1.1 本试验方法涵盖了使用硝酸蒸汽测定厚度大于0.6μm（25μin.）的金镀层孔隙率的设备和程序，尤其是电触点上使用的电镀层和覆层金属。 1.2 该测试方法旨在显示孔隙度水平是否小于或大于某个值，根据经验，用户认为该值可用于预期应用。 1.3 指南中描述了多种其他孔隙度测试方法 B765型 以及在文献中。 2. , 3. 其他孔隙度测试方法为测试方法 B741型 , B798型 , B799 和 第809页 . 1.4 以国际单位表示的值应视为标准值。括号中给出的值仅供参考。 1.5 本标准并不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熟悉所有危险，包括制造商提供的该产品/材料的适当安全数据表（SDS）中确定的危险，建立适当的安全、健康和环境实践，并在使用前确定监管限制的适用性。 第节给出了具体的预防措施 8. 和 9.4 . 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《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====== 5.1 金涂层通常用于可分离电连接器和其他设备的触点。电沉积是最常用于触点的金的形式，尽管它也被用作覆层金属和触点表面的焊件。金的内在高贵性使其能够抵抗可能干扰可靠接触操作的绝缘氧化膜的形成。 5.2 为了确保金的高贵，涂层中的孔隙率、裂缝和其他缺陷暴露出基底- 金属衬底和底板必须最小或不存在，除非在结构中使用触点以保护表面不受环境影响，或对沉积物进行腐蚀抑制表面处理是可行的。涂层中可容忍的孔隙率水平取决于底板或衬底的环境严重性、接触装置的设计因素（如配合力）、电路参数以及必须保持的接触操作可靠性。此外，当存在时，表面上孔隙的位置很重要。如果孔的数量很少，且位于配合面接触区域之外，则通常可以容忍孔的存在。 5.3 如果能够确定接触表面上的孔的精确位置和数量，则确定接触表面的孔的方法是最合适的。 接触表面通常是弯曲的或不规则的，测试方法应适用于它们。此外，孔隙度测定试验的严重程度可能有所不同。这种测试方法被认为是严格的。 5.4 特定测试所揭示的孔隙率水平与接触行为之间的关系必须由这些测试的用户通过实际经验或判断得出。因此，涂层中没有孔隙可能是某些应用的要求，而临界表面上的一些孔隙可能是另一种应用的要求。此类验收（或合格-不合格）标准应作为需要孔隙度测试的特定产品或零件的产品规范的一部分。 5.5 该测试方法高度敏感，能够检测可能参与基底腐蚀反应的金涂层中的几乎所有孔隙率或其他缺陷。该测试快速、简单、廉价。 此外，它还可用于具有复杂几何形状的触点，如插针-插座触点。然而，在测试之前，最好打开深凹插座以暴露其关键表面。 5.6 该试验方法被认为是破坏性的，因为它通过腐蚀产物污染表面和在孔位置或未电镀区域边界处的涂层底切来揭示孔隙率的存在。暴露在这些试验中的任何部件不得投入使用。 5.7 本试验方法仅用于定量描述孔隙（如每单位面积或每次接触的孔隙数量），其孔隙密度足够低，腐蚀部位可以很好地分离，并且可以很容易地解决。作为一般准则，这可以在孔密度高达约100/cm的情况下实现 2. 或每100个接触。高于该值时，测试可用于孔隙度的定性检测和比较。

1.1 This test method covers equipment and procedures for using nitric acid vapor for determining porosity in gold coatings, greater than 0.6 μm (25 μin.) in thickness, particularly electrodeposits and clad metals used on electrical contacts. 1.2 This test method is designed to show whether the porosity level is less or greater than some value that, by experience, is considered by the user to be acceptable for the intended application. 1.3 A variety of other porosity testing methods are described in Guide B765 and in the literature. 2 , 3 Other porosity test methods are Test Methods B741 , B798 , B799 , and B809 . 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.5 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 become familiar with all hazards including those identified in the appropriate Safety Data Sheet (SDS) for this product/material as provided by the manufacturer, to establish appropriate safety, health, and environmental practices, and determine the applicability of regulatory limitations prior to use. Specific precautions are given in Section 8 and 9.4 . 1.6 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 ====== 5.1 Gold coatings are often specified for the contacts of separable electrical connectors and other devices. Electrodeposits are the form of gold that is most used on contacts, although it is also employed as clad metal and as weldments on the contact surface. The intrinsic nobility of gold enables it to resist the formation of insulating oxide films that could interfere with reliable contact operation. 5.2 In order that the nobility of gold be assured, porosity, cracks, and other defects in the coating that expose base-metal substrates and underplates must be minimal or absent, except in those cases where it is feasible to use the contacts in structures that shield the surface from the environment or where corrosion inhibiting surface treatments for the deposit are employed. The level of porosity in the coating that may be tolerable depends on the severity of the environment to the underplate or substrate, design factors for the contact device like the force with which it is mated, circuit parameters, and the reliability of contact operation that it is necessary to maintain. Also, when present, the location of pores on the surface is important. If the pores are few in number and are outside of the zone of contact of the mating surfaces, their presence can often be tolerated. 5.3 Methods for determining pores on a contact surface are most suitable if they enable their precise location and numbers to be determined. Contact surfaces are often curved or irregular in shape, and testing methods should be suitable for them. In addition, the severity of porosity-determining tests may vary. This test method is regarded as severe. 5.4 The relationship of porosity levels revealed by particular tests to contact behavior must be made by the user of these tests through practical experience or by judgement. Thus, absence of porosity in the coating may be a requirement for some applications, while a few pores on the critical surfaces may be acceptable for another. Such acceptance (or pass-fail) criteria should be part of the product specification for the particular product or part requiring the porosity test. 5.5 This test method is highly sensitive and is capable of detecting virtually all porosity or other defects in gold coatings that could participate in substrate corrosion reactions. The test is rapid, simple, and inexpensive. In addition, it can be used on contacts having complex geometry such as pin-socket contacts. However, it is preferred that deeply recessed sockets be opened to expose their critical surfaces prior to testing. 5.6 This test method is considered destructive in that it reveals the presence of porosity by contaminating the surface with corrosion products and by undercutting the coating at pore sites or at the boundaries of unplated areas. Any parts exposed to these tests shall not be placed in service. 5.7 This test method is intended to be used for quantitative descriptions of porosity (such as number of pores per unit area or per contact) only on coatings that have a pore density sufficiently low that the corrosion sites are well separated and can be readily resolved. As a general guideline this can be achieved for pore densities up to about 100/cm 2 or per 100 contacts. Above this value the tests are useful for the qualitative detection and comparisons of porosity.