Slurry impregnation

In the slurry impregnation method, which adheres in part to a patented procedure,35 the ratio of the volume of loading solution used to the weight of alumina was 1 1, such that approximately 2.5 times the pore volume of solution was used... 

Co/y-A1203 Catalox SBA150 Slurry impregnation Narrow pore 127 0.37 9.3... 

A2 + D2) (B2 + D2) Powder or slurry impregnation Impregnated fleece Impregnated textile fabric Thermoforming Hot pressing Yes... 

Domier of Germany developed oxide fiber-reinforced mullite matrix composite systems in the 1980s. The system was based on SMs Nextel 312 fibers and slurry impregnation of a mullite matrix. This composite demonstrated modest levels of strength (120 MPa [17.4 ksi]) and low failure strain (0.2 to 0.3 percent). Several hot gas exhaust nozzles for Dormer s turboprop airerafl were successfully deployed and continue to be used in regular service. 

FIGURE 5. The standard slurry impregnation and hot-pressing route to fabricate fibre-reinforced glass matrix composites [105]. 

Pull-pressing uses a modified form of filament winding [74] where a slurry impregnated carbon fiber tow is fed into a mold and consolidated to form sheets or beams. 

Basically, processing can be divided into the powder and chemical routes. The powder route includes sintering, slurry impregnation and reaction bonding, whilst the chemical route includes CVI, direct oxidation, sol gel and polymer pyrolysis. Final consolidation and densification must be achieved at high temperature. The powder route produces higher density ceramic matrix composites and the chemical route produces better quality. 

The teehnique used for slurry infiltration is the same as that used for glass (Section 15.3.2.2) and to improve the densification, it is normal to adopt a multiple slurry impregnation process. The technique is most effective for glass ceramics, although recent attention has concentrated on SiC reinforcement. A limitation when coating continuous fiber is that the impregnated and dried tow has an excess of matrix particles, which persists after densification. 

Figure 36 Effect of M0O3 and impregnation method on relative HDS activity slurry impregnation of AC, O slurry impregnation of AI2O3, (x) conventional impregnation of AI2O3 (10.3 M0O3), 3 conventional impregnation of AC (12.4 M0O3), (J> reference catalyst.

Hillerovd, E., Morishige, H., Inamura, K., and Zdrazil, M. Formation of mono-layer of molybdena over alumina by unconventional slurry impregnation or solvent assisted spreading method, Catal. A Gen. 1997,156, 1-17. 

J. MagnanL R. Pailler, Y. Le Petitcorps, L. Mailld, A. Guette, J. Marthe, and E. Philippe, Fiber-reinforced ceramic matrix composites processed by a hybrid technique based on chemical vapor infiltration, slurry impregnation and spark plasma sintering, J. Eurt. Ceram. Soc., 33, 181-190... 

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