Brittle composites modeling: Comparisons with MoSi{sub 2}/ZrO{sub 2}

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:10112653

Chen, S P

We have calculated the mechanical properties of brittle composites with spring-network (SN) model. The composites that we studied involve the transformation toughening effects and the accompanying micro-cracking. Our simulation results are consistent with experiments of MoSi{sub 2} toughened with ZrO{sub 2}. We found that the continuum mechanics predictions on linear dependence in e{sup T} and f about the transformation toughening are correct except some differences in the critical transformation stress dependence. By monitoring the stress changes due to the transformation and micro-cracking we are able to separate, for the first time, the contributions from these two competing effects. We found that the fracture toughness due to micro-cracks accompanying the transformation is a decreasing function of f and may be negative for large f. We also found that the fracture toughness of the composites increases as the modulus, interfacial cohesion, and uniformity of particle distributions increases.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10112653
• Report Number(s): LA-UR--93-4307; CONF-931108--43; ON: DE94004978
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603
COMPOSITE MATERIALS
DISPERSION HARDENING
FRACTURE PROPERTIES
MECHANICAL PROPERTIES
MOLYBDENUM SILICIDES
PARTICLES
SIMULATION
ZIRCONIUM OXIDES