Journal Published Online: 05 September 2019
Volume 8, Issue 1

Measurement and Prediction of Temperature Increase during Isothermal Forging of Titanium–6 Aluminum–4 Vanadium

CODEN: MPCACD

Abstract

Titanium–6 aluminum–4 vanadium is isothermally forged at 1,023–1,223 K (750°C–950°C) at 0.05, 0.1, and 1.0/s using a 1,500-ton forging press simulator. The temperature increase of a workpiece (100 mm in diameter, 50 mm in height) during forging is measured by inserting thermocouples into the workpiece, and this increase is predicted using finite element analysis (FEA). The physical properties necessary for the FEA are determined using the same material as the forged one in order to improve the prediction accuracy. The true stress–true strain curves and heat transfer coefficient between the workpiece and dies are inversely obtained. The temperature change predicted by FEA using those parameters and curves agreed well with the experimental results. In the FEA, the inelastic heat fraction, which is a conversion factor for plastic deformation energy to heat energy, did not depend on the strain rate, but it remained the same at strain rates of 0.05–1.0/s. This result suggests that the large heat capacity of the workpiece in this study suppressed the effect of heat transfer between the workpiece and dies/air on the temperature of the workpiece. It is also shown that the prediction accuracy of the workpiece’s temperature could be degraded unless the appropriate specific heat value is used, especially near the β transus temperature, which can be affected by the composition of light elements.

Author Information

Kitashima, T.
Research Center for Structural Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
Matsumoto, R.
Division of Materials and Manufacturing Science, Osaka University, Suita, Osaka, Japan
Yoshida, Y.
Mechanical and Systems Engineering Division, Gifu University, Gifu City, Gifu, Japan
Matsumoto, H.
Division of Advanced Materials Science, Kagawa University, Takamatsu, Kagawa, Japan
Nishihara, T.
Japan Aeroforge, Ltd., Kurashiki, Okayama, Japan
Kuroda, S.
Research Center for Structural Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
Motohashi, N.
Research Center for Structural Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
Hagiwara, M.
Research Center for Structural Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
Emura, S.
Research Center for Structural Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
Pages: 13
Price: $25.00
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Details
Stock #: MPC20190075
ISSN: 2379-1365
DOI: 10.1520/MPC20190075