THE TAGUCHI METHOD FOR DETERMINING CO2-LASER CUT QUALITY

The rapid growth in the application of lasers as a cutting tool has ge nerated considerable interest in the quality of the cut edges produced . Consequently, the present study is conducted to assess cut edge qual ity, by defining the measurable variables, using international standar ds for thermal cutting. The measurable variables defining the cut edge s may include waviness and flatness. Cutting speed, oxygen pressure, a nd workpiece thickness are considered as cutting parameters, therefore the Taguchi method is used to classify the relevant parameters. The s tudy is extended to include the detection of light emission from the s urface plasma. This makes it possible to monitor temporal behavior of the surface plasma, which in turn gives information about the formatio n of striations. Scanning electron microscope microphotography is cond ucted to examine the resulting cut surfaces. It is found that the cut quality is mainly affected by the oxygen gas pressure and cutting spee d. However, flatness depends significantly on the thickness. Microcrac ks appear on the cut edge surfaces due to rapid solidification of the molten oxide layer formed on the surface. (C) 1998 Laser Institute of America. [S1042-346X(98)00501-4].