The effect of ball milling on properties of sintered manganese-doped alumina
Authorized Users Only
2019
Authors
Filipović, Suzana
Obradović, Nina

Marković, Smilja

Mitrić, Miodrag

Balać, Igor
Đorđević, Antonije
Pavlović, Vladimir B.

Article (Published version)

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Alumina-based compounds have many technological applications and attract great attention even after decades of investigation, due to their good chemical, electrical, and mechanical properties. A mixture of several alumina modifications (α-, κ-, γ-Al2O3) doped with 1 wt% of Mn2O3 was used for this experiment. The powder was mechanically activated for 60 min in an ethanol medium. After compaction, green bodies were sintered in the temperature range from 1200 to 1400 °C. Microstructures of the obtained specimens were investigated by scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDS). The influence of morphological changes on electrical and mechanical properties was examined in detail. We have developed a test fixture and corresponding software for measurement of the relative dielectric permittivity and the loss tangent of ceramic specimens. This new method overcomes the problems of dimensions and shape of samples, as well as the problem of applying silver pa...ste. The accuracy is around 2% for ε'r and 0.003 for tanδ. We demonstrate that the mechanical activation (MA) has the dominant influence on lowering the characteristic temperatures and microstructure development, which further leads to increased permittivity and tensile strength.
Keywords:
alumina / ceramics / properties / sinteringSource:
Advanced Powder Technology, 2019, 30, 11, 2533-2540Publisher:
- Elsevier
Projects:
- Directed synthesis, structure and properties of multifunctional materials (RS-172057)
- Synthesis, processing and applications of nanostructured multifunctional materials with defined properties (RS-45019)
DOI: 10.1016/j.apt.2019.07.033
ISSN: 0921-8831