Compaction of Ti-6Al-4V Powder by ECAE with Back-Pressure


Article Preview

Powder metallurgy is widely used to produce alloys with low cost of production. The main drawback using powders is the level of residual porosity of final product which often implies the application of a complicated and costly hot isostatic pressing process. However, this issue can be overcome by using equal channel angular pressing (ECAE) with back pressure (BP). The use of severe shear deformation, with imposed hydrostatic pressure, allows a reduction in the range of compaction temperatures compare to those used in conventional practice. The compaction of Ti-6Al-4V powder by the ECAE method has been investigated. The compaction has been performed at temperatures starting from room temperature (RT) and increasing up to 400°C with various back pressures ranging from 0 to 350MPa. A billet processed by ECAE with 43MPa back-pressure at 400°C was found to have improved relative density of 97.5% and increased Vickers hardness of 369HV, compared to values of 96.7% and 325HV respectively obtained at RT. A relative density of 98.2% and 426HV hardness were measured for billets processed with BP = 262MPa at 400°C. A fully compact billet was obtained by applying 350 MPa of BP at 400°C.



Advanced Materials Research (Volumes 29-30)

Edited by:

Deliang Zhang, Kim Pickering, Brian Gabbitas, Peng Cao, Alan Langdon, Rob Torrens and Johan Verbeek




R. Lapovok et al., "Compaction of Ti-6Al-4V Powder by ECAE with Back-Pressure", Advanced Materials Research, Vols. 29-30, pp. 33-36, 2007

Online since:

November 2007




[1] Jim Williams, J. of Materials Processing Technology, 117 (2001), pp.370-373.

[2] C.A. Kelto, B.A. Kosmal, D. Eylon, F.H. Froes, in: Powder Metallurgy of Titanium Alloys, 1980, The Metallurgical Society of AIME, pp.1-19.

[3] M. Hagiwara, S.J. Kim, S. Emura, Scripta Materialia, 39: 9 (1998), 1185 - 1190.

[4] T. C. Lowe, R. Z. Valiev, JOM. April (2000), p.27.

[5] R. Lapovok, Journal of Materials Science, 40: 2, (2005), pp.341-346.

[6] J. Robertson, J. -T. Im, I. Karaman, K.T. Hartwig, I.E. Anderson, Journal of Non-crystalline Solids 317 (203), 144-151.

[7] R. Lapovok, P.F. Thomson, in: Nanomaterials by Severe Plastic Deformation: Fundamentals - Processing - Applications, Eds. M. Zehetbauer, R.Z. Valiev, (2003), Wiley Germany, 551-557.