Dislocation Loops and Hardening of Silicon Ion Irradiated W and W-3Re Alloy at 400 °C and 550 °C

Si2+ irradiation with the dose of 33.8–100 dpa was used to study the dislocation loops and hardening in W and W-3Re alloy at 400 °C and 550 °C using transmission electron microscope (TEM) and nano-indentation tests. When irradiated at 550 °C, larger dislocation loops and numerous dislocation network formed with the dose increased from 33.8 dpa to 100 dpa for both materials. The density of dislocation loops might be saturated between 33.8–100 dpa for W and saturated at ∼53.8 dpa for W-3Re alloy. Compared with pure W, the mean size of dislocation loop was smaller in W-3Re alloy when irradiated to 33.8 dpa for both temperatures. Meanwhile, it was found that the irradiation hardening rate of W was larger than that of W-3Re alloy under the same irradiation conditions, indicating that the addition of 3 wt.% Re element could indeed decrease the irradiation hardening rate of W. The hardening rate might be saturated after ∼53.8 dpa irradiation for W-3Re alloy, which might be related to the saturated loop densities.