Transactions of Materials Processing (소성∙가공)

The Korean Society for Technology of Plasticity and materials processing (한국소성∙가공학회)
권호 표지
DOI QR코드

DOI QR Code

Assessment of Forming Defects in Hot Backward Extruded Ti-6Al-4V Tubes using Dynamic Materials Model

동적재료모델을 활용한 열간 후방압출된 Ti-6Al-4V튜브의 성형결함 해석

  • Published : 2003.10.01
Download PDF
⟨ Previous Next ⟩

Abstract

The metal forming behavior and defect formation in Ti-6Al-4V tube during hot backward extrusion were investigated. Dynamic material model(DMM) including Ziegler's instability criterion was employed to predict the forming defects such as shear band, inner and/or surface cracks. This approach was coupled to the internal variables generated from FE analysis. The simulation results fur the backward extrusion were compared with the experimental observation. The chilling effect and friction indicated a great influence on the deformation mode of the tube and the formation of surface cracks. The formation of forming defects in the extruded tube was attributed to non-uniform distribution of strain, strain rate and temperatures in the extruded tubes for the given test conditions.

Keywords

References

  1. Semiation, S. L., Seetharaman, V. Weiss, I., 1998, "Hot workability of titanium and titanium aluminide alloys, Mater. Sci. Eng. A243, pp. 1-24.
  2. Udagawa, T., Kropp, E., and Altan, T., 1992, "Investigation of metal flow and temperatures by FEM in the extrusion of Ti-64 tubes", J. Mater. Proc. Tech., Vol.33,pp. 155-174. https://doi.org/10.1016/0924-0136(92)90317-L
  3. Y.V.R.K. Prasad and S. Sasidhara, 1997, "Hot Working Guide", ASM International.
  4. Y.V.R.K. Prasad, T. Seshacharyulu, S. C. Medeiros, W.G. Frazier, "Influence of oxygen content on the forging response of equiaxed ($\alpha$+$\beta$) perform of Ti-6Ai-4V", J. Mater. Proc. Tech., Vol.108, pp. 320-327. https://doi.org/10.1016/S0924-0136(00)00832-3
  5. 염종택, 김두현, 나영상, 박노광, 2001, "Ti6Al-4V 합금의 고온변형거동 규명", 한국소성가공학회지, 제 10 권, 제 4 호, pp. 347-354.
  6. Park, N. K. Yeom J. T., Na Y. S., 2002, "Characterization of deformation stability in hot forging of conventional Ti-64 using processing maps", J. Mater. Proc. Tech., Vol.130-131, pp. 540-545. https://doi.org/10.1016/S0924-0136(02)00801-4
  7. 염종택, 임정숙, 나영상, 박노광, 신태진, 황상무, 심인옥, 2003, "Ti-64-4V 합금의 열간성형공정에 대한 계면열전달계수의 결정", 한국소성가공학회 2003 년도 춘계학술대회논문집, pp. 299-302.
  8. Prasad, Y., Gegel, H. L., 1984, "Modeling of dynamic material behavior in hot deformaticon : forging of Ti-6242, Metall. Trans. A15, pp. 1883-1892.
  9. Ziegler, H., 1965, "Some extremum principles in irreversible thermodynamics with application to continuum mechanics", in Prog. Solid Mech., Sneddon, I.N., and Hill, R.(eds.), Vol. 4, Wiley, New York,p.93.