Neutron irradiation poses a substantial challenge in the development and application of tungsten (W) and its alloys, predominantly in the framework of nuclear fusion and fission environments. Although W is well-acknowledged for its unique properties like its high melting temperature and higher resistance to sputtering, transmutation products, such as Re and Os, form and impact the alloy properties as a result of neutron irradiation. This transmutation effect accompanied by significant microstructure damage due to neutron irradiation can lead to the significant degradation of mechanical properties. This review surveys the literature focusing on the microstructural modifications post-irradiation and its impacts on the irradiation hardening. This review provides insights into the elaborative understanding on the neutron radiation damage on W and W alloys by exploring the microstructural evolution and hardness changes post-irradiation. The gaps and future opportunities for understanding neutron radiation damage in W are briefly summarized

Currently, metallic powders for laser powder bed fusion (LPBF) primarily come in two commercially available powder size distributions (PSDs): 15+/45− for non-reactive powders and 15+/63− for reactive powders. These powders are generally produced via gas atomization processes that create highly spherical particles with a Gaussian PSD. Because of the standard deviation within a Gaussian distribution, only small portions of the total product are used for LPBF applications. This screening process makes the other particle sizes a waste product and, thus, increases processing costs. The non-reactive 718 powder was printed with both the typical PSD of 15+/45− and a wider bimodal experimental PSD. Compared to conventional 718, the 718 alloys with bimodal PSD shows less than a 0.2% difference in density, and insignificant change in mechanical behavior. Electron backscattered diffraction studies revealed that grain sizes and morphology were similar between the two sample sets, but bimodal 718 alloy has a slightly greater degree of large grains. The study suggests that particles with wide or bimodal size distributions show promise in producing equivalent high-quality products without sacrificing mechanical properties.

Nanotwinned metals have exhibited many enhanced physical and mechanical properties. Twin boundaries have recently been introduced into sputtered Al alloys in spite of their high stacking fault energy. These twinned Al alloys possess unique microstructures composed of vertically aligned Σ3(112) incoherent twin boundaries (ITBs) and have demonstrated remarkable mechanical strengths and thermal stability. However, their strain rate sensitivity has not been fully assessed. A modified nanoindentation method has been employed here to accurately determine the strain rate sensitivity of nanotwinned Al–Zr alloys. The hardness of these alloys reaches 4.2 GPa while simultaneously exhibiting an improved strain rate sensitivity. The nanotwinned Al–Zr alloys have shown grain size-dependent strain rate sensitivity, consistent with previous findings in the literature. This work provides insight into a previously unstudied aspect of nanotwinned Al alloys.