A study of the impact of reduction conditions on molybdenum morphology. (February 2018)

• Record Type: Journal Article
• Authors: Bolitschek, J.; Luidold, S.; O'Sullivan, M.
• Is Part Of: International journal of refractory metals & hard materials. Volume 71(2018)
• Page Start: 325
• Page End: 329
• Publication Date: 2018-02
• Subjects: Hydrogen reduction -- Pseudomorphic transformation -- Chemical vapour transport -- Molybdenum -- Molybdenum oxides -- Morphology; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2017.11.037
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: The current work concerns the influence of different reduction conditions (temperature, dew point and hydrogen content as well as flow rate of reduction gas) on the morphology of molybdenum powder. The material was produced by a two-stage reduction of different sized molybdenum trioxide particles with hydrogen. The experiments were carried out in a rotary kiln. It was found that the specific surface area is mainly influenced by temperature and decreases with rising temperature. The particle size of the raw material, the dew point as well as the hydrogen content of the reduction atmosphere not only have a significant influence on the morphology of the produced molybdenum powder, but also change the impact of the temperature. The results imply that the effect of a single reduction parameter on the properties of the resulting powder always has to be seen in context with the other reaction conditions. Graphical abstract: Highlights: Effect of reduction conditions on the emerging Mo morphology were investigated. MoO3 was reduced at different temperatures and compositions of the atmosphere. An increase in temperature promotes the formation of a coral morphology. Temperature was found to be the key factor influencing the specific surface area. A model equation was established to estimate the specific surface area.