Evidence for a High Temperature Whisker Growth Mechanism Active in Tungsten during In Situ Nanopillar Compression

A series of nanopillar compression tests were performed on tungsten as a function of temperature using in situ transmission electron microscopy with localized laser heating. Surface oxidation was observed to form on the pillars and grow in thickness with increasing temperature. Deformation between 850 degrees C and 1120 degrees C is facilitated by long-range diffusional transport from the tungsten pillar onto adjacent regions of the Y2O3-stabilized ZrO2 indenter. The constraint imposed by the surface oxidation is hypothesized to underly this mechanism for localized plasticity, which is generally the so-called whisker growth mechanism. The results are discussed in context of the tungsten fuzz growth mechanism in He plasma-facing environments. The two processes exhibit similar morphological features and the conditions under which fuzz evolves appear to satisfy the conditions necessary to induce whisker growth.

Automated summary

In a series of nanopillar compression tests on tungsten, the effects of surface oxidation on deformation were studied using in situ heating, revealing a mechanism for localized plasticity. The results suggest that the constraint imposed by surface oxidation may lead to the growth of whiskers, similar to the whisker growth mechanism. The study also discussed the similarities between the tungsten fuzz growth mechanism and whisker growth in different conditions.