Scientists create a particularly durable pseudoplastic material

Composite materials, which are employed in modern technology, have great rigidity, strength, and fragility. Scientists have learned how to produce unique composites that have unusual pseudoplasticity. The work employs an original theory, proposed by Prof Sapozhnikov from South Ural State University (Chelyabinsk, Russia). An article on the new pseudoplastic CFRP (carbon fiber reinforced polymer) has been published in Composites Part B: Engineering, the journal with the highest JCR-rank (2019) in the composite materials field.

Carbon fiber composite materials have been used for decades. Their use is remarkably widespread in aviation and astronautics. These materials are light-weight, but at the same time possess extraordinary strength. However, composite materials are relatively fragile. If a structure made of such a material is affected by a force slightly greater than the calculated value, then the object is destroyed instantly. Therefore, scientists who study composites are proposing alternative options for pseudoplastic non-fragile materials. To create them, different composites are combined: carbon fiber and fiberglass, carbon fiber and organic plastic, etc.

Professor Sergei Sapozhnikov, together with professors Yentl Svolfs and Stepan Lomov from the Catholic University of Leuven (KU Leuven, Belgium), proposed to produce an experimental material based on two brittle carbon plastics—ultra-high-strength and ultra-high-modulus.

The joint work was supported with a grant from the Russian Science Foundation (RSF), by the administration of the Catholic University of Leuven and the Japanese company TORAY, a supplier of materials and sponsor of the Chair for Composite Materials in the Catholic University of Leuven.

It was formerly considered that only thin-layer hybrid composites possess the pseudoplastic properties. The team of scientists showed that the effect of pseudoplasticity can be obtained on composites with standard layer thicknesses. It is only important to have enough fracture toughness at the interface of two layers. The team described this property in their first article.

"I have used two hybrid composites to create one material with a unique property called pseudoplasticity. Such materials do not fail suddenly. First, they are initially elastically deformed, then accumulate microdamage, and then destroyed. Pseudoplasticity is necessary to make materials more durable. These hybrid composites have higher strength, but much lower density than steel. With the help of my software program, we created such materials and experimentally proved that these composites can be used," Sergei Sapozhnikov says.

The collaboration with the University of Leuven is not accomplished: the team intends to test how the new material will resist repeated loads. Professor Valter Carvelli of Politecnico di Milano, Italy, is also collaborating on this topic. The research will be further developed by the study of polymers wear resistance.

Sergei Sapozhnikov also noticed that the data obtained by the international team can at present be used in practice around the world.

More information:
www.sciencedirect.com/science/ … ii/S1359836820332637

Provided by South Ural State University