Thermal coupling coefficient of metal material to CW IR laser

Using a integrating sphere designed by ourselves,we measured the thermal coupling coefficients of several kinds of LY12 Al alloy targets having different surface situations to CW CO2 laser beam(the power is about 40W).The experiment results show the fact that the test values are bigger than the calculation values by the classical theory.This paper presented the analysis to the fact,and points out the surface defects will much increase the thermal coupling coefficient.