1.1 这些测试方法涵盖了塑料对“标准化”的抵抗力的测定（见 附注1 ）安装在“标准化”机器上的摆锤，用一次摆锤破碎标准样品（见 附注2 ).这些试验方法的标准试验要求用铣削缺口制作试样（见 附注3 ).在测试方法A和C中，缺口产生应力集中，增加了脆性断裂而不是延性断裂的可能性。结果以每单位试样宽度或每单位切口下横截面积吸收的能量来报告。（见 附注4 .) 附注1: 具有摆式锤的机器已经“标准化”，因为它们必须符合某些要求，包括固定的锤下落高度，这导致锤在撞击时刻的基本固定的速度。然而，建议将不同初始能量（通过改变其有效重量产生）的锤子用于不同抗冲击性的样品。此外，允许设备的制造商使用不同长度和结构的摆锤，这可能导致摆锤刚度的差异。（见第节 5 .)请注意，机器设计中可能存在其他差异。样品是“标准化的”，因为它们需要具有一个固定的长度、一个固定的深度和一个特定的铣削凹口设计。样品的宽度允许在限值之间变化。 附注2: 使用利用测力传感器记录冲击力并因此记录冲击能量的摆产生的结果可能不等同于使用测量冲击后摆中剩余能量的手动或数字编码测试仪产生的结果。附注3: 悬臂梁试样中的缺口用于集中应力，最小化塑性变形，并将断裂导向试样缺口后面的部分。因此减少了能量到断裂的分散。然而，由于塑料的弹性和粘弹性性质的差异，对给定缺口的响应因材料而异。 附注4: 在解释这些标准测试方法的结果时必须谨慎。以下测试参数可能会显著影响测试结果: 制造方法，包括但不限于加工 技术、成型条件、模具设计和热 治疗； 开槽方法； 开槽工具的速度； 开槽装置的设计； 缺口的质量； 开槽和测试之间的时间； 试样厚度， 缺口下的试样宽度，以及 环境调节。 1.2 测试方法按以下顺序显示: 章节 试验方法A-悬臂梁试验 6 到 11 试验方法C-小于27 J/m(0.5 ft·lbf/in.)材料的悬臂梁试验 12 到 17 1.3 以SI单位表示的值将被视为标准值。括号中给出的值仅供参考。 1.4 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践并确定法规限制的适用性。 附注5: 这些试验方法仅在标题方面类似于ISO 180:1993。内容明显不同。1.5 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》中确立的国际公认的标准化原则制定的。 ======意义和用途====== 5.1 在进行这些测试方法之前，应参考被测材料的质量标准。材料质量标准中涵盖的任何试样制备、调节、尺寸和试验参数应优先于这些试验方法中提及的参数。如果没有材料规格，则适用默认条件。 5.2 摆锤冲击试验表示在试样安装、开槽和摆锤速度的规定参数下，破碎规定尺寸的标准试样的能量-撞击时。 5.3 试样断裂过程中摆锤损失的能量为以下各项之和: 5.3.1 引发试样断裂的能量； 5.3.2 使断裂在试样上传播的能量； 5.3.3 投掷破碎样品的自由端（或多个自由端）的能量（“投掷校正”）； 5.3.4 弯曲试样的能量； 5.3.5 在摆臂中产生振动的能量； 5.3.6 使机架或底座产生振动或水平运动的能量； 5.3.7 克服摆轴承和指示机构中的摩擦以及克服风阻（摆空气阻力）的能量； 5.3.8 使试样在冲击线处凹陷或塑性变形的能量；和 5.3.9 克服由撞针（或钟摆的其他部分）在弯曲样品表面上的摩擦引起的摩擦的能量。5.4 对于断裂扩展能量与断裂起始能量相比较小的相对脆性材料，为了所有实际目的，所示吸收的冲击能量是以下因素的总和 5.3.1 和 5.3.3 折腾校正（见 5.3.3 ）可能代表测试相对致密和脆性材料时吸收的总能量的非常大的部分。试验方法C应用于Izod抗冲击性小于27 J/m（0.5 ft·lbf/in.）的材料。（见 附录X4 对于可选单元。）在试验方法C中获得的抛掷修正仅是抛掷误差的近似值，因为在试样的重新抛掷过程中，旋转速度和直线速度可能与初始抛掷时不同，并且因为试样中储存的应力可能在试样断裂过程中作为动能释放。5.5 对于坚韧、延展性、纤维填充或布层压材料，断裂扩展能（见 5.3.2 ）与断裂起始能量相比可能很大（见 5.3.1 ).在测试这些材料时，因素（见 5.3.2 , 5.3.5 ，和 5.3.9 ）可能变得相当重要，即使当样品被精确加工和定位并且机器处于良好状态并具有足够的容量时。（见 附注7 .）弯曲（见 5.3.4 ）和压痕损失（见 5.3.8 ）在测试软材料时可能是可察觉的。 附注7: 尽管机器的框架和底座应具有足够的刚性和质量，以在不运动或过度振动的情况下处理坚韧样品的能量，但设计必须确保撞击中心位于撞击中心。当与脆性样品一起使用时，将撞针精确地定位在撞击中心可以减少摆臂的振动。然而，即使撞针正确定位，由于摆臂振动（其量随摆的设计而变化）也会在坚韧的样品中发生一些损失。 5.6 在设计良好、具有足够刚度和质量的机器中，由于以下因素造成的损失 5.3.6 和 5.3.7 应该很小。振动损失（见 5.3.6 ）当在质量不足的机器中测试坚韧材料的宽样品时，没有牢固地固定在沉重的底座上。 5.7 对于某些材料，可以发现试样的临界宽度，低于该临界宽度，试样将表现为延展性，如缺口后面区域中相当大的拉伸或颈缩以及相对高能量吸收所证明的，高于该临界宽度，试样将表现为脆性，如很少或没有拉伸或颈缩以及相对低的-能量吸收。由于这些方法允许试样宽度的变化，并且对于许多材料来说，宽度决定了是否会发生脆性、低能量断裂或延展性、高能量断裂，因此有必要在涵盖该材料的说明书中说明宽度，并且宽度与抗冲击性一起报告。鉴于前述，不应在来自宽度相差超过几密耳的样品的数据之间进行比较。 5.8 每个试样的失效类型应记录为下列四个类别之一: C= 完全断裂 -试样分离成两个或更多个碎片的断裂。 H= 铰链断裂 -不完全断裂，使得当样品的另一部分被竖直保持(小于90°夹角)时，样品的一部分不能支撑其自身高于水平面。P= 部分断裂 -不符合铰链断裂的定义但已断裂凹口的顶点与相对侧之间的距离的至少90%的不完全断裂。 NB= 不间断 -不完全断裂，其中断裂延伸小于缺口顶点与相对侧之间距离的90%。 对于坚韧的材料，钟摆可能没有必要的能量来完成极端纤维的断裂和折断的一个或多个碎片。从“非破损”样本获得的结果应视为偏离标准，不应作为标准结果报告。对于经历本规范试验方法中定义的不同类型失效的任何两种材料，不能直接比较其抗冲击性。报告的平均值同样必须来自单个失效类别中包含的样本。该字母代码应在报告的影响后缀，识别与报告值相关的故障类型。如果样品材料观察到一种以上类型的失效，则报告将指示每种失效类型的平均抗冲击性，后面是以这种方式失效的样品的百分比，并以字母代码为后缀。 5.9 冲击方法的价值主要在于质量控制和材料规格领域。如果假定为相同材料的两组样品显示出显著不同的能量吸收、断裂类型、临界宽度或临界温度，则可以假设它们由不同材料制成或暴露于不同的加工或调节环境。一种材料在这些测试条件下表现出两倍于另一种材料的能量吸收这一事实并不表明在另一组测试条件下将存在同样的关系。在不同的测试条件下，韧性的顺序甚至可以颠倒。 附注8: 手动和数字冲击测试仪之间存在记录的差异，主要是热固性材料，包括酚醛树脂，其冲击值小于54 J/m（1 ft-lb/in.）。比较在手动和数字冲击测试仪上测试的相同材料的数据，可以显示来自数字测试仪的数据显著低于来自手动测试仪的数据。在这种情况下，可能需要进行相关性研究，以正确定义工具之间的真实关系。

