxide cerami...

With the continuous expansion of application field low alloy wear-resistant steel, higher processing plasticity and toughness are prioritized on basis ensuring strength hardness. In this article, a steel Hardox400 was studied: by adding mass fraction 0.0030% rare earth cerium as microalloying treatment, pilot scale simulation carried out using vacuum induction furnace four-high reversible labor...