Dopant diffusion at the interface of TiO2‐MnO‐doped alumina/alumina layers in sintered laminates. Issue 3 (4th May 2021)

• Record Type: Journal Article
• Authors: Daniel Barros, Marcelo; Hotza, Dachamir; Janssen, Rolf
• Is Part Of: International journal of ceramic engineering & science. Volume 3:Issue 3(2021)
• Page Start: 105
• Page End: 112
• Publication Date: 2021-05-04
• Subjects: alumina -- diffusion -- dopants -- interface -- manganese oxide -- nanoindentation -- titanium dioxide; Ceramics -- Periodicals; Ceramics -- Research -- Periodicals; Ceramics -- Research; Electronic journals; Periodicals; 666.05
• DOI: 10.1002/ces2.10090
• Languages: English
• ISSNs: 2578-3270

Abstract

Abstract: Ceramic laminates were produced by thermal pressing of pure alumina (Al2 O3 ) and TiO2 ‐MnO‐doped alumina (d‐Al2 O3 ) tapes and subsequently sintered at temperatures ranging from 1100 to 1250°C. The diffusion of dopants through the interface was investigated by optical (OM), scanning electron (SEM) microscopy, nanoindentation, and energy‐dispersive X‐ray spectroscopy (EDS) together with scanning transmission electron microscopy. Temperature‐dependent dopant diffusion and porosity profiles were, respectively, observed investigating the microstructure. For d‐Al2 O3, the average grain size, hardness, and Young's modulus were higher when compared to pure alumina, while the dopants diffusion zone presented intermediate values of these properties. The increase in sintering temperature resulted in higher values of hardness and Young's modulus in both layers. A further investigation showed a gradual decrease in grain size, hardness, and Young's modulus from the doped to the pure alumina layer, corresponding to a decreasing gradient in the dopants concentration in the Al2 O3 layer with increasing distance from the interface. High concentrations of Mn and Ti were observed at triple points and grain boundaries, as well as within alumina grains. Abstract : Alumina laminates with alternating porous dense and layers are manufactured via tailoring the sinterability via co‐doping. Here, we report the diffusion from the doped to the undoped region during sintering with special emphasis on the resultant gradients on Young's modulus and hardness.