1.1 These test methods cover the determination of the resistance of plastics to “standardized” (see Note 1 ) pendulum-type hammers, mounted in “standardized” machines, in breaking standard specimens with one pendulum swing (see Note 2 ). The standard tests for these test methods require specimens made with a milled notch (see Note 3 ). In Test Methods A and C, the notch produces a stress concentration that increases the probability of a brittle, rather than a ductile, fracture. Results are reported in terms of energy absorbed per unit of specimen width or per unit of cross-sectional area under the notch. (See Note 4 .) Note 1: The machines with their pendulum-type hammers have been “standardized” in that they must comply with certain requirements, including a fixed height of hammer fall that results in a substantially fixed velocity of the hammer at the moment of impact. However, hammers of different initial energies (produced by varying their effective weights) are recommended for use with specimens of different impact resistance. Moreover, manufacturers of the equipment are permitted to use different lengths and constructions of pendulums with possible differences in pendulum rigidities resulting. (See Section 5 .) Be aware that other differences in machine design may exist. The specimens are “standardized” in that they are required to have one fixed length, one fixed depth, and one particular design of milled notch. The width of the specimens is permitted to vary between limits. Note 2: Results generated using pendulums that utilize a load cell to record the impact force and thus impact energy, may not be equivalent to results that are generated using manually or digitally encoded testers that measure the energy remaining in the pendulum after impact. Note 3: The notch in the Izod specimen serves to concentrate the stress, minimize plastic deformation, and direct the fracture to the part of the specimen behind the notch. Scatter in energy-to-break is thus reduced. However, because of differences in the elastic and viscoelastic properties of plastics, response to a given notch varies among materials. Note 4: Caution must be exercised in interpreting the results of these standard test methods. The following testing parameters may affect test results significantly: Method of fabrication, including but not limited to processing technology, molding conditions, mold design, and thermal treatments; Method of notching; Speed of notching tool; Design of notching apparatus; Quality of the notch; Time between notching and test; Test specimen thickness, Test specimen width under notch, and Environmental conditioning. 1.2 The test methods appear in the following order: Sections Test Method A—Cantilever Beam Test 6 to 11 Test Method C—Cantilever Beam Test for Materials of Less than 27 J/m (0.5 ft·lbf/in.) 12 to 17 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.4 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. Note 5: These test methods resemble ISO 180:1993 in regard to title only. The contents are significantly different. 1.5 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 Before proceeding with these test methods, reference should be made to the specification of the material being tested. Any test specimen preparation, conditioning, dimensions, and testing parameters covered in the materials specification shall take precedence over those mentioned in these test methods. If there is no material specification, then the default conditions apply. 5.2 The pendulum impact test indicates the energy to break standard test specimens of specified size under stipulated parameters of specimen mounting, notching, and pendulum velocity-at-impact. 