A model to evaluate the ductile-to-brittle transition of bcc-W based on small tensile test and dislocation characterization

In this study, we propose a model to evaluate the ductile-to-brittle transition (DBT) of W based alloy using small tensile test and dislocation density measurement. The new model is built upon the high correlation between the DBT and the dislocation multiplication. Compared the measured results from the typical testing methods such as small tensile test, three-point bending test, it reveals that the new model is close to the bending test results. Interestingly, the equivalent transition temperature (ETT) of W-Y 2 O 3 alloy measured by three-point bending test and the new model is lower than that of pure W. The effect of grain boundary and Y 2 O 3 particles on DBT were discussed, and the lower transition temperature of W-Y 2 O 3 alloy is attributed to the easier dislocation multiplication near grain boundary as well as the increase of small angle grain boundary.