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Using polystyrene spheres to produce thin, porous interlayers in alumina laminates
Publikationstyp
Journal Article
Date Issued
2022-05
Sprache
English
Volume
19
Issue
3
Start Page
1453
End Page
1461
Citation
International Journal of Applied Ceramic Technology 19 (3): 1453-1461 (2022-05)
Publisher DOI
Scopus ID
Publisher
Wiley-Blackwell
Porous alumina layers were produced by colloidal processing of alumina with the addition of 15, 30, and 45 vol% polystyrene spheres (PS) as pore formers. Alumina laminates were designed with dense layers alternated with porous interlayers using 45 vol% of PS spheres and sintered at 1350°C. The layers’ thickness ranged from 2 to 15 μm, with a random distribution of pores. The higher volume fraction of pores tends to decrease the alumina average grain size, but does not influence the final size of bulk and surface pores. The obtained values of hardness and Young's modulus for the porous interlayer are ∼30% of the values obtained for the dense layer. Vickers indentations suggested that crack propagation can be opposed by the porous interlayers. However, values of mechanical strength, fracture toughness (KIC), and work of fracture presented no relevant difference compared to a monolithic reference. R-curves presented a slight increase and KIC a decrease due to crack propagation through the porous interlayers. Although no macrodeviations of the crack path were observed in the fractured surfaces, microdeviations were detected in the interlayer regions.
DDC Class
600: Technik
Funding Organisations
More Funding Information
This work was supported by the International Cooperation Program Probral at the Hamburg University of Technology, which was financed by the Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES), and the German Academic Exchange Service (DAAD)