Effect of scale and temperature dependence of the strength of basalt stone castings

Autor: I. I. Bykov, A. N. Pilyankevich, A. F. Beloivan
Rok vydání: 1969
Předmět:
Zdroj: Strength of Materials. 1:519-522
ISSN: 1573-9325
0039-2316
Popis: 1. The strength of stone castings of the composition investigated here depends on the size of the specimens tested. Thus, in testing the pure bending strength of the specimens the value alters from 750 to 413 kg/cm2 with a change in the working volume of the specimen from 0.46 to 29 cm3. In this case with an increase in the specimen volume the strength limit diminishes according to the W. Weybull theory. In compression testing only within a certain specimen-size range, the strength of the material depends on the scale effect, that is, the curve has a minimum. 2. We established a tendency for a reduction in the limiting strength of stone castings with increase in the test temperature: processing the results of the studies using the mathematical statistical method showed that the measured values for the limiting strength of the cast material proved to be very different only for two temperature ranges: 20-500° and 550-900°. 3. In the rupture of stone castings different mechanisms play a part: the particular failure mechanism predominates depending on the test temperature. As shown by electron microscopic research data in the temperature range 20-500° the transcrystallite failure mechanism predominates. An increase in the test temperature produces a predominance of the intercrystallite failure (across the glassy phase). At temperatures close to 900°C failure may occur across the grain boundaries.
Databáze: OpenAIRE
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