Alumina/molybdenum nanocomposites obtained by colloidal synthesis and spark plasma sintering. Issue 6 (15th March 2023)

• Record Type: Journal Article
• Authors: Fernández-González, D.; Suárez, M.; Piñuela-Noval, J.; Díaz, L.A.; Gómez-Rodríguez, C.; García Quiñonez, L.V.; Borrell, A.; Fernández, A.
• Is Part Of: Ceramics international. Volume 49:Issue 6(2023)
• Page Start: 9432
• Page End: 9441
• Publication Date: 2023-03-15
• Subjects: Ceramics -- Composite materials -- Sintering -- Mechanical properties -- Spark plasma sintering -- Alumina -- Cermets; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.11.108
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Alumina/molybdenum nanocomposites were prepared by colloidal synthesis from alumina powder and molybdenum (V) chloride using ethanol as dispersion medium. Modified alumina was calcined at 450 °C in air atmosphere to remove chlorides, and then treated in a tubular furnace at 850 °C under Ar/H2 to reduce the MoO3 formed in the previous stage and obtain Al2 O3 with molybdenum nanoparticles on the surface. Three different molybdenum contents were proposed (1, 5 and 10 wt % Mo), and pure alumina was used as reference, that were sintered by spark plasma sintering (SPS) under vacuum atmosphere at 1400 °C for 3 min with an applied pressure of 80 MPa. Composites were characterized by microstructure, hardness, toughness, and three-point bending test. The presence of molybdenum nanoparticles resulted in a fine-grained structure promoted by the presence of molybdenum at grain boundaries and triple points, as well as by the utilization of the SPS equipment. Hardness is at least a 20% greater and fracture toughness 30% larger in the composites than in the monolithic alumina.