Transformation Hardening
The main features of the laser as a heat source for transformation hardening are:
(A) Clean energy source.
(B) Energy is localised: no heat spillage.
(C) Only surface layer heated: core properties are unaltered.
(D) Low heat input: therefore low thermal distortion.
(E) Fast process: therefore no oxidation. The process can be a final operation.
(F) Self quenching: no water or oil sprays.
(G) Easily automated: the laser fits naturally into a numerically controlled system with time sharing between work stations.