The effects of Ti and Sn alloying elements on precipitation strengthened Cu4OZn brass using powder metallurgy and hot extrusion

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:535

Article

Li, Shufeng¹  Imai, Hisashi¹  Atsumi, Haruhiko¹  Kondoh, Katsuyoshi¹  Kojima, Akimichi²  Kosaka, Yoshiharu²  Yamamoto, Koji³  Takahashi, Motoi³ 

[1] Osaka Univ, Joining & Welding Res Inst, Suita, Osaka 565, Japan

[2] San Etsu Met Co Ltd, OHTA, Tonami, Toyama, Japan

[3] Nippon Atomized Met Powders Corp, Noda, Chiba, Japan

关键词: Brass;    Spark plasma sintering;    Powder metallurgy;    Extrusion;    Precipitation strengthening;    Solid solution;    Mechanical property;    Phase transformation;   

DOI  :  10.1016/j.msea.2011.12.036

来源: Elsevier

【 摘 要 】

The effects of Ti and Sn alloying elements on the microstructural and mechanical properties of 60/40 brass were studied by powder metallurgy processing. The super-saturated solid solution of Ti creates a high precipitation reaction chemical potential in water-atomized BS40-1.0Ti brass powder. Consequently, BS40-1.0Ti brass was remarkably strengthened by the addition of Ti. However, Ti readily segregated in the primary particle boundaries at elevated temperatures, which detrimentally affected the mechanical properties of BS40-1.0Ti brass. Accordingly. Sn was proposed as an additive to BS40-0.6Sn1.0Ti to inhibit the segregation of Ti. Consequently, the Ti precipitate was retained in the form of CuSn3Ti5 in the interior of grains and grain boundaries rather than in the primary particle boundaries. This result demonstrates that the addition of Sn can effectively hinder Ti segregation in the primary particle boundaries. Sn addition produced significant grain refinement and mechanical strengthening effects in BS40-0.6Sn1.0Ti brass. As a result, outstanding strengthening effects were observed for BS40-0.6Sn1.0Ti sintered at 600 degrees C, which exhibited a yield strength of 315 MPa, an ultimate tensile strength of 598 MPa, and a Vickers microhardness of 216 Hv. These values represent increases of 27.5%, 20.1% and 45.6%, over those of extruded BS40-1.0Ti brass. (C) 2011 Elsevier B.V. All rights reserved.

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