1.1 本试验方法包括测定硬质合金的断裂韧性( K IcSR )通过测试开槽短杆或短棒试样。 1.2 以国际单位制表示的数值应视为标准值。括号中给出的值仅供参考。 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====== 5.1 财产 K IcSR 通过本试验方法测定的结果被认为表征了硬质合金在严重拉伸约束下出现尖锐裂纹时在中性环境中的抗断裂性能，从而使裂纹前缘附近的应力状态接近三张平面应变，与约束方向上的裂纹尺寸和试样尺寸相比，裂纹尖端塑性区较小。A. K IcSR 该值被认为代表断裂韧性的下限值。当预期上述高约束条件时，该值可用于估计失效应力和缺陷尺寸之间的关系。关于在线弹性断裂力学方面开发本试验方法的基础的背景信息，可在参考文献中找到 ( 1- 7. ) . 3. 5.2 本试验方法可用于以下目的: 5.2.1 在对使用性能有重要影响的定量方面，确定制造变量对新材料或现有材料断裂韧性的影响，以及 5.2.2 确定材料对特定应用的适用性，其中规定了应力条件，并且可以确定最大缺陷尺寸。

1.1 This test method covers the determination of the fracture toughness of cemented carbides ( K IcSR ) by testing slotted short rod or short bar specimens. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 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 ====== 5.1 The property K IcSR determined by this test method is believed to characterize the resistance of a cemented carbide to fracture in a neutral environment in the presence of a sharp crack under severe tensile constraint, such that the state of stress near the crack front approaches tri-tensile plane strain, and the crack-tip plastic region is small compared with the crack size and specimen dimensions in the constraint direction. A K IcSR value is believed to represent a lower limiting value of fracture toughness. This value may be used to estimate the relation between failure stress and defect size when the conditions of high constraint described above would be expected. Background information concerning the basis for development of this test method in terms of linear elastic fracture mechanics may be found in Refs ( 1- 7 ) . 3 5.2 This test method can serve the following purposes: 5.2.1 To establish, in quantitative terms significant to service performance, the effects of fabrication variables on the fracture toughness of new or existing materials, and 5.2.2 To establish the suitability of a material for a specific application for which the stress conditions are prescribed and for which maximum flaw sizes can be established with confidence.