Transparent Ceramics for Visible/IR Windows: Processing, Materials and Characterization

Preparation and study of the mechanical and optical properties of infrared transparent Y2O3–MgO composite ceramics

“…23,[31][32][33][34][35][36][37][38] T in these cases to determine the resin flow ing times corresponding to different infilt Preceramic polycarbosilane polymers as precursors to make ceramic fibers 10,3 trix. [7][8][9]40,41 The chemical and volume ch pany ceramization of the polymer during documented in several studies. A survey of the published literature shows that process modeling of CMCs has been studied by a number of researchers.…”

“…Fillers are typically added in a range of 20-50 weight percent to increase the yield of the prepreg matrix, and also to tailor properties of the CMC. The prepregged fabric was next cut [1][2][3][4][5][6][7][8] However, future IR transparent windows and domes operating in harsher mechanical and thermal environments require materials with increased mechanical strength, improved thermal shock resistance, and low emissivity compared with those available today. 9 Polycrystalline Y 2 O 3 ceramic is the material of choice for IR windows and domes because it is readily available and characterized by low emissivity and remarkable high-temperature optical transmittance.…”

“…30 Presintering helps green bodies achieve a certain degree of densification, and post-HIP treatment helps remove residual pores to achieve full densification. 8,[31][32][33][34] As we know, the literatures have not previously reported the use of solgel method and HIP treatment after pre-sintering together for infrared-transparent Y 2 O 3 -MgO composites.…”

“…Preceramic polycarbosilane polymers are commonly used as precursors to make ceramic fibers 10,39 and ceramic matrix. [7][8][9]40,41 The chemical and volume changes that accompany ceramization of the polymer during pyrolysis have been documented in several studies. For example, see Refs [39][40][41][42].…”

Crystallization of glass materials into transparent optical ceramics

“…The combination of moderate pressure and high temperature during sintering produces better contact between particles in the powder compact through particle rearrangement, thereby enhancing densification with respect to the coarsening process, particularly in the final stages of sintering. The material transport occurring during the pressure-assisted sintering, mainly grain boundary and volume diffusion, is greatly aided by the plastic deformation and creep mechanisms [74]. Simultaneous action of these processes contributes to very rapid densification rates, thus resulting in a grain growth inhibition effect and enabling the fabrication of fine-grained ceramics with many superior properties, including high mechanical strength.…”