Metallurgical study on chips obtained by high speed machining of a Ti–6 wt.%Al–4 wt.%V alloy

Abstract A metallurgical analysis on chips obtained by high speed machining of a Ti–6wt.%Al–4wt.%V alloy has been performed to provide a better understanding of chip formation mechanisms. For this purpose, X-ray diffraction, energy dispersive X-ray analysis, scanning electron microscopy and electron backscattering technique were employed. The titanium β phase was observed in all chips for any tested cutting speeds. No evidence of phase transformation was found in the shear bands. Microscopical observations are in agreement with the catastrophic thermoplastic shear model for saw-tooth chip formation, instead of the periodic crack initiation one.

[1]  Z. M. Wang,et al.  Titanium alloys and their machinability—a review , 1997 .

[2]  Gérard Poulachon,et al.  A Contribution to the Study of the Cutting Mechanisms During High Speed Machining of Hardened Steel , 1998 .

[3]  Minjie Wang,et al.  Characteristics of adiabatic shear bands in the orthogonal, cutting of 30CrNi3MoV steel , 2005 .

[4]  R. Komanduri,et al.  New observations on the mechanism of chip formation when machining titanium alloys , 1981 .

[5]  Kazuo Nakayama,et al.  Machining Characteristics of Hard Materials , 1988 .

[6]  Matthew A. Davies,et al.  On repeated adiabatic shear band formation during high-speed machining , 2002 .

[7]  P. Chevrier,et al.  Investigation of surface integrity in high speed end milling of a low alloyed steel , 2003 .

[8]  S. L. Semiatin,et al.  Shear localization during metal cutting , 1983 .

[9]  Janez Kopac,et al.  A contribution to the understanding of chip formation mechanism in high-speed cutting of hardened steel , 2004 .

[10]  A. Molinari,et al.  Adiabatic shear banding in high speed machining of Ti-6Al-4V: experiments and modeling , 2002 .

[11]  M. C. Shaw,et al.  Mechanics of Saw-Tooth Chip Formation in Metal Cutting , 1999 .

[12]  R. Komanduri,et al.  Modeling of thermomechanical shear instability in machining , 1997 .

[13]  R. Shivpuri,et al.  Prediction of chip morphology and segmentation during the machining of titanium alloys , 2004 .

[14]  Minjie Wang,et al.  Some metallurgical aspects of chips formed in high speed machining of high strength low alloy steel , 2005 .

[15]  M. C. Shaw,et al.  Chip Formation in the Machining of Hardened Steel , 1993 .

[16]  R. Recht.  Catastrophic Thermoplastic Shear , 1964 .

[17]  M. Elbestawi,et al.  A Model for Chip Formation During Machining of Hardened Steel , 1996 .

[18]  Matthew A. Davies,et al.  On Chip Morphology, Tool Wear and Cutting Mechanics in Finish Hard Turning , 1996 .

[19]  Guy Sutter,et al.  Chip geometries during high-speed machining for orthogonal cutting conditions , 2005 .

[20]  A. Bayoumi,et al.  Some metallurgical aspects of chip formation in cutting Ti-6wt.%Al-4wt.%V alloy , 1995 .

[21]  M. C. Shaw,et al.  Mechanics of Machining: An Analytical Approach to Assessing Machinability , 1989 .

[22]  D. G. Flom,et al.  On the Catastrophic Shear Instability in High-Speed Machining of an AISI 4340 Steel , 1982 .

[23]  G. Byrne,et al.  The mechanisms of chip formation in machining hardened steels , 2002 .

[24]  W. König,et al.  Turning versus grinding: a comparison of surface integrity aspects and attainable accuracies , 1993 .

[25]  Matthew A. Davies,et al.  On the Dynamics of Chip Formation in Machining Hard Metals , 1997 .

[26]  S. Timothy,et al.  The structure of adiabatic shear bands in metals: A critical review☆ , 1987 .

[27]  G. Byrne,et al.  Observations on chip formation and acoustic emission in machining Ti–6Al–4V alloy , 2001 .