Small scale mechanical testing of irradiated materials

Small specimen testing techniques have a long history in nuclear material research due to the limitations posed by nuclear facilities. The limited space in reactors and the fact that the samples are oftentimes radioactive in addition to the increasing need to obtain mechanical properties from ion beam irradiated samples require small specimen mechanical testing. With the application of modern focused ion beam sample preparation techniques and the enhancement of nanoindentation instruments, the size scale has been moved to even smaller scales and new geometries. Micrometer and even nanometer size samples are feasible, but raise the question of comparability to large scale properties for engineering applications. In this review, we summarize available small scale materials testing techniques and potential shortcomings based on examples from the literature, as well as introduce novel experimental approaches conducted using microcompression testing, microbend bar testing, and nanoindentation at ambient and nonambient conditions.