5.3 The energy lost by the pendulum during the breakage of the specimen is the sum of the following: 5.3.1 Energy to initiate fracture of the specimen; 5.3.2 Energy to propagate the fracture across the specimen; 5.3.3 Energy to throw the free end (or ends) of the broken specimen (“toss correction”); 5.3.4 Energy to bend the specimen; 5.3.5 Energy to produce vibration in the pendulum arm; 5.3.6 Energy to produce vibration or horizontal movement of the machine frame or base; 5.3.7 Energy to overcome friction in the pendulum bearing and in the indicating mechanism, and to overcome windage (pendulum air drag); 5.3.8 Energy to indent or deform plastically the specimen at the line of impact; and 5.3.9 Energy to overcome the friction caused by the rubbing of the striker (or other part of the pendulum) over the face of the bent specimen. 5.4 For relatively brittle materials, for which fracture propagation energy is small in comparison with the fracture initiation energy, the indicated impact energy absorbed is, for all practical purposes, the sum of factors 5.3.1 and 5.3.3 . The toss correction (see 5.3.3 ) may represent a very large fraction of the total energy absorbed when testing relatively dense and brittle materials. Test Method C shall be used for materials that have an Izod impact resistance of less than 27 J/m (0.5 ft·lbf/in.). (See Appendix X4 for optional units.) The toss correction obtained in Test Method C is only an approximation of the toss error, since the rotational and rectilinear velocities may not be the same during the re-toss of the specimen as for the original toss, and because stored stresses in the specimen may have been released as kinetic energy during the specimen fracture. 5.5 For tough, ductile, fiber filled, or cloth-laminated materials, the fracture propagation energy (see 5.3.2 ) may be large compared to the fracture initiation energy (see 5.3.1 ). When testing these materials, factors (see 5.3.2 , 5.3.5 , and 5.3.9 ) can become quite significant, even when the specimen is accurately machined and positioned and the machine is in good condition with adequate capacity. (See Note 7 .) Bending (see 5.3.4 ) and indentation losses (see 5.3.8 ) may be appreciable when testing soft materials. Note 7: Although the frame and base of the machine should be sufficiently rigid and massive to handle the energies of tough specimens without motion or excessive vibration, the design must ensure that the center of percussion be at the center of strike. Locating the striker precisely at the center of percussion reduces vibration of the pendulum arm when used with brittle specimens. However, some losses due to pendulum arm vibration, the amount varying with the design of the pendulum, will occur with tough specimens, even when the striker is properly positioned. 5.6 In a well-designed machine of sufficient rigidity and mass, the losses due to factors 5.3.6 and 5.3.7 should be very small. Vibrational losses (see 5.3.6 ) can be quite large when wide specimens of tough materials are tested in machines of insufficient mass, not securely fastened to a heavy base. 5.7 With some materials, a critical width of specimen may be found below which specimens will appear ductile, as evidenced by considerable drawing or necking down in the region behind the notch and by a relatively high-energy absorption, and above which they