Work

An engineering perspective on evaluating mechanisms governing ductility in pure molybdenum

Year: 2025

Type: article

Abstract: The United States lacks a stable domestic supply of 99 mTc, a critical medical imaging isotope generated from 99 Mo. Accelerator-based production using 100 Mo targets (aMo) introduces mechanical concerns due to the ductile-to-brittle transition temperature inherent to refractory metals like Mo. This study evaluates the tensile behavior of aMo targets from 25 to 1000 °C, compared to powder-metallurgy-processed natural Mo (PMo) and cast-and-rolled Mo (RMo), both as-received and after 5 ppm O 2 exposure in flowing He. RMo showed superior ductility (7.3% at 25 °C, 48% at 1000 °C) and strength, attributed to its fine, elongated grains and high geometrically necessary dislocation density. PMo exhibited variable ductility (up to 33%), while aMo remained brittle, with a maximum elongation of 10.4% at 600 °C. EBSD analysis revealed weak texture in PMo and aMo, but high defect density in aMo limited dislocation mobility. This work links processing, microstructure, and deformation mechanisms to guide fabrication of ductile refractory targets. Graphical abstract

Source: Journal of materials research/Pratt's guide to venture capital sources

DOI: 10.1557/s43578-025-01672-x

Authors: Holden C. Hyer, Sebastien Dryepondt, Thomas R. Muth, Jim Nash

Institution: Oak Ridge National Laboratory

Language: English

Topic: Microstructure and mechanical properties

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,490

Funder: National Nuclear Security Administration