Hardening is one of the oldest metallurgical processes known to mankind, originally, in the form of heating the sword and then dipping it in water to achieve hardness. In conventional hardening, the workpiece to be hardened is first heated to a very high temperature. For heating, there are many ways. For example ,either a furnace is used, or a customised coil is prepared according to the geometry of the component. Then this coil is heated using alternating current, and this is used to raise the temperature of the component. After that the component is quenched in oil or water externally.

Benefits Of Hardening

• Increased hardness
• Increased wear resistance
• Increased fatigue life
• Increased strength

However, conventional hardening has some shortcomings. Firstly, it is time consuming because customised coils have to be prepared according to each component or the turnaround time required in conventional furnace based hardening is more . Also It requires quenching and due to this there is distortion in the parts so it requires post processing.

Laser Hardening Process in Brief :
Laser Hardening is a case hardening process , a heat treatment process in which high powered diode laser beams are scanned over work-piece material to heat localized areas of the surface. It is used to increase the strength and durability of material. As the laser beam is scanned over the surface, it instantaneously heats the surface. The amount of heat transferred to the material depends on the absorptivity of the material. The surface is instantaneously heated above austenitizing temperature. This heating takes place locally, and bulk of material works as heat sink and cooling takes place rapidly through conduction, resulting in self quenching effect. This results in formation of very fine martensite structure and leads to maximum achievable hardening of the material.