Improving tensile properties of dilute Mg-0.27Al-0.13Ca-0.21Mn (at.%) alloy by low temperature high speed extrusion

JOURNAL OF ALLOYS AND COMPOUNDS

卷:648

Article

Nakata, T.¹  Mezaki, T.¹  Xu, C.¹  Oh-ishi, K.¹  Shimizu, K.²  Hanaki, S.²  Kamado, S.¹ 

[1] Nagaoka Univ Technol, Nagaoka, Niigata 9402188, Japan

[2] Sankyo Mat Co, Sankyo Tateyama Inc, Imizu, Toyama 9348515, Japan

关键词: High-speed extrusion;    Mg-Al-Ca-Mn alloy;    Dynamic recrystallization;    Texture;    Tensile properties;   

DOI  :  10.1016/j.jallcom.2015.07.051

来源: Elsevier

【 摘 要 】

As-cast Mg-0.27Al-0.13Ca-0.21Mn (at.%) alloy was extruded at temperatures from 350 degrees C to 500 degrees C. We examined the microstructural changes during extrusion at different temperatures to clarify dynamic recrystallization mechanisms during extrusion, and also investigated the effect of extrusion temperature on microstructures and mechanical properties of the alloy. High extrusion exit speed of 60 m/min was successfully achieved at wide range of temperatures from 350 degrees C to 500 degrees C even when as-cast dilute Mg0.27Al- 0.13Ca-0.21Mn (at.%) alloy was used as a billet for the extrusion. The extrusion at low temperature refines grain size and weakens basal texture due to continuous dynamic recrystallization (CDRX) together with double twinning. As a result, the alloy sample extruded at 350 degrees C exhibits higher tensile proof stress of 206 MPa and higher tensile ductility of 29% than T5-treated 6063 aluminum alloy and commercial AZ31 magnesium alloy even in an as-extruded condition. Furthermore, Hall-Petch coefficient for compressive proof stress is 1.8 times larger than that for tensile one, resulting in improvement of yield stress anisotropy (compressive proof stress/tensile yield stress ratio). (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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