[1] Tohoku Univ, Dept Mat Proc, Grad Sch Engn, Aoba Ku, Sendai, Miyagi 9808579, Japan
[2] Hitachi Ltd, Mat Res Lab, Hitachi, Ibaraki 3191292, Japan
[3] Hitachi Amer Ltd, Automot Prod Res Lab, Div Res & Dev, Farmington Hills, MI 48335 USA
[4] Gen Motors R&D Ctr, Mfg Proc Lab, Warren, MI 48090 USA