Design optimisation of flank wear and surface roughness for CBN-TiN tools during dry hard turning of hot work die steel

In the present study, an attempt has been made to evaluate the performance of CBN-TiN tools during hard turning of hot work die steel. The modelling and optimisation of the flank wear and surface roughness has been made through response surface methodology (RSM) combined with Box-Behnken design (BBD) of experiments. The effect of machining parameters viz cutting speed, feed rate and workpiece hardness on the response factors viz flank wear and surface roughness were investigated by applying ANOVA and through factor interaction graphs in RSM. The experimental data points were observed to be best fitted by non-linear quadratic models. All the factors were found to be statistically significant in determining surface roughness while speed and feed were the dominant factors affecting flank wear. The confirmation experiments carried out to check the validity of developed models predicted response factors with less than 5% error. Scanning electron microscope accompanied with energy dispersive analysis through xs-ray characterised the tool wear conditions. The dominant wear mechanism observed at low speed was the 'abrasive' wear where as at high speed, 'adhesive' wear was dominant. Copyright © 2010 Inderscience Enterprises Ltd.