The Mechanical Properties of Diamond

Perhaps diamond is the hardest material on the earth (it is said that there are still some harder materials). It has high thermal conductivity, high insulation and high chemical stability. It can be used to process non-ferrous metals such as aluminum and copper both efficiently and precisely, and is especially suitable to process hard and brittle non-metallic materials.

1) High hardness, high wear resistance: Diamond has the highest hardness value. Its abrasive hardness is 150 times of corundum, 1000 times of quartz and 6 times of carbide alloy.

2) Low friction coefficient: The friction coefficient between diamond and metal in the air is 0.1. Therefore, diamond has a very high frictional resistance. Its friction resistance is 90 times of corundum, 100 times of carbide alloy and 9000 times of steel.

3) High strength: Diamond’s crystal structure, its Impurity’s composition and content determine the strength of a diamond. Natural diamond’s compressive strength is about 8000 kg/cm², which is about 3.5 times of corundum, 1.5 times of carbide alloy and 9 times of steel.

4) Though diamond has high hardness and high strength, it also has brittleness. When a diamond receives a certain degree of impact force, it may generate cracks or even be broken into regular-shape small pieces. This is the biggest weakness of diamond.

5) High thermal conductivity, bad thermal stability: The change of temperature has a fairly big influence on the strength of diamond. With the rise of temperature, diamond’s strength declines.