will appear brittle as evidenced by little or no drawing down or necking and by a relatively low-energy absorption. Since these methods permit a variation in the width of the specimens, and since the width dictates, for many materials, whether a brittle, low-energy break or a ductile, high energy break will occur, it is necessary that the width be stated in the specification covering that material and that the width be reported along with the impact resistance. In view of the preceding, one should not make comparisons between data from specimens having widths that differ by more than a few mils. 5.8 The type of failure for each specimen shall be recorded as one of the four categories listed as follows: C = Complete Break —A break where the specimen separates into two or more pieces. H = Hinge Break —An incomplete break, such that one part of the specimen cannot support itself above the horizontal when the other part is held vertically (less than 90° included angle). P = Partial Break —An incomplete break that does not meet the definition for a hinge break but has fractured at least 90 % of the distance between the vertex of the notch and the opposite side. NB = Non-Break —An incomplete break where the fracture extends less than 90 % of the distance between the vertex of the notch and the opposite side. For tough materials, the pendulum may not have the energy necessary to complete the breaking of the extreme fibers and toss the broken piece or pieces. Results obtained from “non-break” specimens shall be considered a departure from standard and shall not be reported as a standard result. Impact resistance cannot be directly compared for any two materials that experience different types of failure as defined in the test method by this code. Averages reported must likewise be derived from specimens contained within a single failure category. This letter code shall suffix the reported impact identifying the types of failure associated with the reported value. If more than one type of failure is observed for a sample material, then the report will indicate the average impact resistance for each type of failure, followed by the percent of the specimens failing in that manner and suffixed by the letter code. 5.9 The value of the impact methods lies mainly in the areas of quality control and materials specification. If two groups of specimens of supposedly the same material show significantly different energy absorptions, types of breaks, critical widths, or critical temperatures, it may be assumed that they were made of different materials or were exposed to different processing or conditioning environments. The fact that a material shows twice the energy absorption of another under these conditions of test does not indicate that this same relationship will exist under another set of test conditions. The order of toughness may even be reversed under different testing conditions. Note 8: A documented discrepancy exists between manual and digital impact testers, primarily with thermoset materials, including phenolics, having an impact value of less than 54 J/m (1 ft-lb/in.). Comparing data on the same material, tested on both manual and digital impact testers, may show the data from the digital tester to be significantly lower than data from a manual tester. In such cases a correlation study may be necessary to properly define the true relationship between the instruments.