Cyclical Chips Formation during Machining of Titanium and Titanium Alloys

Authors

  • O. O. Awopetu Mechanical Engineering Department, The Federal University of Technology, Akure

Keywords:

Titanium, cyclical chip, tool wear, machining, shear plane, plasticity

Abstract

Turning of titanium alloys which is characterized with low cutting speeds and high tool wear, poses considerable problems due to the poor machinability of titanium. In this work, the process of cyclical chip formation during machining of titanium and titanium alloys was studied and analysed. Titanium alloys of BT1.00, BT3-1 and BT-5.1, of diameter 100 – 200 mm and length 600 – 800 mm, was used as the work piece. Experimental results show that the width of chip formation zone during cutting of titanium alloys is very minimal. As a result of this, increasing the plasticity (elasticity) properties of volumes of titanium alloys lead to the ceasing of the formation of cyclical chips. This study has however analysed and pointed out that the best wear resistant cemented carbide tool was BK6 and cemented carbide tool BK8 was only 75 - 80% as good. At a cutting speed V = 60 m/min, a durability of S30 minutes was attained. The durability increased to 45 – 50 minutes when the cutting speed was reduced to V = 50 m/min and a stable wear of 0.30 - 0.35 min was maintained for about 70% of the working period. Majority of the chip elements increased in the width of localized shear plane and the contact layer with increase in cutting speeds.

References

Awopetu O.O, Dahunsi O.A and Aderoba A.A (1995), “Selection of Cutting Tools for Turning α-Titanium Alloy BT-5”. AU journal, pp 196-202.

Ezugwu E.O. and Wang Z.M. (1997), “Titanium alloys and their machinability-a review”. Journal of Materials Processing Technology 68, pp 262-274.

Ozel T., Sima M., Srivastava A.K and Kaftanoglu B. (2010), “Investigations on the effects of multi-layered coated inserts in machining Ti–6Al–4V alloy with experiments and finite element simulations”. CIRP Annals - Manufacturing Technology 59, pp 77–82

Sun S, Brandt M. and Dargusch M.S (2009), “Characteristics of cutting forces and chip formation in machining of titanium alloys”. International Journal of Machine Tools & Manufacture 49, pp 561–568.

Srivastava A.K, Xupeing S., Bell T and Steve C (2001), "Investigations on turning Ti-6Al-4V titanium alloy using super-finished tool edge geometry generated by micro-machining process (MMP)” Shanghai Jiao Tong University, Shanghai, PRC.

Veiga C., Davim J.P. and Loureiro A.J.R. (2013), “Review on Machinability of Titanium Alloys: The Process Perspective. Rev. Advance Material Science. 34 (2013), pp148 – 164

Gao Y. Wang G. and Liu B. (2016). Chip Formation Characteristics in the Machining of Titanium Alloys: A Review. International Journal of Machining and Machinability. Vol. 18, Issue 1 – 2, pp 155 – 184.

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Published

2019-05-03