| Popis: |
This paper presents the mathematical model for modelling and predicting the core roughness depth (Rk parameter) during hard turning with ceramic inserts, using nonlinear function shape and a four-factorial plan experiments of the first order. The independent mathematical modelling input parameters comprise cutting speed (v), feed (f), tool nose radius (re) and depth of cut (ap), with repetition in the middle point of the investigated hyperspace. The research was carried out on working rings made of the steel C 55 (DIN), thermally enhanced on a 52 ± 2 HRC, while the processing was done on the CNC lathe model OKUMA LB 15-II (C-1S). The measurement of working rings, obtaining the roughness profile and calculation of the Rk parameters is done using the instrument Surtronic 3+ and the Talyprofile software. The results of the research are presented by nonlinear mathematical models for the Rk parameter and coefficient KRk obtained from the ratio between Rk and the sum of Rpk, Rk and Rvk. According to the obtained mathematical models, 3D graphs of the dependences between the Rk parameter, coefficient KRk and the input independent variables are also shown. The obtained mathematical models are explained, and appropriate conclusions are given. |
