Materials Transactions Online

Materials Transactions, Vol.48 No.09 (2007) pp.2539-2541
© 2007 The Japan Institute of Metals

Enhanced Grain Refinement by Mechanical Twinning in a Bulk Cu-30 mass%Zn during Multi-Directional Forging

H. Miura, Y. Nakao and Taku Sakai

Department of Mechanical Engineering and Intelligent Systems, UEC Tokyo (The University of Electro-Communications), Tokyo 182-8585, Japan

A bulk Cu-Zn alloy was multi-directionally forged at 77 K and 300 K to a cumulative strain of ΣΔε = 6.0. With increasing strain, the initial grains subdivided gradually to ultrafine grains. Mechanical twins enhanced the grain fragmentation. The formed twins were further subdivided by the other variants of twins. The grain size obtained at ΣΔε = 6.0 was about 17 nm at 77 K and 26 nm at 300 K.

(Received 2007/5/29; Accepted 2007/6/21; Published 2007/8/10)

Keywords: twinning, multi-directional forging, ultrafine grain, copper-zinc alloy

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