TY JOUR TI DYNAMICS OF FIVE-AXIS END MILLING PROCESS KW five-axis end milling KW free-form surfaces KW cutting forces KW ball end mills KW tool orientation KW machining conditions JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Ponomarev, B.B. AU Nguyen, H.S. PY 2019 IS 4 PB Belgorod State Technological University named after V.G. Shukhov