HIGH-TEMPERATURE MECHANICAL-PROPERTIES OF C15 LAVES PHASE CR2NB INTERMETALLICS

High temperature deformation behavior of C15 Cr2Nb intermetallic compounds was observed by compression tests. These intermetallic compounds are deformable at temperatures above 1473 K. The flow stress decreases with increasing temperature and is little sensitive to small changes in alloy composition. Stress-strain curves are sensitive to temperature and also to the strain rate. At intermediate temperatures (also at intermediate strain rates) an apparent stress peak and a subsequent decrease in now stress were observed. At high temperatures (also at low strain rates) a steady state flow was observed immediately after yielding. The stress exponent in the constitutive equation is about 3.5 while the apparent activation energy is 470 kJ mol(-1). The activation of a consider able amount of dislocations was observed at temperatures where compressive plastic deformation is accomplished.