Standard Practice for Measurement of Ultrasonic Attenuation Coefficients of Advanced Ceramics by Pulse-Echo Contact Technique

Importancia y uso:

5.1 This practice is useful for characterizing material microstructure or measuring variations in microstructure that occur because of material processing conditions and thermal, mechanical, or chemical exposure (3). When applied to monolithic or composite ceramics, the procedure should reveal microstructural gradients due to density, porosity, and grain variations. This practice may also be applied to polycrystalline metals to assess variations in grain size, porosity, and multiphase constituents.

5.2 This practice is useful for measuring and comparing microstructural variations among different samples of the same material or for sensing and measuring subtle microstructural variations within a given sample.

5.3 This practice is useful for mapping variations in the attenuation coefficient and the attenuation spectrum as they pertain to variations in the microstructure and associated properties of monolithic ceramics, ceramic composites and metals.

5.4 This practice is useful for establishing a reference database for comparing materials and for calibrating ultrasonic attenuation measurement equipment.

5.5 This practice is not recommended for highly attenuating monolithics or composites that are thick, highly porous, or that have rough or highly textured surfaces. For these materials Practice E664/E664M may be appropriate. Guide E1495/E1495M is recommended for assessing attenuation differences among composite plates and laminates that may exhibit, for example, pervasive matrix porosity or matrix crazing in addition to having complex fiber architectures or thermomechanical degradation (3). The proposed ASTM Standard Practice for Measuring Ultrasonic Velocity in Advanced Ceramics (C1331) is recommended for characterizing monolithic ceramics with significant porosity or porosity variations (4).

Subcomité:

E07.06

Volúmen:

03.03

Número ICS:

81.060.30 (Advanced ceramics)

Palabras clave:

attenuation coefficient; attenuation spectrum; material microstructure; materials characterization; monolithic ceramics; nondestructive evaluation; polycrystalline metals; pulse-echo technique; ultrasonic attenuation; ultrasonics;