Enhanced sintering of tungsten. (January 2023)

• Record Type: Journal Article
• Authors: Johnson, John L.
• Is Part Of: International journal of refractory metals & hard materials. Volume 110(2023)
• Publication Date: 2023-01
• Subjects: Tungsten -- Oxide-dispersion strengthening -- Solid-state sintering -- Activated sintering -- Field-assisted sintering -- Grain growth; 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.2022.106017
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: W and W-La2 O3 powders with a range of particle sizes were processed by furnace sintering, direct resistance sintering, and spark plasma sintering to determine the effects of current and pressure on densification and grain size. The results from these experiments are combined with experimental data from literature and compared to a model for densification based on master sintering curve concepts to assess the effectiveness of finer particle sizes, the application of current, and the combined application of current and pressure for achieving sintered densities above 96% of theoretical for pure tungsten and for tungsten containing small amounts of oxides and/or carbides. Experimental results for grain size are also compared to the model predictions for pressureless sintering. The same model is used to assess the effectiveness of transition metal additions, the application of pressure, and the application of electromagnetic radiation on enhancing the sintering of tungsten and refining its grain size. Highlights: W and W-La2 O3 powders are processed with different sintering techniques. Several sintering techniques are assessed using a master sintering curve model. Experimental results for sintering of W and dispersion strengthened W are analyzed. Submicrometer powders, pressures above 200 MPa, and transition metal additions enhance densification of W. Electrical current, microwaves, and lasers do not provide obvious sintering enhancement.