Investigation of the effects of laser surface treatment on wear behavi̇or of ductile cast irons

In this study, the effect of laser surface treatment (LST) on the dry sliding wear behavior of the ferritic GJS 400-18 and the pearlitic GJS 700-2 ductile cast irons was investigated. Within the scope of the study, the microstructures of laser-treated zones were examined after the LST processes to the sample's surfaces using two different laser powers (1450 W and 1600 W) at two different laser scanning speeds (2 mm/s and 4 mm/s), and the surface hardness values were measured. Then, dry sliding wear tests were carried out under two different loads (5N, 10N) and at three different sliding speeds (10 mm/s, 20 mm/s, and 30 mm/s) to examine the effect of LST on the wear behavior of the test samples. After the wear tests, the wear behavior of the samples was evaluated comparatively in terms of COF graphs, volume loss values, specific wear rates, and wear mechanisms. After LST treatments using 1600 W laser power and 2 mm/s laser scanning speed, the highest hardness values measured for the GJS 400-18 and GJS 700-2 samples were determined to be 924 HV0.2 (216 HV0.2 before LST), and 1054 HV0.2 (244 HV0.2 before LST), respectively. As a result, it was determined that the volume loss values for the 431-LSTed and 731-LSTed coded samples could be reduced by approximately 26.6% and 30.7%, respectively, compared to the untreated samples.