首页> 外文OA文献 >Microstructure and mechanical properties of aluminium based nanocomposites strengthened with alumina and silicon carbide
【2h】

Microstructure and mechanical properties of aluminium based nanocomposites strengthened with alumina and silicon carbide

机译:氧化铝和碳化硅增强铝基纳米复合材料的组织和力学性能

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务,本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文,但由于OA文献来源多样且变更频繁,仍可能出现获取不到、文献不完整或与标题不符等情况,如果获取不到我们将提供退款服务。请知悉。

摘要

Al-Al₂O₃ and Al-4wt%Cu-SiC metal matrix nanocomposites were studied because these materials have a potential for offering good ductility, high strength, and high electrical and/or thermal conductivity, which make them ideal for engineering applications such as aerospace and automobile components. In order to achieve these goals the reinforcement phase needs to be in a particulate form, and the size of the particles needs to be small.Samples of aluminium based nanocomposites were produced with different volume fractions, ranging from 2.5-10 vol.% of alumina (Al₂O₃) and silicon carbide (SiC) nanoparticles. High energy mechanical milling (HEMM) with various milling times ranging from 6-12 hours was used to produce these samples. Optical microscopy, XRD, SEM, TEM and microindentation were used to characterize the milled powder and bulk samples. Bulk solid Al-(2.5-10) vol. % Al₂O₃ and Al-4wt%Cu-(2.5-10) vol. %SiC nanocomposites samples were produced using different powder consolidation techniques such as powder compact forging and powder compact extrusion.The microstructure of the composite powder/balls/granules produced was studied in details to understand the morphology, macrostructure and microstructural evolution during the HEMM and with changing volume percent of the reinforcements in the matrix. The nano SiC and Al₂O₃ were imbedded into the aluminium matrix due to the high forces and strains affecting particle surfaces during milling and the very small size of the reinforcement relative to the size of the Al particles. The average microhardness was increased with increasing volume fraction of reinforcement within the matrix. HEMM was used to fabricate Ultra-Fine Grained (UFG) and nanostructured Al- (2.5-10) vol. %Al₂O₃ composites with a dispersion of nano alumina within the matrix and Al-4wt%Cu- (2.5-10) vol%SiC with two different sizes of SiC in the micro and nano ranges.A UFG structure in the Al and Al-(2.5-10)vol.