Saranjit Singh This email address is being protected from spambots. You need JavaScript enabled to view it.1, A. K. Jha2 and S. Kumar1

1Department of Production Engineering Birla Institute of Technology Mesra Ranchi – 835 215, Jharkhand, India.
2Department of Mechanical Engineering, Institute of Technology Banaras Hindu University Varanasi – 221 005, U.P., India


 

Received: November 7, 2003
Accepted: April 6, 2004
Publication Date: December 1, 2004

Download Citation: ||https://doi.org/10.6180/jase.2004.7.4.05  


ABSTRACT


The upper bound method though an approximate energy method to obtain exact mathematical solutions is still preferred for analysis of metal forming problems. Although much work has been reported on the analysis of sinter-forging of preforms with simple generic shapes such as solid cylindrical discs and rectangular strips, the analysis of sinter-forging of truncated conical preform has not been considered. The present work deals with the upper bound analysis of axi-symmetric high-speed sinter-forging of truncated conical preforms under cold conditions by accounting for an exponential velocity field taking bulging and inertia effects. A generalized expression for average forging load has been established and the effect of taper angle, preform height and interfacial friction conditions at die-workpiece interface during deformation has been critically studied.


Keywords: High-Speed Sinter-Forging; Upper Bound; Truncated Conical Preform; Inertia Effect; Bulging


REFERENCES


  1. [1] Cull, G. W., “Mechanical and Metallurgical Properties of Powder Forging,” Powder Metallurgy, Vol. 13, pp. 156 (1970).
  2. [2] Avitzur, B. et al., “Analysis of plastic flow through inclined planes in plane strain,” Trans. ASME, J. of Engg. Industry, pp. 361375 (1967).
  3. [3] Avitzur, B., “Strain Hardening and Strain-rate Effects in Plastic Flow Through Conical Converging Dies,” Trans. ASME, J. of Engg. for Industry, pp. 556562 (1967).
  4. [4] Avitzur, B., “Limit Analysis of Disk and Strip Forging,” Int. J. of Mach. Tool Design and Res., Vol. 9, pp. 165 (1969).
  5. [5] Avitzur, B., “Metal forming: processes and analysis,” McGraw Hill, New York, (1968).
  6. [6] Kobayashi, S., “Upper Bound Solutions of Axisymmetric Forming problems – I,” Trans. ASME, J. of Eng. for Industry, Vol. 86, pp. 122 (1964).
  7. [7] Yang, D. Y. et al., “An Analysis of Three Dimensional Upset Forging of Elliptical Disks,” Int. J. of Mach. Tool Design and Res., Vol. 26, pp. 147 (1986).
  8. [8] Jha, A. K. et al., “Forging of Metal Powder Preforms,” Int. J. of Mach. Tool Design and Res., Vol. 23, p. 201 (1983).
  9. [9] Kumar, S., “Principles of Metal Working,” Oxford/ IBH, New Delhi, India, (1976).
  10. [10] Jha, A. K. et al., “Production of Sinter-forged Components,” J. of Materials Process. Tech., Vol. 41, pp. 143169 (1994).
  11. [11] Jha, A. K. et al., “Compatibility of Sintered Materials During Cold Forging,” Int. J. of Materials and Product Tech., Vol. 9, pp. 281299 (1994).
  12. [12] Sutradhar, G., “Cold Forging of Sintered Polygonal Discs,” J. of I.E. (India), Vol. 76, pp. 148152 (1995).
  13. [13] Jha, A. K. et al., “Investigations into the High-speed Forgings of Sintered Copper Powder Strips,” J. of Materials Process. Tech., Vol. 71, p. 394 (1997).
  14. [14] Jha, A. K. et al., “Dynamic Effects during High-speed Sinter-forging Process,” Int. J. of Mach. Tools and Manuf., Vol. 36, p. 1109 (1996).
  15. [15] Tabata, T., “A compression test to determine the coefficient of friction in forging P/M preforms,” Int. J. of Powder Metall. and Powder Tech., Vol. 16, p. 149 (1980).
  16. [16] Tabata, T., “Estimation of Flow Stress of Porous Sintered Metals from Hardness Test with Pyramidal and Spherical Indenters,” J. of Eng. Materials and Tech., Vol. 112, pp. 9598 (1990).
  17. [17] Avitzur, B. et al., “Disk and Strip Forging with Sidesurface Fold over: Velocity Field and Upper Bound Analysis,” Trans. ASME, J. of Engg. for Industry, Vol. 100, pp. 421427 (1978).
  18. [18] Avitzur, B. et al., “Disk and Strip Forging with Side-surface Fold over: Evaluation of Upper Bound Solutions,” Trans. ASME, J. of Engg. for Industry, Vol. 100, pp. 428433 (1978).
  19. [19] Singh, S. et al., “Analysis of Dynamic Effects During High-speed Forging of Sintered Preforms,” J. of Materials Process. Tech., Vol. 112, pp. 5362 (2001).
  20. [20] Sahoo, S. K. et al., “Forging of a Truncated Cone: An Upper Bound Analysis,” AIMTDR Proceedings, Vol. 20, pp. 414420 (2003).