Development and application of titanium alloy casting technology in China
The development and research of titanium cast alloy and its casting technology, especially its application in aeronautical industry in China are presented. The technology of molding, melting and casting of titanium alloy, casting quality control are introduced. The existing problems and development trend in titanium alloy casting technology are also discussed.
Titanium in biomedical applications—properties and fabrication: a review
Ti and Ti-based alloys have unique properties such as high strength, low density and excellent corrosion resistance. These properties are essential for the manufacture of lightweight and high strength components for biomedical applications. In this paper, Ti properties such as metallurgy, mechanical properties, surface modification, corrosion resistance, biocompatibility and osseointegration in biomedical applications have been discussed. This paper also analyses the advantages and disadvantages of various Ti manufacturing processes for biomedical applications such as casting, powder metallurgy, cold and hot working, machining, laser engineering net shaping (LEN), superplastic forming, forging and ring rolling. The contributions of this research are twofold, firstly scrutinizing the behaviour of Ti and Ti-based alloys in-vivo and in-vitro experiments in biomedical applications to determine the factors leading to failure, and secondly strategies to achieve desired properties essential to improving the quality of patient outcomes after receiving surgical implants. Future research will be directed toward manufacturing of Ti for medical applications by improving the production process, for example using optimal design approaches in additive manufacturing and investigating alloys containing other materials in order to obtain better medical and mechanical characteristics.
Effects of thermal exposure on the microstructure and properties of a γ-TiAl based alloy containing 44Al–4Nb–4Zr–0.2Si–0.3B
Abstract The microstructural stability after long-term aging at 700°C of a TiAl-based alloy containing 44Al–4Nb–4Zr–0.2Si–0.3B (in at%) has been studied. The microstructural observations are consistent with those established previously, i.e. even as low as 700°C the microstructure is unstable in that after prolonged aging, decomposition of the α 2 lamellae and increased volume fraction of gamma phase have been observed. Despite this, it has been shown that, with a combination of slow cooling from the annealing temperature and a ‘stabilisation’ treatment at an intermediate temperature, the mechanical properties of this alloy can be retained. This increase in thermal stability has been attributed to the large α 2 lamellae which result from slow cooling and are less susceptible to complete dissolution during aging, and also to the formation of gamma grains which are embedded in and constrained by the ω phase between the lamellar colonies. ©