2017 has already proven to be an incredible year, with regard to innovations and engineering advances. One of the most interesting discoveries comes from the Max Planck Institute for Iron Research, with the multifunctional titanium alloy being the focal point of attention. According to the scientists belonging to the research department, it seems that the titanium alloy presents a unique crystal structure. The peculiarities of this structure might make it suitable for industrial applications, especially in the aerospace industry.
The multifunctional innovative titanium alloy, thanks to its crystal-based structure and bending abilities, can be easily presented as a gum metal. These metals have been analyzed for a number of years now but it was only recently that scientists managed to understand how they could be used for various industrial applications. The researchers at the German institute demonstrated that the crystal structure of the titanium alloy changes when subjected to mechanical stress (new phase transformation).
Apart from titanium, this alloy also contains zirconium, tantalum and niobium. The structure analysis of the titanium alloy was made with the help of the X-ray technology, scientists paying careful attention to its inner structure. Interestingly enough, it was revealed that, under mechanical stress (deformation), the titanium alloy does not harden or become brittle (characteristic for most metals). Instead, it exhibits incredible bending properties; the two reasons for which these changes occur are the high malleability and the reduced elastic rigidity.
Industrial applications could benefit tremendously from the usage of gum metals, such as the titanium alloy. One of the best examples that could be offered is the aerospace industry, where metals that bend easily could also absorb shocks with increased efficiency (crash absorber). Airplane turbines are often damaged by weather elements, such as hail or as a result of bird strike accidents. The biggest risk is damage to vital airplane parts, such as the fuselage.
In the future, researchers hope that the casing that protects the airplane turbines could be made from gum metals. The titanium alloy could then absorb shocks and protect the airplane from the flying debris. More importantly, the turbine would no longer suffer from extensive damage (deformation instead of large-scale destruction).
As it was already mentioned above, the inner structure of the titanium alloy was analyzed with the help of X-ray technology. German scientists also used transmission electron microscopy and atom probe tomography, in order to get a better look at the nanostructure of the gum metal and ascertain its peculiarities.
There are two different phases in which the titanium alloy occurs, as previous research had demonstrated. The first is represented by the alpha phase, which occurs at room temperature; as for the second, this is known as the beta phase, being characterized by high temperatures. All metals change their properties, according to the phase and the consequent temperatures. Gum metals, such as the titanium alloy, have been found to primarily consist of the beta phase, remaining in a stable state at room temperature.
The crystal structure of the titanium alloy was analyzed, using X-ray technology, especially during the transition phase. Researchers used a sample of the titanium alloy, observing how the X-rays are reflected by its crystal structure. They have then analyzed the reflection pattern, being able to conclude the position of the atoms that make up the nanostructure of the titanium alloy. It was discovered that, during the transition phase, they adopt a particular structure; this structure is responsible for the above-mentioned properties of the titanium alloy, making it suitable for a wide-range of industrial applications.
When the titanium alloy goes from the beta to the alpha phase, it re-arranges completely, thus forming a new structure. Scientists have called this the omega phase or the transition/transformation phase. They have also observed that the rapid cooling down of the beta phase can lead to the better positioning of the atoms in the alpha phase. This re-arrangement is considered to be more favorable, from an energetic point of view. Moreover, it has been discovered that the re-arrangement of the crystal structure actually leads to mechanical stress. A certain value has to be exceeded, in order for the atoms to position themselves in the final arrangement (all of these changes occurring, of course, during the so-called omega phase).
If the generated mechanical stress does not reach a certain level, the transition from one phase to the other will not be facilitated or will occur with delay. The new structure exists only during the omega phase, being actually kept in a stable position by the two other phases.
When new layers are created, this will lead to a reduction in the generated mechanical stress. In turn, this will lead to the formation of a new alpha phase layer. The gum metal will thus present a layered nanostructure, each of the layers presenting a completely different structure. Interestingly enough, the external application of static forces leads to the same changes (which can be reversed 100%).
The newly-discovered structure of the titanium alloy paves the way for innovative industrial applications, such as the ones concerning the aerospace industry and airplane turbines in particular. In the future, researchers hope that the titanium alloy could be used in other fields as well, including the automotive manufacture industry and medical equipment. It could change the quality and increase the versatility of different goods, contributing to the development of unique products.
Further research will be necessary in the near future, in order to determine the reasons for which the innovative titanium alloy changes its structure, during the transition phase (to an extensive degree). Advanced technologies will most likely replace the current ones, allowing scientists to get better insight into the nanostructure of the titanium alloy and its re-arrangement during different phases. At the moment, scientists are concentrating on the in-depth analysis of the titanium alloy structure. They are resorting to heat treatment, in order to find out more information on this particular gum metal and discover ways in which it could be used, in order to create innovative structural materials.