Mechanistic model validation for specific cutting pressure prediction during micromilling of superduplex stainless steel UNS S 32750
Vanessa da Silva Pinheiro1; Adriane Lopes Mougo2; Anna Carla Araujo3
1 Departamento de engenharia mecânica-UFRJ; 2 Departamento de Engenharia Mecânica-COPPE/UFRJ; 3 Departamento de engenharia Mecânica -COPPE/UFRJ
doi:10.20906/CPS/COB-2015-1637
Resumo
The predictive models of performance of the machining processes are important tools for the development and integrated to manufacturing. Without these models, planning and experimental tests in machining become extremely expensive because changing any of the input parameters can cause errors and damages to the process. Cutting force has attracted constant attention of researchers, as this parameter is useful to analyze tool life, work piece quality and other factors related to equipment and machine-tool project. These conventional models of cutting forces were adapted to the micro scale process considering geometric characteristics, dynamics and cutting parameters and microstructure to calculate the specific cutting pressure for each tool-piece pair. Both mechanistic and experimental models predict the specific cutting pressure through experimental data. These results are used for the prediction of cutting forces in micromilling process. This way, the main objective of this work is to calibrate a mechanistic model determining the specific cutting pressure coefficients using experimental data and, then, validate this model comparing the specific pressure values computed with the experimental ones. The material used in this work is the superduplex stainless steel UNS S 32750. This steel presents a bi-phasic microstructure with different mechanical and chemical properties. This can cause variations on the cutting dynamics of the micro tool when the passage of the tool tooth occur one time in a ductile phase and then in a brittle phase. The Design of Experiments used two levels of cutting speed and four levels of feed rate, maintaining a constant depth of cut and cutting fluid as coolant. The validation results showed a maximum error between the experimental and simulated values of the specific cutting pressure of 6.33%.
Palavras-chave: micromilling; superduplex UNS S32750; mechanistic model; validation; specific cutting pressure