5.1 The test is used to determine the oxidative resistances of carbon fibers as a means of selecting the most stable fibers for incorporation in high-temperature fiber-reinforced composite systems. It can be used for quality control, material specification, and for research and development of improved carbon fibers. Factors that influence the oxidative resistance and should be reported are fiber identification, carbon fiber precursor type, fiber modulus, and any information on impurities, particularly metals. Also note that the presence of finish on the fiber can affect the oxidative resistance, and thus, alternative specimen preparations that enable the evaluation of finish effects are included.

1.1 This test method covers the apparatus and procedure for the determination of the weight loss of carbon fibers, exposed to ambient hot air, as a means of characterizing their oxidative resistance.

1.2 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.2.1 Within the text, the inch-pound units are shown in brackets.

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. For specific hazard information, see Section 8.

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.