Titanium alloy

The possibility of producing titanium alloy Ti ? 6Al ? 4V with minimal residual porosity from mixtures of elemental powders by the method of pressing and sintering without hot deformation during or after sintering was investigated. Various powder mixtures based on titanium and titanium hydride with alloying additions of either elemental powders having different particle sizes, or master alloys, were studied. It was shown that the synthesis of Ti ? 6Al ? 4V from mixtures of titanium hydride and master alloys is optimal with respect to the attainment of high relative density. In this case the sintered material has density up to 99%, homogeneous microstructure with relatively small (100-120 µm) ß-phase grains, and a low concentration of impurities, in particular oxygen, which provide a high level of mechanical properties s(ten = 970 MPa, d = 6%).

Nowadays, titanium alloy is widely used as biomaterials due to good corrosion resistance and excellent biocompatibility. However, some of these materials would like to be a hydrophobic surface to avoid the platelet adhesion. One of the most effective methods to solve this problem is plasma treatment. Therefore,
the aim of this study is to design and fabricate plasma generator for surface modification of biomaterials. In this study, the borosilicate glass is used as a plasma chamber in the vacuum systems. The electrical circuit is also designed as a frequency source. From the calculation, the designed plasma chamber can resist compressive stress up to 70 MPa. Moreover, the designed electrical circuit can generate frequency source in the range of 27-30 MHz. After that, the plasma chamber was evacuated, and generated the plasma, with different types of power supply, using air as a plasma source. The results indicated that both power supplies which occurred at 4.3 W and 14.4 W generated stable plasma. Consequently, it can be concluded that the designed plasma chamber is suitable to be used to as a prototype, and can develop to apply for surface modification of biomaterials using
plasma treatment.

The purpose of this paper is to present the microstructure and mechanical behavior of 6060 aluminum alloy after intense plastic deformation. Equal Channel Angular Pressing (ECAP) was used as a method of severe plastic deformation. Before ECAP part of the samples were heat treated to remove internal stresses in the commercially available aluminium alloy. The evolution of microstructure and tensile strength were tested after 1, 3, 6 and 9 ECAP passes in annealed and non annealed states. It was found that intensely plastically deformed refined grains were present in the tested samples and exhibited increased mechanical properties. Differences were noted between samples without and after heat treatment

... Carlos Vila Pastor is an Associate Professor and the Head of the Department of Industrial Systems Engineering and Design at Jaume I University (Spain). ... One useful class of desirability functions was proposed by Derringer and Suich (1980). ...

Coating titanium alloy implants with titanium nitride (TiN) by the method of Powder Immersion Reaction Assisted Coating (PIRAC) produces a stable layer on their surface. We have examined the ability of the new TiN coating to undergo osseointegration. We implanted TiN-coated and uncoated Ti6Al4V alloy pins into the femora of six-month-old female Wistar rats. SEM after two months showed a bone collar around both TiN-coated and uncoated implants. Morphometrical analysis revealed no significant differences between the percentage of the implant-bone contact and the area and volume of the bone around TiN-coated compared with uncoated implants. Electron-probe microanalysis indicated the presence of calcium and phosphorus at the implant-bone interface. Mineralisation around the implants was also confirmed by labelling with oxytetracycline. Strong activity of alkaline phosphatase and weak activity of tartrate-resistant acid phosphatase were shown histochemically. Very few macrophages were de...

Titanium alloys are considered to be the most attractive metallic materials for biomedical applications. Ti-6Al-4V has long been favored for biomedical applications. However, for permanent implant applications the alloy has a possible toxic effect resulting from released vanadium and aluminum. For this reason, vanadium-and aluminum-free alloys have been introduced for implant applications.

The nondestructive detection of early fatigue damage states is of high importance for safety in aircraft, automobiles, railways, nuclear energy industries and chemical industries. Titanium alloys commonly used in aerospace for structures and engine components are subject to fatigue ...

Pure titanium and some of its alloys are currently considered as the most attractive metallic materials for biomedical applications due to their excellent mechanical properties, corrosion resistance, and biocompatibility. It has been demonstrated that titanium and titanium alloys are well accepted by human tissues as compared to other metals such as SUS316L stainless steel and Co-Cr-Mo type alloy. In the present study, highly porous titanium foams with porosities <or=80% are produced by using a novel powder metallurgical process, which includes the adding of the selected spacers into the starting powders. The optimal process parameters are investigated. The porous titanium foams are characterized by using optical microscopy and scanning electron microscopy. The distribution of the pore size is measured by quantitative image analyses. The mechanical properties are investigated by compressive tests. This open-cellular titanium foams, with the pore size of 200-500 microm are expecte...

Many critical engineering components are routinely subjected to cyclic multiaxial stress states, which may include non-proportional loading and multidimensional mean stresses. Initial efforts by the authors involved the identification of suitable multiaxial damage parameters for a Ti-6Al-4V titanium alloy utilizing smooth samples. As with uniaxial loading, the extension of the multiaxial data to a notched geometry poses challenges. Utilizing the

This paper reports the optimization of process parameters such as cutting speed (m/min), feed (mm/rev), depth of cut(mm) and nose radius (mm) in Dry and Wet machining using Taguchi method. Cutting fluids in machining operations help to remove the heat generated during cutting, to achieve better tool life and surface finish and to facilitate the flushing of chips. The machining without the use of any cutting fluid is becoming increasingly important due to concern regarding safety and environmental legalization. In addition it reduce 17% of manufacturing costs by not using cutting fluids. However in Dry machining operations, the friction and adhesion between chip and tool tend to be higher, which causes higher temperatures, higher wear rates and shorter tool life. This problem can overcome by using PVD coated TiAlN cutting tool. PVD-TiAlN coated carbide tools are used frequently in metal cutting process due to the higher hardness, wear resistance and chemical stability. In addition it improves tool life and machining performance. The work piece material is Ti-6Al-4V ELI which is most widely used in bio-medical applications due to its high strength to weight ratio and exceptional corrosion resistance. The cost of titanium still remain high cost but longer service life counter balance the production cost. If the work piece material is machined by Dry machining the production cost will be reduced further without affecting the quality parameters .Experiment was conducted on Dry and Wet machining with identical cutting parameters. The main output monitored was the surface roughness.

A two dimensional model was formulated for the study of the momentum and thermal behavior of atomized droplets of γ-TiAl. The velocity, temperature, flight time, cooling rate and solidification behavior of droplets were numerically investigated as a function of the axial distances from the atomization zone and the radial distances from the central line of the spray cone. The velocity,

High temperature compression deformation studies of Ti–6Al–2Zr–1Mo–1V titanium alloy in full β phase region with different strains/strain rates and then with subsequent varied cooling rates were performed to understand the microstructure evolution. Crystal orientation information and microstructure morphology of all tested samples were investigated by electron backscatter diffraction (EBSD) measurements. The crystal orientations of prior high temperature β grains were estimated by reconstructing the retained β phase at room ...