FRACTURE STRESSES OF UO2-TUNGSTEN CERMETS EVALUATED BY THE DIAMETRAL TENSILE TEST INTERIM REPORT 1

摘要

Pneumatically impacted UO2 -tungsten cermets in a composition range from pure tungsten (particle size of 5 microns) to tungsten50 vol% UO2 (particles size of 44 - 75 microns) were tested by the diametral tensile test at room temperature. The tensile fracture stresses decreased from 22, 000 to 14, 000 psi as the composition varied from pure tungsten to tungsten-50 vol% UO2 Results of the diametral tensile test are usually lower than the values of the direct pull tensile test and the modulus of rupture test. The average fracture stress of a 20 vol% UO2 tungsten cermet was 45, 690 psi by the modulus of rupture test and 18, 400 by the diametral tensile test.nBecause of the preferential alignment of elongated UO2 particles during pneumatic impaction, the tensile fracture stresses were orientation-dependent with respect to the pneumatic impaction direction.