Exploring the Formation Mechanism, Evolution Law, and Precise Composition Control of Interstitial Oxygen in Body-Centered Cubic Mo

Interstitial oxygen (O) on the formation mechanism and enrichment distribution of body-centered cubic (BCC) molybdenum (Mo) has rarely been reported, O usually can cause serious brittle fracture in Mo. In this paper, we studied evolution when it was precisely controlled range 3700–8600 parts per million (wppm). It found that, with an increase concentration, element not only existed form solid solution but generated different valence states Mo metal. Large amounts MoO2, MoO3, Mo4O11 intermediate oxides were identified by electron probe micro-analyzer (EPMA) X-ray photoelectron spectroscopy (XPS). Thermodynamic calculations revealed process oxides, authenticity presence verified XPS. Enrichment analyzed scanning microscopy (SEM), energy dispersive (EDS), EPMA. Moreover, compressive yield strength hardness greatly affected content 4500–8600 wppm. Our study is helpful to understand behavior interstitial impurity refractory metals provides important guidance for development high-purity rare metals.