Estimating the remaining useful tool life of worn tools under different cutting parameters: A survival life analysis during turning of titanium metal matrix composites (Ti-MMCs)

Utilizing the full tool life capacity of cutting tools has always been a concern, due to the considerable costs associated with suboptimal replacement of tools. Reliable reuse of worn inserts could significantly reduce machining costs. This study aims at estimating the remaining useful life of worn cutting inserts under multiple cutting parameters during turning of Ti-MMCs, using the actual tool wear value of the worn tool as the input data. A proportional hazards model with a Weibull baseline is developed. Maximum flank wear length at the transition point between the second and third state of tool wear is chosen as the failure criteria. Tool wear, cutting speed and feed rate are considered as the covariates of the model. The reliability and hazard functions are calculated from the model and are utilized to obtain the mean residual life of inserts under different cutting parameters and tool wear levels. The accuracy of the model is validated using experimental data. The results confirmed the validity and reliability of the model.