Fatigue Property of Single-Crystal and Columnar-Grained Polycrystalline Cu-12wt. % Al Alloys

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• 作者：Haiyou Huang ; Mingjun Nie ; Yanyan Luan ; Xuefeng Liu ; Jianxin Xie ; ^{jxxie@mater.ustb.edu.cn}
• 关键词：Cu-12wt. % Al alloy ; Ohno continuous casting ; columnar-grained polycrystal ; Fatigue property
• 刊名：Procedia Engineering
• 出版年：2012
• 出版时间：2012
• 年：2012
• 卷：27
• 期：Complete
• 页码：1686-1693
• 全文大小：678 K

文摘

In this paper, the tensile mechanical properties and fatigue strengths of single-crystal and columnar-grained polycrystalline Cu-12wt. % Al alloy rods prepared by Ohno continuous casting (OCC) technology were investigated and compared with those properties of polycrystalline Cu-12wt. % Al alloy prepared by conventional casting. The results of tensile tests indicated that single-crystal and columnar-grained samples had better mechanical properties comparing with the conventional polycrystalline sample. For single-crystal samples, the elongation was 8.7 % and the tensile strength reached to 717MPa, which was 2.2 times as much as that of conventional polycrystalline samples (¦Òb=332MPa). For columnar-grained samples, the tensile strength was 380MPa and the elongation reached 24.2 % , which was 6.5 times higher than that of conventional polycrystalline alloy (¦Ä=3.7 % ). The fatigue limits of single-crystal, columnar-grained and conventional polycrystalline alloys measured by up and down method were 413MPa, 303MPa and 256MPa, respectively. Compared with the conventional polycrystalline sample, the single-crystal and columnar-grained samples had higher fatigue limits, which were 1.6 times and 1.2 times as that of conventional polycrystalline sample. Comparing with the aging state of QBe2.0 with the tensile strength of 1250MPa and fatigue strength of 200MPa, the tensile strengths of single-crystal and columnar-grained Cu-12wt. % Al alloys were about 70 % and 30 % of that of QBe2.0, but the fatigue strengths were twice and 1.5 times of that of QBe2.0, respectively.