In metallurgy, hardening describes techniques to increase the hardness of a material. There are four main types of hardening:
There are a number of ways in a pure metal or even an alloy can be made stronger so that they may be used more effectively in engineering applications, Hardening is one. During hardening, the metal is compressed by hammering or some sort of forced work done on it. Dislocations are generated in the crystalline structure of the metal and because they move they form tangles, It should be noted that different materials harden at different rates and to different extents.