Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-28T02:02:56.598Z Has data issue: false hasContentIssue false
  • English
  • Français

Shear Melting and High Temperature Embrittlement: Theory and Application to Machining Titanium

Published online by Cambridge University Press:  14 July 2016

Graeme J Ackland ,
Con Healy ,
Sascha Koch ,
Florian Brunke  and
Carsten Siemers
Graeme J Ackland*
Affiliation:
School of Physics, University of Edinburgh, Edinburgh EH9 3FD Scotland, UK.
Con Healy
Affiliation:
School of Physics, University of Edinburgh, Edinburgh EH9 3FD Scotland, UK.
Sascha Koch
Affiliation:
School of Physics, University of Edinburgh, Edinburgh EH9 3FD Scotland, UK.
Florian Brunke
Affiliation:
Technische Universitaet Braunschweig. IfW, Langer Kamp 8, 38106 Braunschweig, Germany
Carsten Siemers
Affiliation:
Technische Universitaet Braunschweig. IfW, Langer Kamp 8, 38106 Braunschweig, Germany
*
*(Email: [email protected])
Get access

Abstract

We show that alloying with rare earth metals (REMs) can dramatically improve the machineability of a range of titanium alloys, even though the REM is not incorporated in the alloy matrix. The mechanism for this is that under cutting, shear bands are formed within which the nano-precipitates of REM are shear mixed. This lowers the melting point such that the mechanism of deformation changes from dislocation mechanism to localised amorphisation and shear softening. The material then fractures along the thin, amorphous shear-band. Outside the shear band, the REM remains as precipitates. The new alloys have similar mechanical properties and biocompatibility to conventional materials.

Keywords

machiningTiLa
Type
Articles
Information
MRS Advances , Volume 1 , Issue 35: Materials Design , 2016 , pp. 2477 - 2482
Copyright
Copyright © Materials Research Society 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Lutjering, G. & Williams, J.C. (2007). Titanium. Berlin, Germany: Springer.Google Scholar
Siemers, C., Laukart, J., Zahra, B., Rosler, J., Spotz, Z., & Saksl, K. (2010). Development of advanced and free-machining titanium alloys. In: Gallienne, D., Bilodeau, M. (Eds.) 49th Conference of Metallurgists, Light Metals 2010 (pp. 311–322), Vancouver, Canada: CIMMP Google Scholar
Hou, Z.B. & Komanduri, R. (1997). Modelling of thermomechanical shear instability in machining. International Journal of Mechanical Sciences, 39 (11), 1273–1314.Google Scholar
Obikawa, T, Anzai, M., Egawa, T., Narutaki, N., Shintani, K. & Takeoka, E. (2011). High Speed Machining: A Review from a Viewpoint of Chip Formation. Advanced Materials Research, 188, 578–583.Google Scholar
Healy, C., Koch, S, Siemers, C., Mukherji, D. & Ackland, G.J. (2015). Shear melting and high temperature embrittlement: Theory and application to machining titanium, Physical Review Letters 114 (16), 165501.Google Scholar
Siemers, C., Jencus, P., Baeker, M., Roesler, J. & Feyerabend, F. (2007). A new free machining titanium alloy containing lanthanum. In: Niinomi, M., Akiyama, S., Hagiwara, M., Ikeda, M. & Maruyama, K. (Eds.), Eleventh World Conference on Titanium (pp. 709–712). Kyoto, Japan: The Japan Institute of Metals.Google Scholar
Ackland, G. J., D'Mellow, K., Daraszewicz, S. L., Hepburn, D. J., Uhrin, M. and Stratford, K. (2011) The MOLDY short-range molecular dynamics package Computer Physics Comms 182, 2587.CrossRefGoogle Scholar
Healy, C., & Ackland, G.J. (2015). Molecular dynamics simulations of compression–tension asymmetry in plasticity of Fe nanopillars Acta Materialia 70, 105–112 Google Scholar
Li, J. (2003) AtomEye: an efficient atomistic configuration viewer, Modelling Simul. Mater. Sci. Eng, 11, 173 Google Scholar
Stukowski, A. and Albe, K (2010) Extracting dislocations and non-dislocation crystal defects from atomistic simulation data Modelling and Simulation in Materials Science and Engineering, 18, 085001Google Scholar
Peters, M. & Leyens, C., Eds. (2002). Titanium and titanium alloys. Weinheim, Germany: Wiley-VCH.Google Scholar
Tegner, B. E., Zhu, L., & Ackland, G. J. (2012). Relative strength of phase stabilizers in titanium alloys. Physical Review B, 85, 214106.CrossRefGoogle Scholar
Feyerabend, F., Siemers, C., Willumeit, R & Rosler, J. (2009). Cytocompatibility of a free machining titanium alloy containing lanthanum, Journal of Biomedical Materials Research A, 90A, 3, 931–939.Google Scholar
Siemers, C., Bäker, M., Mukherji, D. & Rösler, J. (2003). Microstructure evolution in shear bands during the chip formation of Ti 6Al 4V. In: Lütjering, G. & Albrecht, J. (Eds.). Tenth World Conference on Titanium (pp. 839–846). Hamburg, Germany: Wiley VCH.Google Scholar