Scope:

ASTM C1525 quantitatively determines ceramic specimen material’s ability to withstand extreme and rapid changes in temperature by measuring the reduction in transverse rupture strength. The ceramic specimen is exposed to a varied range of temperature through rapid water quenching. However, ASTM C1525 does not test the specimen’s resistance towards steady-state temperature differences and recurring thermal shocks.

Test Procedure:

ASTM C1525 works on the principle of prompt quenching of the ceramic test specimen at differing temperatures through water bath. Initially, thermal shock is applied on the ceramic material at a predefined temperature for a few minutes. The specimen is  then quickly transferred into a water bath at room temperature and kept there for some time. After the thermal shock, specimens are cleaned and dried before measuring its flexural or bending strength. This computation is very useful for grading the quality of ceramic material, material development, assessment of its durability, and finally its characterization. Since it works on evaluating the retained strength, ASTM C1525 is not suitable for whole ceramic components but only test specimens.

Sample size:

For the precracked beam method in ASTM C1421, the test specimen must have a cross-section of 3 mm by 4 mm. ASTM C1525 primarily uses monolithic ceramics. It can also be extended to certain composites such as whisker or particulate reinforced ceramic matrix composites that are macroscopically homogeneous.

Data:

Data analysis of ASTM C1525 uses values conveyed in accordance with the International System of Units (SI) and IEEE/ASTM SI 10. Characteristic curve between flexural strength and number of cycles gives retentivity of the considered ceramic specimen.

Conclusion:

Hence, ASTM C1525 is a standard test method for determination of thermal shock resistance for advanced ceramics by water quenching.