% Al₂O₃ nanocomposites can be synthesized by a combination of high energy mechanical milling and severe plastic deformation used to consolidate the powder compacts into nearly fully dense forged discs and extruded bars. No significant microscopic yielding was found in the Al-2.5 and 10 vol. %Al₂O₃ composites produced by powder compact forging. However, Al-5vol. % Al₂O₃ showed plastic yielding of 8%, and the best fracture strength of 343 MPa. No significant microscopic yielding was noticed for the Al- 10 vol. %Al₂O₃ composite produced by powder compact extrusion. Al-2.5vol. % Al₂O₃ showed plastic yielding of ~1% with the highest tensile strength of 364 MPa while Al-5vol. % Al₂O₃ showed plastic yielding of 8% with a yield strength of 318 MPa.The average microhardness of the extruded bars for Al-4wt%Cu-(2.5-10)vol.% SiC increased from 104 HV to 205 HV with increasing the volume fraction of SiC nanoparticles from 2.5 to 10%. The ultimate tensile strength increased from 168 MPa to 400 MPa with increasing volume fraction of SiC nanoparticles from 2.5 to 5% while the ductility dropped from 6.8% to 1.2 %. The fracture strength of the Al-4wt%Cu-micro-SiC was increased from 225 MPa for Al-4wt%Cu-2.5vol. %SiC to 412 MPa for Al-4wt%Cu-10vol. % SiC. The Al-4wt%Cu-2.5vol. %SiC forged disc did not show any macroscopic plastic yielding, while the Al-4wt%Cu-(7.5 and 10)vol. %SiC forged disk showed macroscopic plastic yielding with a small plastic strain to fracture (~1%).
机译:对Al-Al 2 O 3和Al-4wt%Cu-SiC金属基纳米复合材料进行了研究,因为这些材料具有提供良好延展性,高强度以及高电导率和/或导热率的潜力,这使其成为航空航天和航空航天等工程应用的理想选择汽车零部件。为了实现这些目标,增强相需要呈颗粒状,并且颗粒的尺寸必须较小。制备了铝基纳米复合材料的样品,其体积分数为氧化铝的2.5-10%(体积)。 (Al 2 O 3)和碳化硅(SiC)纳米粒子。使用高能机械研磨(HEMM)和6-12小时的各种研磨时间来生产这些样品。使用光学显微镜,XRD,SEM,TEM和显微压痕来表征研磨后的粉末和块状样品。散装固体Al-(2.5-10)vol。 %Al 2 O 3和Al-4wt%Cu-(2.5-10)体积。用不同的粉末固结技术(例如粉末压实锻造和粉末压实挤压)生产%SiC纳米复合材料样品。详细研究了所生产的复合粉末/球/颗粒的微观结构,以了解HEMM期间的形貌,宏观结构和微观结构演变。改变基体中增强材料的体积百分比。由于在研磨过程中影响颗粒表面的高力和应变以及相对于Al颗粒尺寸很小的增强材料尺寸,纳米SiC和Al 2 O 3被嵌入铝基质中。平均显微硬度随基质内增强材料体积分数的增加而增加。 HEMM用于制造超细晶粒(UFG)和纳米结构的Al-(2.5-10)体积。在基体中分散有纳米氧化铝的%Al 2 O 3复合材料和在微米和纳米范围内具有两种不同尺寸的SiC的Al-4wt%Cu-(2.5-10)vol%SiC.Al和Al-( 2.5-10%(体积)的Al 2 O 3纳米复合材料可以通过高能机械研磨和严重的塑性变形相结合来合成,这些复合物用于将粉末压块固结成几乎完全致密的锻造圆盘和挤压棒。在Al-2.5和10vol中没有发现明显的微观屈服。通过粉末压实锻造生产的%Al 2 O 3复合材料。但是,Al-5vol。 Al 2 O 3%表明塑性屈服为8%,最佳断裂强度为343MPa。对于Al-10vol,没有观察到明显的微观屈服。通过粉末压坯挤出生产的%Al 2 O 3复合材料。铝2.5卷%Al 2 O 3表示塑性屈服率为〜1%,最高拉伸强度为364MPa,而Al-5vol。 %Al 2 O 3显示出8%的塑性屈服,屈服强度为318 MPa。随着体积的增加,Al-4wt%Cu-(2.5-10)vol。%SiC的挤压棒的平均显微硬度从104 HV增加到205 HV。 SiC纳米颗粒的比例从2.5%到10%。随着SiC纳米颗粒的体积分数从2.5增加到5%,极限拉伸强度从168 MPa增加到400 MPa,而延展性从6.8%下降到1.2%。对于Al-4wt%Cu-2.5vol,Al-4wt%Cu-micro-SiC的断裂强度从225 MPa增加。对于Al-4wt%Cu-10vol,SiC含量可达412 MPa。 SiC含量Al-4wt%Cu-2.5vol。 %SiC锻造盘未显示任何宏观塑性屈服,而Al-4wt%Cu-(7.5和10)vol。 %SiC锻造盘表现出宏观的塑性屈服,断裂塑性应变小(〜1%)。

著录项

  • 作者

    Gazawi Amro Abdul-Karim;

  • 作者单位
  • 年度 2014
  • 总页数
  • 原文格式 PDF
  • 正文语种 {"code":"en","name":"English","id":9}
  • 中图分类

相似文献

  • 外文文献
  • 中文文献
  • 专利

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号