What s stronger than a diamond in real life?

Diamond is rated a 10 on the Mohs hardness scale, indicating that it is the hardest natural material when scratched. However, lonsdaleite, a substance found in meteorites, is predicted to be even harder than diamond. Ask any science buff: “What is the hardest material?” – and he will undoubtedly answer: “Diamond.” For decades, people have used diamond’s flawless hardness for intensive cutting. Additionally, given its ability to interact beautifully with light, diamonds are a highly desirable piece of jewelry for women. But is diamond really the hardest material on Earth? Well, almost. scientists have discovered a potential contender that is believed to be even harder than diamond.

The hardest naturally occurring substance on our planet

When it comes to natural solids, diamond is the clear winner. Its compact structure makes it very hard to beat. Now the question arises. how do we measure hardness?

Hardness measurement

In materials science, assessing the hardness of a material is very important. However, determining hardness is not so easy. Thus, hardness can be measured in different ways depending on the context and applicability.

Mohs hardness scale

One of the most commonly used hardness scales is the Mohs hardness scale, developed by German mineralogist Friedrich Mohs in the nineteenth century. On this scale, hardness is a measure of the resistance one material exhibits when scratched by another material. The Mohs hardness scale ranges from 0 to 10, with 10 being the hardest (least scratch-prone) and 0 being the least hard. Diamond scores a 10 on this scale, which clearly indicates that it is the hardest natural material when subjected to scratching. To understand how good a diamond is, consider steel, which is known for its hardness and is only rated 4,5 on this scale! So, measuring hardness by the resistance of a substance to scratches was not approved by everyone. Thus, scientists began to look for an alternative method for measuring hardness. Another hardness determination technique was developed in which an indenter was used to evaluate hardness.

Vickers hardness test

One of the most famous tests for determining hardness using an indenter is the Vickers hardness test. In this hardness testing method, a pyramid-shaped indenter is pressed against the material whose hardness is to be assessed. A certain force is applied to a given material for a certain time. After this indentation, the degree of indentation in the material is measured. This is done by measuring the surface area of ​​the indentation made by the indenter into the material. Here again, diamond was found to be the hardest natural material on Earth.

What makes a diamond so hard?

At this point you may be asking yourself, what makes a diamond so hard? The answer lies in the molecular structure of this shiny element. Diamond is an allotrope of carbon, consisting of five carbon atoms that share electrons with each other in a tetrahedral lattice structure. The covalent bond between these carbon atoms is extremely strong and very difficult to break at room temperature. Because of this strong covalent bond, diamonds have no free electrons, making them a poor conductor of electricity but an excellent conductor of heat. In fact, diamond is about five times better at thermal conductivity than copper. Due to their fantastic thermal conductivity, diamonds are often found in electrical components such as radiators.

Diamonds are not invincible.

After reading this, you may feel that diamonds are invincible, but in reality they are not. Diamond becomes vulnerable at very high temperatures. When you heat a diamond above 800°C, its chemical and physical properties no longer remain unchanged. Violation of the characteristic strength of diamond. They begin to react chemically with the iron, making diamond undesirable for cutting steel. The characteristic hardness of the diamond is disrupted. They begin to react chemically with the iron, making diamond undesirable for cutting steel. Therefore, scientists and researchers have long been looking for a superhard material with better chemical stability. In 2009, researchers working in collaboration from Shanghai Jiao Tong University and the University of Nevada said they had found two materials that could beat diamond at its own game! Two proposed potential contenders for the hardest substance were wurtzite boron nitride (w-BN) and Lonsdaleite.

Wurtzite boron nitride (w-BN)

Wurtzite boron nitride (w-BN) has a structure similar to that of diamond, but it is composed of boron and nitrogen atoms as well as carbon. Wurtzite boron nitride is extremely rare and can only be found after a certain type of volcanic eruption. A 2009 simulation by researchers of w-BN’s hexagonal structure showed that it was 18% harder than steel. In addition, w-BN is chemically more stable than diamond at high temperatures.

Lonsdaleite

Lonsdaleite is composed of only carbon atoms, like diamond, although with a different structure. And guess what. lonsdaleite is even stronger than w-BN! Interestingly, lonsdaleite is a cosmic substance that is created when a graphite-rich meteorite hits the Earth. Indentation simulations showed that lonsdaleite is 58% harder than diamond, making lonsdaleite the hardest substance on Earth.

Wait, there’s a catch.

