Non-destructive magnetic testing of laser hardening parameters

Because of the increasing commercial use of high power lasers for surface annealing treatments, non-destructive testing methods to improve the production quality and reliability are necessary. Therefore the general aim is to develop non-destructive testing methods by which laser hardening parameters as hardness, hardening depth and retained austenite can be determined. Two micromagnetic methods (magnetic Barkhausen noise and incremental permeability) and derived quantities (e.g. the maximum amplitude of the Barkhausen noise and coercivity) are appropriate to determine the above material parameters. (IZFP