Low thermal conductivity Y2Ti2O7 as a candidate material for thermal/environmental barrier coatings. Issue 9 (July 2016)

• Record Type: Journal Article
• Authors: Nguyen, Son Thanh; Nakayama, Tadachika; Suematsu, Hisayuki; Suzuki, Tsuneo; Takeda, Masatoshi; Niihara, Koichi
• Is Part Of: Ceramics international. Volume 42:Issue 9(2016)
• Page Start: 11314
• Page End: 11323
• Publication Date: 2016-07
• Subjects: B. Composites -- C. Mechanical properties -- D. TiO2 -- D. Y2O3 -- Thermal/environmental barrier coatings; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2016.04.052
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Ceramic matrix composites of yttrium titanate (Y2 Ti2 O7 ) with nickel (Ni) or silicon carbide (SiC) were synthesized to investigate their potential as candidate materials for thermal/environmental barrier coatings. The composites were sintered by hot-pressing at 25 MPa. The mechanical properties of the composites including bulk density, Vickers hardness, and fracture toughness were evaluated. The measurements indicated that the incorporation of Ni or SiC has a positive effect in terms of enhancing the fracture toughness of the composites. Microstructural observations revealed that Y2 Ti2 O7 /Ni is an inter/intra nanocomposite, while Y2 Ti2 O7 /SiC has characteristics of a network microstructure composite. In addition, X-ray diffraction and energy dispersive X-ray spectroscopy analyses confirmed Y2 Ti2 O7 was chemically stable against Ni, but reacted with SiC to form silicates during the sintering process. The mechanisms for these reactions are also proposed.