• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Materials Research >In-situ study of microscale fracture of diffusion aluminide bond coats: Effect of platinum
【24h】

In-situ study of microscale fracture of diffusion aluminide bond coats: Effect of platinum

机译：扩散铝化物粘结涂层微观断裂的原位研究：铂的作用

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The influence of Pt layer thickness on the fracture behavior of PtNiAl bond coats was studied in situ using clamped micro-beam bend tests inside a scanning electron microscope (SEM). Clamped beam bending is a fairly well established micro-scale fracture test geometry that has been previously used in determination of fracture toughness of Si and PtNiAl bond coats. The increasing amount of Pt in the bond coat matrix was accompanied by several other microstructural changes such as an increase in the volume fraction of α-Cr precipitate particles in the coating as well as a marginal decrease in the grain size of the matrix. In addition, Pt alters the defect chemistry of the B2-NiAl structure, directly affecting its elastic properties. A strong correlation was found between the fracture toughness and the initial Pt layer thickness associated with the bond coat. As the Pt layer thickness was increased from 0 to 5 μm, resulting in increasing Pt concentration from 0 to 14.2 at.% in the B2-NiAl matrix and changing α-Cr precipitate fraction, the initiation fracture toughness (K_(IC)) was seen to rise from 6.4 to 8.5 MPa·m~(1/2). R-curve behavior was observed in these coatings, with K_(IC) doubling for a crack propagation length of 2.5 μm. The reasons for the toughening are analyzed to be a combination of material's microstructure (crack kinking and bridging due to the precipitates) as well as size effects, as the crack approaches closer to the free surface in a micro-scale sample.
机译：使用扫描电子显微镜（SEM）内的夹紧微束弯曲试验原位研究了Pt层厚度对PtNiAl粘结层断裂行为的影响。夹紧梁弯曲是一种相当完善的微观断裂试验几何形状，以前已用于确定Si和PtNiAl粘结涂层的断裂韧性。粘结涂层基体中Pt的增加伴随着其他一些微观结构的变化，例如涂层中α-Cr沉淀颗粒的体积分数的增加以及基体晶粒尺寸的减小。另外，Pt改变了B2-NiAl结构的缺陷化学，直接影响其弹性。发现断裂韧性和与粘结涂层相关的初始Pt层厚度之间有很强的相关性。随着Pt层厚度从0增加到5μm，导致B2-NiAl基体中Pt浓度从0增加到14.2 at。％，并且改变了α-Cr沉淀分数，初始断裂韧性（K_（IC））为从6.4上升到8.5 MPa·m〜（1/2）。在这些涂层中观察到R曲线行为，其中K_（IC）倍增，裂纹扩展长度为2.5μm。分析了韧化的原因是由于材料的微观结构（由于沉淀而导致的裂纹扭结和桥接）以及尺寸效应的组合，因为裂纹在微型样品中接近自由表面。

著录项

  • 来源
    《Journal of Materials Research》 |2015年第21期|3343-3353|共11页
  • 作者

    Balila Nagamani Jaya; Sanjit Bhowmick; S.A. Syed Asif; Vikram Jayaram;

  • 作者单位

    Department of Materials Engineering, Indian Institute of Science, Bangalore, Kamataka 560012, India ,Max Planck Institute for Iron Research, Max Planck Strasse-1, Duesseldorf 40237, Germany;

    Hysitron Inc., Minneapolis, Minnesota 55344, USA;

    Hysitron Inc., Minneapolis, Minnesota 55344, USA;

    Department of Materials Engineering, Indian Institute of Science, Bangalore, Kamataka 560012, India;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

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