Helium Bubbles and Blistering in a Nanolayered Metal/Hydride Composite

Abstract

Helium is insoluble in most metals and precipitates out to form nanoscale bubbles when the concentration is greater than 1 at.%, which can alter the material properties. Introducing controlled defects such as multilayer interfaces may offer some level of helium bubble management. This study investigates the effects of multilayered composites on helium behavior in ion-implanted, multilayered ErD2/Mo thin film composites. Following in-situ and ex-situ helium implantation, scanning and transmission electron microscopy showed the development of spherical helium bubbles within the matrix, but primarily at the layer interfaces. Bubble linkage and surface blistering is observed after high fluence ex-situ helium implantation. These results show the ability of metallic multilayers to alter helium bubble distributions even in the presence of a hydride layer, increasing the lifetime of materials in helium environments.

The Influence of Crystal Orientation and Thermal State of a Pure Cu on the Formation of Helium Blisters

“…depends on the trapping energy. The bombardment of helium and its accumulation in the metal result in the sputtering, blistering, and erosion of the material's surface and ultimately the degradation of its structural and mechanical properties [8][9][10][11]. Thus, it is important to select a material for the PFC that will be able to withstand these processes.…”

Compositional Effects of Additively Manufactured Refractory High-Entropy Alloys under High-Energy Helium Irradiation

“…However, material microstructures can be engineered to tolerate the helium irradiation environment to mitigate the effects of He bubble accumulation. Strategies for limiting helium bubble effects in metals include decreasing the grain size [11,12], intentionally controlling the columnar microstructure [13,14], alloying [15,16], and introducing second phase interfaces/interphases [17][18][19]. Trapping He bubbles at the second phase precipitates or at interfaces in layered composites can mitigate the He effects in the matrix and may be more stable at high temperatures.…”