Description

1.1 This test method covers the determination of fracture toughness (KIc) of metallic materials under predominantly linear-elastic, plane-strain conditions using fatigue precracked specimens having a thickness of 1.6 mm (0.063 in.) or greater subjected to slowly, or in special (elective) cases rapidly, increasing crack-displacement force. Details of test apparatus, specimen configuration, and experimental procedure are given in the Annexes.

Note 1

Plane-strain fracture toughness tests of thinner materials that are sufficiently brittle (see ) can be made using other types of specimens (). There is no standard test method for such thin materials.

1.2 This test method is divided into two parts. The first part gives general recommendations and requirements for KIc testing. The second part consists of Annexes that give specific information on displacement gage and loading fixture design, special requirements for individual specimen configurations, and detailed procedures for fatigue precracking. Additional annexes are provided that give specific procedures for beryllium and rapid-force testing.

1.3 General information and requirements common to all specimen configurations:

SectionReferenced DocumentsTerminologyStress-Intensity FactorPlane-Strain Fracture ToughnessCrack Plane OrientationSummary of Test MethodSignificance and UseSignificancePrecautionsPractical ApplicationsApparatus (see also )Tension MachineFatigue MachineLoading FixturesDisplacement Gage, MeasurementSpecimen Size, Configurations, and Preparation (see also )Specimen Size EstimatesStandard and Alternative Specimen ConfigurationsFatigue Crack Starter NotchesFatigue Precracking (see also )Crack Extension Beyond Starter NotchGeneral ProcedureSpecimen MeasurementsThicknessWidthCrack SizeCrack Plane AngleSpecimen TestingLoading RateTest RecordCalculation and Interpretation of ResultsTest Record AnalysisPm ax/PQ Validity RequirementSpecimen Size Validity RequirementsReportingPrecision and Bias

1.4 Specific requirements related to test apparatus:

Double-Cantilever Displacement GageTesting FixturesBend Specimen Loading FixtureAnnex Compact Specimen Loading ClevisAnnex

1.5 Specific requirements related to individual specimen configurations:

Bend Specimen SE(B)Compact Specimen C(T)Disk-Shaped Compact Specimen DC(T)Arc-Shaped Tension Specimen A(T)Arc-Shaped Bend Specimen A(B)

1.6 Specific requirements related to special test procedures:

Fatigue Precracking KIc SpecimensHot-Pressed Beryllium TestingRapid-Force Testing

1.7 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.8 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 and health practices and determine the applicability of regulatory limitations prior to use.