However, there is a catch to these claims that w-BN and lonsdaleite are stronger than diamond. These statements are based on a simulation program run on a computer and not on physical verification. Because these elements are extremely difficult to find, they have not yet been physically tested to determine their hardness. However, their modeling suggests that these harder-than-diamond materials have good thermal and chemical stability; if we can synthetically produce them in large enough quantities, they could prove game-changing. They could be used as powerful cutters by placing them on top of other cutting tools. Additionally, their stability at higher temperatures would make them useful on space missions to Venus or Mercury, which have blisteringly high temperatures. Well, diamond may theoretically lose its crown as the hardest material, but it will always remain the king of gemstones. Moreover, the claim that lonsdaleite is the hardest substance has not yet been physically confirmed. The well-known postulate that diamond is the hardest material is losing its significance: Chinese chemists now attribute this property to a rare mineral that is 58% harder than diamond. Scientists from Shanghai Jiao Tong University simulated the extreme impact of pressure from a probing indenter on crystals of two rare substances that claim to be the hardest materials Boron nitride (BN) with crystal lattice type wurtzite (w-BN) resembles the structure of diamond, and if this hexagonal lattice is built of carbon atoms, then it is called lonsdaleite. Lonsdaleite is a well-known allotropic modification of carbon – “black diamond”. In nature, boron nitride wurtzite and lonsdaleite are extremely rare; and although these substances can be obtained in laboratory conditions, no one has yet tested their extreme strength. The figure shows the structures of A) diamond B) wurtzite (w-BN) C) lonsdaleite Assumptions based on the results of modeling carried out by Chinese scientists allow us to say that wurtzite boron nitride and lonsdaleite are stronger than diamond by 18% and 58%, respectively. If this is confirmed in the experiment, then two new solid substances will appear in the world. Of course, conducting such an experiment is not an easy task. To test, you must have sufficient quantities of these very rare minerals. Lonsdaleite occurs in a rock formed by graphite-bearing comets that fell to Earth. Wurtzite boron nitride is formed during volcanic processes at very high pressures and temperatures. Hardness in lability Of the two minerals described, boron nitride wurtzite may be more useful in a practical sense, since it is more inert to oxygen at elevated temperatures than diamond. The material can be used to make excellent surface finishing or drilling tips that can operate at high temperatures, as well as corrosion-resistant films, for example for aircraft skins. An interesting and, in a sense, paradoxical property of wurtzite boron nitride determines its phenomenal hardness: this is the mobility of the bonds between its atoms. When the material is subjected to load, some of the bonds are reoriented at an angle of 90° and thus the resulting stress is partially smoothed out. The structure of diamond is also capable of undergoing similar changes, but, unlike wurtzite boron nitride, which becomes noticeably (about 80%) stronger, diamond does not have this property. The problem of single crystals Research in this area is also being conducted at the University of Heidelberg, Germany. Natalya Dubrovinskaya, the work manager, explains that “it is very important to find out the details of the mechanism that improves the technological characteristics of the material and, especially, such a complex characteristic as hardness.” Having understood the principle of changing the hardness of materials, we can further set the task of obtaining materials with specified properties. However, to clearly construct and test theoretical concepts, it is necessary to have single-crystal samples of the material; To date, methods for isolating or artificially obtaining such crystals from any substance have not yet been developed. Source – http://www.nanonewsnet.ru/news/2009/naiden-mineral-prevoskhodyashchii-po-tverdosti-almaz
Maria Kostyukova, published 20.02.2009/XNUMX/XNUMX Article “China has created a material stronger than diamond,” published on our website 15.02.2009/XNUMX/XNUMX Until now, diamond was considered the strongest and hardest chemical compound on the planet. Thanks to its unique crystal lattice that can withstand enormous pressure, diamonds are widely used in cutting tools, heavy industry, and cutting durable components.
However, scientists are always busy searching for more advanced developments, and this time Chinese physicists from Tong Zhao University in Shanghai have developed two composite materials that are harder than diamonds. The first was called “crystallized boron nitride.” This material has already been obtained, although in small quantities so far. And the second one was called “lonsdalite”, It, like diamond, has a crystalline carbon atomic lattice, which, however, has a hexagonal shape. Lonsdalite is 58% stronger than diamond, although experts still only have this element in their calculations and have not reached the point of production. Shanghai experts say their research represents the first experiments aimed at creating practical superhard materials suitable for industrial use. Both elements are the products of a series of chemical reactions, as well as the great pressure under which they were created. According to Chen Changfeng, the head of the research, in fact, both created elements are derived materials that changed their atomic structures under the influence of high pressure.