Is A Diamond Harder Than Steel?
Diamond is indeed harder than steel, with a Vickers hardness value of around 70-100 GPa, significantly surpassing the Vickers hardness value of mild steel, which is approximately 9 GPa. This significant difference in hardness makes diamond one of the hardest substances known, far exceeding the hardness of steel and most other materials.
Understanding the Hardness of Diamond and Steel
The hardness of a material is determined by its ability to resist scratching, abrasion, and deformation. Diamond, composed of pure carbon arranged in a cubic crystal structure, achieves its exceptional hardness due to the strong covalent bonds between its carbon atoms. This unique arrangement and bonding give diamond its remarkable mechanical properties, including its hardness.
Comparing Diamond and Steel
Steel, an alloy primarily made of iron and carbon, has a hardness that can vary depending on its composition and processing methods. While steel is incredibly strong and versatile, its hardness is generally much lower than that of diamond. The hardness of steel can range from approximately 5 to 8 on the Mohs hardness scale, whereas diamond ranks at the top with a Mohs hardness of 10.
FAQs About Diamond and Steel Hardness
1. What is the Vickers hardness of diamond and steel?
The Vickers hardness of diamond is around 70-100 GPa, and that of mild steel is approximately 9 GPa.
2. Can steel break diamond?
No, steel cannot break diamond due to diamond’s superior hardness and toughness. However, a direct hit with an ordinary hammer can break a diamond due to the concentration of force.
3. Is diamond the hardest metal?
Diamond is the hardest substance known, ranking at the top of the Mohs scale of hardness. However, it is not a metal; it is a form of pure carbon.
4. How does the density of diamond compare to steel?
Steel is far denser than diamond, with each molecule of steel weighing more than a carbon atom.
5. Why can’t diamond cut steel at high temperatures?
At temperatures above 700°C, the carbon atoms in diamond react with iron in steel to form iron carbide, which can damage the diamond.
6. Can a bullet break a diamond?
Yes, a bullet can break a diamond. Diamonds are not strong enough to stop a bullet.
7. What can break a diamond?
Diamonds can break or chip from powerful accidental blows or due to internal strain.
8. What can cut a diamond?
Diamonds are cut with specialized tools using diamond-tipped phosphor bronze or diamond-dusted steel blades that exploit the diamond’s structural weaknesses.
9. Can diamonds crack in fire?
Yes, diamonds can be damaged by flame and may appear cloudy and white due to combustion on the surface.
10. Can fire destroy a diamond?
Diamonds will burn at about 1562°F (850°C), and while they do not go up in smoke, they can combust on the surface, leading to a cloudy appearance.
11. Can a knife scratch a diamond?
No, a knife cannot scratch a diamond unless the knife is also made of diamond.
12. Can water cut diamond?
A powerful enough water jet can cut a diamond, but this is highly exceptional and not commonly possible.
13. What is the hardest thing on Earth?
Diamond is considered the hardest substance found on Earth, with a Mohs hardness of 10.
14. What’s the strongest thing on Earth?
Among the strongest materials known are graphene, buckypaper, metallic glass, dyneema, lonsdaleite, wurtzite boron nitride, diamond, and nanospheres/nano-kevlar.
15. Can diamonds ever be destroyed?
Yes, diamonds can be damaged and destroyed. While they are the hardest mineral, they are not immune to breakage and destruction under certain conditions.