Papers by Keyword: Titanium Coatings

Abstract: Titanium is widely used for medical purposes. It related to bone repair because of its favorable mechanical properties and biocompatible ability to osseointegrate in host bone tissue. A good and lasting connection of the implant with the bone tissue is possible when there are sufficient conditions for the bone to grow into the pores of the material, therefore the use of a porous titanium coating may be helpful in solving this problem. In this paper, shrouded plasma spray is used to produce low oxide containing titanium coatings and lower the cost as titanium is a very reactive metal at high temperatures. A solid conical shroud was designed for plasma spray. The titanium coatings were assessed by scanning electron microscopy and energy dispersive X-ray spectroscopy. An analysis in microstructure had been carried out. The results showed that the shroud attachment played an important role in protecting the titanium particles in flight during the process of plasma spraying. An enhanced microstructure with moderate porosity in the titanium coatings plasma sprayed with the shroud was observed. The reduction in air entrainment with the shroud resulted in a good heating of the particles. The plasma-sprayed titanium coating was mainly composed of α-Ti with a low quantity of TiO.

Abstract: In the Caspian region, the Tengiz oil field has a high content of sulfur, salts and mechanical impurities, which contribute to the rapid deterioration of equipment. The use of titanium alloy allows reducing corrosion wear 2-3 times. Based on the analysis of the design of the slide gate valve, the most exposed parts were identified, which were replaced by Grade 5 titanium alloy. Bench tests of the slide gate valve were put into operation. Laboratory work was carried out to apply titanium-based coatings to steel samples. The result was a structure with a microhardness of 730-810 HV sufficient to protect it against corrosion wear.

Abstract: Titanium and its alloys are often used as key materials for corrosion protection. A promising approach to optimize both mechanical properties and corrosion resistance is the use of coating technologies. In this paper, shrouded plasma spray was used as a useful technology to produce low oxide containing titanium coatings. A solid shroud was used to plasma spray titanium coatings to reduce the oxide content. The titanium coatings were assessed by optical microscope, scanning electron microscopy and Vickers microhardness testing. The results showed that the shrouded titanium coatings exhibited an enhanced microstructure. The presence of the shroud and shroud gas flow led to a significant reduction in coating porosity because the reduction in air entrainment with the shroud resulted in better heating of the particles. The shrouded titanium coatings had a lower value of Vickers microhardness and a relative lower standard deviation than the air plasma sprayed titanium coatings.

Abstract: Biomaterials with good biocompatibility and anti-bacterial property were becoming attractive to researchers, so we used the chemical method to produce anti-bacterial vacuum plasma sprayed titanium coatings and studied In vitro bioactivity, cytotoxicity and blood compatibility of the anti-bacterial coatings in this paper. In order to evaluate the bioactivity of the treated titanium coatings, the coatings were immersed in simulated body fluid (SBF). The treated titanium coatings showed good bioactivity in this experiment. Two different methods were used to assess the cytocompatibility of the treated titanium coatings. One was extract test; the other was direct contact test. The results indicated that cells spread and adhered well on the coatings. The blood compatibility of the coatings was evaluated by haemolysis ratios. The hemolysis ratios of the coatings were below 2%, indicating of nonhemolysis for the coatings.

Abstract: Insulated rail joint assemblies provide electrical insulation between two sections of rail for signalling purposes. In this work, rail steel was successfully bonded to PSZ ceramic using an active brazing technique. In order to increase the wettability of the PSZ ceramics, titanium coating was deposited on the ceramic surface using a filtered arc deposition system. A filler metal called BVAg-18 (60%Ag-30%Cu-10%Sn) was used and the joining was performed at a temperature of 750 °C. Bonding between partially stabilised zirconia and rail steel with BVAg-18 filler metal was not achieved using a standard brazing method. Bonding did occur with the BVAg-18 filler metal using the advanced brazing technique of active metal brazing, with best results obtained using a brazing temperature of 750oC and a dwell time of 10 minutes. The microstructure of the coating and joint interface were characterised by XRD, SEM and EDS.