ESTIMATION OF SURFACE ABSORPTIVITY AND SURFACE-TEMPERATURE IN LASER-SURFACE HARDENING PROCESS

A two-dimensional, quasi-static, inverse heat conduction problem (IHCP ) is implemented to investigate the absorption efficiency of surface c oatings in laser surface hardening process. The analysis of IHCP inclu des the utilization of the method of direct sensitivity coefficient an d the measurement of interior temperatures nearby the laser heating su rface. The results shows that the estimation of surface absorptivity g enerally agrees with that observed by experimental works. It is realiz ed that the different kinds of coating make influences on the surface absorptivity as well as surface temperature significantly. Furthermore , the power density and scanning speed of laser beam to control the qu ality of surface hardening may be determined based on the informations of heat flow in the workpiece.