| 引用本文: | 刘芳,许光丽,陆郡.超细晶铜力学和阻尼性能及微观结构研究[J].材料科学与工艺,2021,29(2):58-63.DOI:10.11951/j.issn.1005-0299.20190272. |
| LIU Fang,XU Guangli,LU Jun.Researches on mechanical, damping properties and microstructure of ultrafine grained copper[J].Materials Science and Technology,2021,29(2):58-63.DOI:10.11951/j.issn.1005-0299.20190272. |
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| 摘要: |
| 在众多阻尼材料中,金属阻尼材料既能满足高阻尼减振降噪性能,又具有较高的强度,是理想的阻尼材料。为了提高商业纯铜的力学性能,分析晶粒细化程度对纯铜力学性能和阻尼性能的影响,在室温下对商业纯铜棒进行12道次BC路径等通道转角挤压(ECAP) 实验。对挤压后样品进行单轴微拉伸试验和高循环拉伸疲劳试验研究其力学性能；通过动态力学分析仪测量材料的阻尼性能；利用光学显微镜、场发射透射电子显微镜和场发射扫描电子显微镜分析了材料的微观结构和疲劳断口形貌。结果表明:等通道转角挤压后的样品晶粒细化,极限强度、屈服强度和阻尼性能均显著提高,但塑性和疲劳强度随之降低。8道次挤压后,晶粒细化效果达到饱和状态。8道次挤压后纯铜的抗拉强度从297.0 MPa增加到410.7 MPa,屈服强度由276 MPa增加到401.2 MPa；4道次和8道次挤压后纯铜的内耗活化能分别为0.65和1.11 eV。断裂伸长率从18.4%降至14.4%；4道次和8道次挤压后纯铜的疲劳强度分别为109和102 MPa,断裂机制从韧性断裂向脆性断裂转变。 |
| 关键词: 商业纯铜 等通道转角挤压 微观结构 力学性能 阻尼性能 |
| DOI：10.11951/j.issn.1005-0299.20190272 |
| 分类号:TG376.8 |
| 文献标识码:A |
| 基金项目:国家自然科学基金资助项目(NSFC 51601115). |
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| Researches on mechanical, damping properties and microstructure of ultrafine grained copper |
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LIU Fang, XU Guangli, LU Jun
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(School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China) [HJ1.6mm]
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| Abstract: |
| Metal are ideal resistance materials due to both high damping and high strength. In order to improve the mechanical properties of commercial pure cooper (CP-Cu) and study the effect of grain refinement on the mechanical properties and damping properties, CP-Cu was extruded up to 12 passes through BC path at room temperature by equal channel angular pressing (ECAP). The mechanical properties of extruded samples were examined by micro-uniaxial tensile tests and high cycle tensile fatigue tests. Damping properties of materials were characterized by dynamic mechanical analysis (DMA). Microstructure and fracture morphologies were analyzed by optical microscope (OM), transmission electron microscope (TEM) and scanning electron microscopy (SEM). The results indicated that the grain size decreased after ECAP. Ultimate strength, yield strength and damping properties were significantly increased whereas plasticity and fatigue strength were decreased. The grain refining effect reached saturation, and tensile strength increased from 297.0 MPa to 410.7 MPa and yield strength increased from 276 MPa to 401.2 MPa after 8 passes. Internal friction activation energies after 4 passes and 8 passes were 0.65 eV and 1.11 eV, respectively. Elongation decreased from 18.4% to 14.4%. Fatigue strengths after 4 passes and 8 passes were 109 MPa and 102 MPa, respectively. Fracture mechanism evolved from ductile fracture to brittle fracture. |
| Key words: CP-Cu ECAP microstructure mechanical properties damping properties |
