Authors: Mithun Kumar, P. Sudhakar Rao
Abstract: Because of their extraordinary qualities, titanium alloys are very sought-after materials that can be applied to a wide range of sectors. Excellent mechanical and chemical qualities, including a high strength-to-weight ratio and resistance to corrosion, are present in it. The special properties of these alloys make machining them extremely difficult. As frequent tool wear occurs throughout the machining process, Computer Numerical Control (CNC) milling has become a potential method for machining titanium alloys due to its precision and versatility. This review article provides a comprehensive overview of the development of titanium alloy CNC milling, with an emphasis on the effects of cutting tool geometries and materials on machining efficiency. The process examines several aspects of cutting circumstances, including depth of cut, speed, feed rate, and lubrication techniques, and optimizes machining parameters and procedures to achieve the best results. Surface integrity and quality, surface roughness, residual stresses, and microstructural changes brought about by CNC milling are the main points of evaluation.
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Authors: Sengo Kobayashi, Ryohei Fukushima, Siqi Wu, Satoshi Okano
Abstract: The addition of oxygen or nitrogen in titanium alloys increases the hardness by the solid solution strengthening. Spinodal decomposition in titanium alloys is also the way to increase the hardness. This study aimed to reveal the effect of oxygen or nitrogen addition on spinodal decomposition in Ti-10at%V. Ti-10at%V-(0, 1, 3)at%O or N alloys were prepared by arc-melting. They were solution-treated at 1200 or 1300 °C for 0.6 ks and then quenched in iced brine. The solution treated specimens were aged at 375 °C. The increase of hardness was decreased by the oxygen or nitrogen addition in the alloys. The addition of nitrogen more suppressed the age-hardening than the case of oxygen addition. The modulated structure caused by spinodal decomposition in the laths was observed in all the aged specimens. The wavelength of spinodal decomposition of the aged specimens increased with the addition of oxygen or nitrogen, leading to a decrease in age-hardening by spinodal decomposition.
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Authors: Marek Vrabeľ, Ildikó Maňková, Peter Ižol, Mária Franková, Miroslav Paľo
Abstract: Titanium alloy Ti6Al4V represents one of the most frequently used alloys in medical as well as in aerospace industry and is considered as a difficult to cut material. In this paper, cutting experiments within throughput drilling were carried out under the varying cutting speed, feed and tool geometry (cutting edge radius and clearance angle). The effects of cutting speed feed and tool geometry on thrust force in drilling Ti6Al4V alloy were investigated applying design of experiment (DoE) according to Taguchi plan L16. The effect of above mentioned parameters was investigated through analysis of the S/N ratios (smaller is better) and ANOVA analysis. All analyses were performed using statistical software Minitab and Matlab. In the case of thrust force, the feed is the main influencing factor, followed by cutting speed, cutting edge radius and clearance angle.
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Authors: Aleš Jíra, František Denk
Abstract: The submitted experimental analysis identifies, defines and compares the micromechanical properties of peripheral and supporting layers of intraosseous parts of dental implants through a nanoindentation method. The aim of the micromechanical tests is determination of elastic modulus and hardness. Investigated implants are characterized by the cylindrical shanks with surface plasma modification by hydroxyapatit. From the evaluated results it is evident that elastic modulus of peripheral layers of the compared samples ranges from 17 GPa to 157 GPa. The submitted work also includes a detailed microscopic analysis of surface morphology and chemical composition.
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Authors: Rohit Kumar Gupta, V. Anil Kumar, Abhay R. Chauthai, P. Ramkumar
Abstract: Titanium alloy Ti6Al4V is used for manufacturing pressure vessels of launch vehicle in view of its excellent corrosion resistance and fabrication characteristics. This material also offers advantage of good strength to weight ratio necessary for space application. This paper describes the experience gained in the technology development of hemispherical forgings of titanium alloy Ti6Al4V. To achieve α-β microstructure and mechanical properties in the final product, hot working of the alloy from the stage of forging of cast ingots to finish working was carried out in the (α-β) region. The manufacturing parameters are established through state-of-the-art technology and capabilities. Process technology for processing of the hemispherical dome has been established and the same has been presented here.
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Authors: Li Ming Zou, Yi Xiang Cai
Abstract: (Ti69.7Nb23.7Zr4.9Ta1.7)100-xFex (x=0, 2, 6, and 10) nanocrystalline, nanocomposite and amorphous powders were synthesized by mechanical alloying from blended element powder. The structural transition for the milled powders was confirmed by X-ray diffraction (XRD). Results shows with the increasing Fe content in alloy system, the glass forming ability become larger. Only for x=10, it can obtain nearly completely amorphous structure with wide super cooled liquid region (△Tx =122 K). For x=2 and 6, residual nanocrystals of the β-Ti structure dispersed in the amorphous matrix. For x=0, the milled powder has full nanocrystalline structure. These as-milled powders offer the potential to fabricating the bulk glass material or nanocrystal/glass matrix composites by powder metallurgy for biomedical use.
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