Structure and Stability of Synthetic Interphases in CMCs

Interfacial reaction behavior and thermal stability of barium zirconate-coated alumina fiber/alumina matrix composites

“…17 These are exemplified by vanadates, phosphates or niobates, having a general formula MXO 4 (M = La, Y or Nd; X = P, Nb or V). [18][19][20][21][22] (3) Hexaluminates with a layered crystal structure, such as CaAl 12 O 19 and LaAl 11 O 18 . [23][24][25] These oxide coatings are chemically inert at elevated temperatures with respect to both Al 2 O 3 fiber and Al 2 O 3 matrix.…”

The influence of fiber coating conditions on the mechanical properties of alumina/alumina composites

“…Furthermore, the monazite / alumina ber interface has shown low enough fracture resistance to satisfy the debonding requirement during fracture of the composites [13]. The other oxide compounds, MXO 4 (M: Y, La or Nd; X: P, Nb or V), which show similar properties to those of monazite, have also been considered as candidates for the oxide ber interlayer to obtain the optimum mechanical and physical performance [14,15]. Typical physical properties of YPO 4 , CePO 4 and LaPO 4 are summarized in Table 1.…”

In situ synthesis of alumina-matrix oxide/oxide composites by reactive sintering

“…A fiber/matrix interfacial layer in CMCs is generally obtained through incorporation of a coating layer on fibers. In oxide/oxide systems, various oxide compounds have been proposed as candidates for coating materials, which include (1) simple oxides, such as SnO 2 [10][11][12], ZrO 2 [13,14], TiO 2 [15], and CeO 2 [16]; (2) complex oxides which have a high probability of low cohesion with matrix or fiber due to the polarization of oxygen bonds by high valence cations [8], for example, vanadates, phosphates or niobates, having a general formula MXO 4 (M ¼La, Y or Nd; X¼ P, Nb or V) [17][18][19]; and (3) hexaaluminates with a layered crystal structure, such as CaAl 12 O 19 and LaAl 11 O 18 [2,3,20]. These oxide coatings are chemically inert at elevated temperatures with respect to both Al 2 O 3 fiber and Al 2 O 3 matrix.…”