Vibration analysys

ARTICLE IN PRESS
International Journal of Machine Tools & Manufacture 50 (2010) 65–74

Contents lists available at ScienceDirect

International Journal of Machine Tools & Manufacture journal homepage: www.elsevier.com/locate/ijmactool

Vibration analysis of cutting force in titanium alloy milling
Armando 
Italo Sette Antonialli a,Ã, Anselmo Eduardo Diniz b,1, Robson Pederiva b,1 a b

~
~
Materials Engineering Department, Federal University of Sao Carlos, 13565-905 Sao Carlos, SP, Brazil
Faculty of Mechanical Engineering, State University of Campinas, C. Postal 6122, 13083-860 Campinas, SP, Brazil

article info

abstract

Article history:
Received 16 June 2009
Received in revised form
1 September 2009
Accepted 8 September 2009
Available online 16 September 2009

Machining processes such as milling, which are characterized by interrupted cutting, are often susceptible to problems involving vibration of the machine-tool-workpiece fixation device system because of the proximity between their natural frequency harmonics and the frequency of tool entry on the workpiece. This phenomenon is particularly important in the milling of titanium alloys, because these materials show a low Young modulus, and hence, an extended elastic behavior, which means tremendous variations in chip thickness and fluctuating cutting forces. Moreover, very low heat conductivity causes the formation of serrated chips, which further increase the fluctuation in cutting forces. The purpose of this work is to study the influence of the tool entering angle on the stability of the process and on tool life based on a time and frequency domain analysis of the cutting forces. The results show that lower entering angles may provide stabler cutting, as indicated by the regular tool wear instead of the microchipping resulting from the use of a higher value of this angle. Although cutting forces are larger at lower entering angles, the tool life is much longer, since most