Top 10 Hardest Materials
Diamond is widely believed to be the hardest known material to man, but is it really the case? What are the other hard materials apart from diamond? Well, today our list will answer these questions for you.
No 10. Alumina
Alumina is a common name for Aluminum Oxide, which is an amphoteric oxide and is more even more commonly known as Corundum in its crystalline form. Alumina in its alpha phase is the strongest and stiffest of the oxide ceramics; alpha phase is the most stable hexagonal phase achieved at high temperatures. Alumina is used in gas laser tubes, electronic substrates, ballistic armor and grinding media. Varieties of alumina exist and the more known of them are Ruby and Sapphire which are categorized based on impurities as well as color.
No 9. Boron carbide
This is an extremely hard ceramic material most notably used in tank armor and bulletproof vests. It finds its use in padlocks, neutron absorber in nuclear reactors, high energy fuel for solid fuel Ramjets and anti-ballistic armor plating.
No 8. Zirconium carbide
Appearing as a gray metallic powder Zirconium carbide is an extremely hard refractory ceramic material, commercially used in tool bits for cutting tools. Zirconium Carbide along with Zirconium Oxide are known as modern ceramics and is extremely hard, wear resistant, and chemically inert.
No 7. Titanium diboride
Titanium Diboride is an extremely hard material with very good high temperature corrosion resistance. It is a ceramic and therefore is a material of high interest due to being electrically conductive. Titanium diboride is more than three times strong the strongest steel available.
No 6. Titanium carbide
Titanium carbide is a hard ceramic material with excellent tribological wear properties. It has a high Mohs rating in the range of 9-9.5 and is mainly used in preparation of cermets, which are frequently used to machine steel materials at high cutting speed.
No 5. Rhenium diboride
First synthesized in 1962, Rhenium diboride, synthetic superhard material, compared to the others materials on the list is a cheaper material to make as its production does not involve high pressures. Above, the first picture shows Rhenium diboride in powder and pellet form and the second shows the element Rhenium.
No 4. Borazon
This is a variation of Boron nitride (more correctly called cubic boron nitride) and is obtained by heating equal quantities of boron and nitrogen at temperatures greater exceeding 1800 degree Celsius. Borazon finds its use in grinding wheels among other materials. Brozan was also used as a cheaper alternative to diamond.
No 3. Diamond
Diamonds was the hardest naturally occurring material for some time and it grows in about a time of 1 billion to 3.3 billion years under high pressure. Diamonds are mostly used for adornment and by drillers to drill more efficiently.
No 2. Lonsdaleite
Lonsdaleite is also knows as hexagonal diamond and is formed when meteorites containing graphite strike the Earth, so it is pretty rare. It is translucent, brownish-yellow in color and purest form of it is more than 50 percent harder than diamond.
No 1. Wurtzite boron nitride
Wurtzite boron nitride has a structure very similar to that of a diamond but with a few improvements making it very much stronger than it. Wurtzite boron nitride is also extremely rare and is produced during volcanic eruptions.