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Materials for 3D Printing in Medicine
Published in Harish Kumar Banga, Rajesh Kumar, Parveen Kalra, Rajendra M. Belokar, Additive Manufacturing with Medical Applications, 2023
Kamal Kishore, Roopak Varshney, Param Singh, Manoj Kumar Sinha
In old age, health problems like bone fracture and tissue losses are more common. These problems require metals for fixation, replacement and reconstruction of tissue and bone. These metals provide support to the patient for immediate mobilisation (Niinomi, 2007). Metals and their alloys have better mechanical characteristics such as high strength, high elasticity, better anti-wear and corrosion resistance. Nowadays, around 75 per cent of medically used implants are made of metals like stainless steel, titanium alloys (Banerjee & Williams, 2013), cobalt-chromium alloys (Hsu et al., 2005), niobium, nitinol and tantalum (Black, 1994). But in recent years, biodegradable metals such as magnesium (N. Li & Zheng, 2013), zinc (Xiang et al., 2014), iron (Vorndran et al., 2011) and calcium are more in use for the manufacturing of implants. Table 5.2 presents a brief of different types of metals used in the biomedical field. For medical applications, AM-based metal and their alloys are classified into three groups as mentioned below:Conventional metals and their alloysBiodegradable metalsShape-memory alloys
Properties and applications of engineering materials
Published in Alan Darbyshire, Charles Gibson, Mechanical Engineering, 2023
Alan Darbyshire, Charles Gibson
Alloys are formed when different metals, and sometimes also metals and non-metallic substances, are mixed together in the molten state. After cooling, the resulting solid solution may be an interstitial alloy (Figure 5.8), a substitutional alloy or an intermetallic compound. In an interstitial alloy, the atoms of one of the constituents are relatively small compared to those of the other. As the molten mixture solidifies and the crystals start to form, the smaller atoms are able to occupy the spaces between the larger atoms.
Solids: comparison with experiment
Published in Michael de Podesta, Understanding the Properties of Matter, 2020
Alloys are usually made by melting metallic elements together and mixing them while they are molten. The electrical resistivity of three alloys is compared with the electrical resistivity of their constituent elements in Table 7.13. There is one surprising feature of this table. In all cases the resistivity of the alloy is considerably greater than the resistivity of either component element. This is particularly striking for the Pt(10% lr) and Pt(10% Rh) alloys. For example, replacing 1 in 10 platinum atoms with an iridium atom causes the resistivity to more than double. This is despite the fact that iridium has a lower resistivity than platinum!
Corrosion behaviour of oxide film formed on carbon steel in high temperature alkaline water in the presence of zinc and magnesium ions
Published in Corrosion Engineering, Science and Technology, 2023
Sumathi Suresh, Santanu Bera, Chandramohan Palogi, Sundaravel B, Jegadeesan P, Krishna Mohan T.V
Iron-based alloys are widely used as structural materials in power generation industries, which contain other elements as minor or major alloying components. The alloying elements impart strength, hardness and corrosion resistance to these alloys. Carbon steel (CS), an iron-based alloy, constitutes a major proportion of piping in the primary heat transport (PHT) system of Indian pressurised heavy water reactors (PHWRs) operating below 320°C. Long-term operation of these reactors generates corrosion products in circulating high temperature and high pressure water. These corrosion products get neutron activated in the reactor core, become radioactive and subsequently get incorporated into the magnetite (Fe3O4) film on CS causing man-rem problems during service maintenance. The buildup of radiation fields around piping components is due to the deposition of cobalt isotopes (60Co), which is a matter of high concern in nuclear power industry [1].
Microstructural Characterization and Mechanical Properties of Metastable Beta and α+β Titanium Alloy Electron Beam Weldments
Published in Fusion Science and Technology, 2023
Vamsi Krishna K, Gopi Krishna C, Nagendra Polamarasetty, Mahesh Kumar Talari, Vijay N. Nadakuduru, Kishore Babu Nagumothu
Titanium alloys are categorized into α, α+β, and β alloys based on phase stability at room temperature.[1,2] Ti-6Al-4V (Ti-64), an α+β Ti alloy, is a workhorse grade of aerospace alloys widely used in aerospace, automobile, medical, and marine industries due to their good corrosion resistance, good creep resistance, high fatigue life, and excellent toughness. On the other hand, β-Ti alloys possess superior tensile strength, good cold formability, and easy heat treatability. These alloys are used in many industry sectors such as automotive, aerospace, biomedical, construction, and sporting. In particular, Ti-15V-3Cr-3Al-3Sn (Ti-1533), a metastable β-Ti alloy with high alloy content, is particularly well suited for applications in the chemical, petroleum, and aerospace industries due to its remarkable combination of cold workability, high strength, excellent hardenability, and high fracture toughness.[3,4] The strength of this alloy is shown to increase with aging due to the precipitation of a fine, uniformly dispersed α phase in the β matrix.[5]
Evaluating the corrosion behaviour of AA6061-T6 alloy and its friction stir welded joints
Published in Canadian Metallurgical Quarterly, 2023
Navdeep Minhas, Lenka Sudheer, Varun Sharma, Shailendra Singh Bhadauria
Aluminium is a light structural metal, which possesses excellent mechanical and corrosion properties when alloyed with other elements such as Si, Mg, etc. Such alloys are extensively being used in diverse business areas, which includes spacecraft components, railways, shipbuilding, aerospace, automobiles, family appliances, electronics, etc., owing to their good structural efficiency, much less weight, low density, high resistance to corrosion, excellent workability and good electrical conductivity. Among the different variants of aluminium alloys, the AA6XXX series alloys show excellent corrosion resistance properties [1]. These alloys own good age hardenability characteristics and are commonly heat-dealt with T4 (natural aging solution therapy) and T6 (aging to the peak) age-hardening conditions [2]. Within the AA6XXX series alloys, the AA6061-T6 grade is the most commonly used age-hardened alloy, which possesses good weldability, top extrudability, and exquisite corrosion resistance. Owing to the good mechanical and corrosion properties, it is used in the fuel plate structure in the research nuclear reactors. Further, the parent AA6061-T6 alloy structure is exposed and the purity of the coolant is not well controlled and subjected to the contamination, which will further allow alloy to corrode [3].