ASTM C1425-11

Continuous fiber-reinforced ceramic composites are candidate materials for structural applications requiring high degrees of wear and corrosion resistance, and damage tolerance at high temperatures.

The 1-D and 2-D CFCCs are highly anisotropic and their transthickness tensile and interlaminar shear strength are lower than their in-plane tensile and in-plane shear strength, respectively.

Shear tests provide information on the strength and deformation of materials under shear stresses.

This test method may be used for material development, material comparison, quality assurance, characterization, and design data generation.

For quality control purposes, results derived from standardized shear test specimens may be considered indicative of the response of the material from which they were taken for given primary processing conditions and post-processing heat treatments.

1.1 This test method addresses the compression of a double-notched test specimen to determine interlaminar shear strength of continuous fiber-reinforced ceramic composites (CFCCs) at elevated temperatures. Failure of the test specimen occurs by interlaminar shear between two centrally located notches machined halfway through the thickness of the test specimen and spaced a fixed distance apart on opposing faces (see Fig. 1). Test specimen preparation methods and requirements, testing modes (force or displacement control), testing rates (force rate or displacement rate), data collection, and reporting procedures are addressed.

1.2 This test method is used for testing advanced ceramic or glass matrix composites with continuous fiber reinforcement having a laminated structure such as in unidirectional (1-D) or bidirectional (2-D) fiber architecture (lay-ups of unidirectional plies or stacked fabric). This test method does not address composites with nonlaminated structures, such as (3-D) fiber architecture or discontinuous fiber-reinforced, whisker-reinforced, or particulate-reinforced ceramics.

1.3 Values expressed in this test method are in accordance with the International System of Units (SI) and .

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 and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are noted in 8.1 and 8.2.

FIG. 1 Schematic of Compression of Double-Notched Test Specimen for the Determination of Interlaminar Shear Strength of CFCCs