Control of laser surface alloying

It is well known that the results of laser surface treatment may vary significantly even
under apparently constant processing conditions. This is due to the high sensitivity of
laser surface treatment to process disturbances. As a result, the desired temperature cycle and temperature distribution of the work piece is perturbed, which may induce
unacceptable process errors.
The major process disturbances are varying absorptivity A and a complex work piece geometry.
The absorptivity of metals for CO, laser radiation may vary considerably during
processing [1 ]. This perturbs the temperature cycle significantly.
When a work piece with small dimensions (e.g. a thin wall) is treated the self quenching capacity is reduced. This also results in a perturbation of the temperature cycle. An approach is to consider the geometry as semi-infinite and the perturbations due to geometrically small dimensions as process disturbances.