Shell structure can increase the strength of glass by 200 times
glass has many uses. It is transparent, strong, chemical resistant and durable, but its biggest disadvantage is brittle and fragile. According to the physicist organization on January 28, recently, engineers at McGill University in Canada, inspired by the shell, developed a new type of structural glass, which is 200 times stronger than the general standard glass. Relevant papers were published in this week's nature communication magazine
the research team has made an in-depth study of some natural materials, such as shells, bones, nails, etc. Although they are all composed of brittle minerals, they have amazing toughness and resilience. The secret is that these minerals "combine" to form a larger and stronger structural unit
"combination" means that the shell contains a large number of tiny crack lines, also known as interfaces. The researchers explained that on the surface, it seems to weaken the strength and robustness of the material, but in fact, it is a sophisticated pressure deflector, which can effectively turn external pressure to differentiation. For example, the luminous inner shell of some shells, also known as mother of pearl, is 3000 times stronger than the minerals that make up it
"the introduction of weakened 'interfaces' will make materials stronger, which seems to be contrary to people's intuition, but in natural materials, this is a powerful strategy widely used." The researchers said. Using this natural strategy, they used a three-dimensional laser to carve some tiny cracks in the polymerized glass, and let the microcracks fill the interior of the glass. As a result, the strength of the glass was increased by 200 times, and it became better in bearing the impact force. When subjected to a strong impact, the relationship between stress and strain was no longer linear, and it would bend slightly rather than break immediately. Moreover, this kind of cracked glass can also be "stretched", which can stretch about 5% before being broken, and ordinary glass is only 0.1%
Francis Bassett, co-author of the paper and the Department of mechanical engineering at McGill University, said: "a container made of ordinary glass is likely to fall to pieces when it falls to the ground; but if it is made of this bionic glass, it may fall to the ground and deform rather than completely break. After falling several times, it may still work."
the shell is composed of fragile minerals, but it is hard and ductile compared with the impact energy corresponding to the quality standard impactor. At first, when imitating the shell structure, researchers tried to create a small "basic module", and then build a new material through assembly, just like building a microstructure wall. "Later, we did the opposite, starting with a large piece of material without microstructure, and then carved interfaces inside it." Baslet said
the introduction of small hardness cracks near the shaped blade in the glass will make it stronger. The new method overcomes the weakness of fragile glass in a "very economical" way. "Just a laser pulse is needed to accurately focus on the materials required in the extrusion process in advance, which not only significantly reduces the fixed position. Our 3D laser engraving technology can be easily upgraded and used on larger and thicker materials with different shapes." Baslet said. Zhonghua glass () Department