Scientists from the Institute of Laser and Welding Technologies of the St. Petersburg State Marine Technical University (SMTU, or ‘Korabelka’) developed a multilayer material using direct laser growth, which will allow parts to withstand dynamic loads longer.
The study was published in the International Journal of Advanced Manufacturing Technology.
Why it matters
The new material will be useful in the carmaking, shipbuilding, space and aviation industries.
Many critical parts, such as, for example, blades in gas turbine engines, presses, hammers, pistons, experience serious dynamic loads in certain directions. To withstand them, the metal from which the parts are made must be both strong and ductile. But in nature, such properties often contradict each other. So, SMTU researchers proposed a layered metal composite of two materials with alternate properties: pure titanium (less strong, but more ductile) and an alloy of titanium with aluminum and vanadium (more durable, but with low ductility).
Tests showed that a product made from the new material would have high strength combined with high ductility and, accordingly, withstand a higher level of impact loads. This is because it takes more energy to propagate a crack in a composite material compared to a titanium alloy. That is, cracks will propagate much more slowly, passing through layers of different materials.
“If we know the direction of the impact of the main loads on the product, then we can compensate for this by alternating layers of materials with different properties. Our approach allows us to very flexibly adjust the properties of materials and quickly create new materials for specific products,” Marina Gushchina, the institute’s head of the Materials Testing and Research Laboratory, said.
Titanium “zebra” was obtained by scientists by direct laser growth. Many approaches in additive technologies are based on this method. Metal powders are loaded into “dosers” and then sent in a controlled argon jet to the area of laser radiation. The material is grown in layers: two layers of pure titanium, then two layers of an alloy of titanium with aluminum and vanadium, and so on many times. The method allows you to combine similar and even dissimilar materials for the needs of manufacturers.
“We are engaged in science for the global implementation of our developments in industry. Customers are already interested in new materials. If three years ago one or two companies a year applied to us for the development of new materials, now 5 to 7 companies ask such questions. Our focus is on gradient materials, composite materials, high-entropy and multicomponent alloys, as well as their research and testing,” Olga Klimova-Korsmik, the institute’s head of the Materials Research Department and the Physical and Digital Materials Science laboratory, said. 
