1.1 这些试验方法涵盖了对根据指南制备的热喷涂涂层（TSC）金相试样进行孔隙率评级的程序 E1920 通过与标准图像直接比较，并使用自动图像分析设备。 1.2 这些试验方法仅涉及推荐的测量方法，其中的任何内容都不应被解释为定义或确定孔隙度任何测量值的可接受限度。 1.3 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1. 4. 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 由于喷涂颗粒之间缺乏融合或喷涂过程中产生的气体膨胀，TSC容易形成孔隙。为了监测可变喷涂参数的影响以及涂层对其预期用途的适用性，确定孔隙率的面积百分比非常重要。根据应用情况，这些孔隙中的一些或任何一个都是可以容忍的。 4.2 这些试验方法包括测定TSC的面积百分比孔隙度。方法A是一种手动直接比较方法，利用了 无花果。1- 7. 描述了TSC中孔隙度的典型分布。方法B是一种自动化技术，需要使用计算机图像分析仪。 图1 —  0.5 % 多孔性 图2 —  1 % 多孔性 图3 —  2 % 多孔性 图4 —  5 % 多孔性 图5 —  8 % 多孔性 图6 —  10 % 多孔性 图7 —  15 % 多孔性 4.3 这些方法仅基于金相抛光横截面的光反射率来量化面积百分比孔隙度。请参阅指南 E1920 推荐的金相制备程序。 4.4 使用这些测试方法的人员必须熟悉TSC的视觉特征，并能够确定固有孔隙度和氧化物之间的差异。 个人必须了解切片和样本制备过程中可能产生的伪影类型，例如拔出和涂抹，以便仅报告正确制备的样本的结果。适当制备的样本示例如所示 无花果。8- 10 . 如果对试样制备的完整性有疑问，建议使用其他方法来确认微观结构特征。这可能包括能量色散光谱（EDS）、波长色散光谱（WDS）或涂层的低温断裂，然后用扫描电子显微镜（SEM）分析断裂表面。 图8 镍/铝TSC-500X 注1: V=空隙，O=氧化物，L=线性剥离 图9 蒙乃尔TSC-200X 注1: V=空隙，G=嵌入砂砾，L=线性分离 图10 合金625 TSC-200X 注1: V=空隙，O=氧化物，G=嵌入砂砾

1.1 These test methods cover procedures to perform porosity ratings on metallographic specimens of thermal sprayed coatings (TSCs) prepared in accordance with Guide E1920 by direct comparison to standard images and via the use of automatic image analysis equipment. 1.2 These test methods deal only with recommended measuring methods and nothing in them should be construed as defining or establishing limits of acceptability for any measured value of porosity. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 TSCs are susceptible to the formation of porosity due to a lack of fusion between sprayed particles or the expansion of gases generated during the spraying process. The determination of area percent porosity is important in order to monitor the effect of variable spray parameters and the suitability of a coating for its intended purpose. Depending on application, some or none of this porosity may be tolerable. 4.2 These test methods cover the determination of the area percentage porosity of TSCs. Method A is a manual, direct comparison method utilizing the seven standard images in Figs. 1- 7 which depict typical distributions of porosity in TSCs. Method B is an automated technique requiring the use of a computerized image analyzer. FIG. 1 —  0.5 % Porosity FIG. 2 —  1.0 % Porosity FIG. 3 —  2.0 % Porosity FIG. 4 —  5.0 % Porosity FIG. 5 —  8.0 % Porosity FIG. 6 —  10.0 % Porosity FIG. 7 —  15.0 % Porosity 4.3 These methods quantify area percent porosity only on the basis of light reflectivity from a metallographically polished cross section. See Guide E1920 for recommended metallographic preparation procedures. 4.4 The person using these test methods must be familiar with the visual features of TSCs and be able to determine differences between inherent porosity and oxides. The individual must be aware of the possible types of artifacts that may be created during sectioning and specimen preparation, for example, pullouts and smearing, so that results are reported only on properly prepared specimens. Examples of properly prepared specimens are shown in Figs. 8- 10 . If there are doubts as to the integrity of the specimen preparation it is suggested that other means be used to confirm microstructural features. This may include energy dispersive spectroscopy (EDS), wavelength dispersive spectroscopy (WDS) or cryogenic fracture of the coating followed by analysis of the fractured surfaces with a scanning electron microscope (SEM). FIG. 8 Ni/Al TSC—500X Note 1: V = void, O = oxide, L = linear detachment FIG. 9 Monel TSC—200X Note 1: V = void, G = embedded grit, L = linear detachment FIG. 10 Alloy 625 TSC—200X Note 1: V = void, O = oxide, G = embedded grit