Civil Engineering Reference
In-Depth Information
performed on the force position data acquired from the testing machine. The fol-
lowing conclusions can be drawn from the research:
• The speciic heat of a material must be considered when modeling EAF. The
effect that the specific heat has on the ability to model EAF is proportional to
the sensitivity of the specific heat value with respect to temperature.
• When modeling EA forging, the all-inclusive heat transfer model could be sim-
plified by neglecting both the radiation and convection heat transfer. This sim-
plification is only valid for EA forging. Alternative EA processes, such as EA
stretch forming or EA bending, may require including the other forms of heat
transfer since the exposed surfaced area is typically greater in comparison with
the total volume of the workpiece.
• Different metals produce different EEC proiles when the EAF technique
is used on them during a forging process. The differences include the overall
shape of the profile (the profile could be concave, convex, etc.); this shape deter-
mines the overall efficiency of the applied electrical power throughout the dura-
tion of the process.
• The frequency analysis indicated that there are speciic frequencies dependent
on the magnitude of the current density applied. The frequency increases with
the current density, thus with energy input. This may be an indication of a cyclic
softening/hardening phenomenon present during EAF.
• The frequency observed for titanium is higher than that for SS304. This could
be due to any differences in the crystalline structure or specific alloying compo-
nents within the metals.
• The quality of the electrical power output during an EAF process can vary
depending on the capabilities of the power source. This can also have an impact
on the mechanical profiles of the same parts undergoing the same EAF process.
References
1. Bunget C, Salandro WA, Mears L, Roth JT (2010) Energy-based modeling of an electri-
cally-assisted forging process. Transactions of the North American Manufacturing Research
Institute of SME, 38
2. Lange K (1985) Handbook of metal forming. McGraw-Hill, New York
3. Backofen WA (1972) Deformation processing. Addison-Wesley Educational Publishers Inc,
Boston
4. Kobayashi S, Oh S-I, Altan T (1989) Metal forming and the finite-element method. Oxford
University Press, New York
5. Wagoner RH, Chenot JL (1996) Fundamentals of metal forming. Wiley, Hoboken
6. Perkins TA, Kronenberger TJ, Roth JT (2007) Metallic forging using electrical flow as an
alternative to warm/hot working. J Manuf Sci Eng 129(1):84-94
7. Avitzur B (1980) Metal forming: the application of limit analysis. Dekker, New York
8. Cengel YA (2007) Heat and mass transfer: a practical approach, 3rd edn. McGraw-Hill
9. Cengel YA, Boles MA (2008) Thermodynamics: an engineering approach, 6th edn.
McGraw-Hill
10. Ross CD, Irvin DB, Roth JT (2007) Manufacturing aspects relating to the effects of DC
current on the tensile properties of metals. J Eng Mater Technol 129(2):342-347
