In this paper, a proof of time-dependent behavior of heat flux into a cutting tool is built. Its implementation calls for a new method for estimating heat flux, which was developed using an inverse problem technique. A special experimental setup was designed and manufactured to implement the method. A series of dry machining experiments were conducted with high speed steel and cemented carbide tooling. A two-stage procedure was developed to overcome the ill-posedness of the inverse heat conduction problem by transforming it into a well-posed parameter estimation problem. The first stage retrieves the value of the heat flux and specific tool heating energy Et. The second stage parametrizes and compares predefined heat flux behaviors. It was found that the time dependency of heat flux is best described by a decreasing power function.

No abstract

In this study the cutting tool temperature that develops during rough turning of hardened cold-work tool steel is modelled on the basis of experimental data. The data obtained from a series of thermocouples, placed on a PCBN insert, into an anvil, and into a toolholder, were used as the input for the model. An inverse problem was solved, where the heat fluxes and heat transfer coefficients were computed and where the developed temperature field was reconstructed from the experimental readings. The temperature was modelled for the case of new tools, as well as for the case of its development in the course of tool wear. The machining case involved utilization of a high-cBN content and a binderless PCBN grade, both possessing high thermal conductivity of 110 and 190 W/m K respectively.

No abstract