Saffil

Properties Fiber FP PRD-166 Saffil RF Saffil HA Safimax Fiberfrax Nextel 312 Nextel 440... 

ICI Co. uses a sol-gel method to produce silica-stabilized alumina (Saffil) and calcia-stabilized zirconia fibre [15], The saffil fibre is a 8-alumina short staple fibre that has about 4% Si02 and a very fine diameter (3 pm). 

For Saffil alumina fiber, aluminum oxychloride [Al2(OH)jCI] is mixed with a medium molecular weight polymer such as 2wt% polyvinyl alcohol. The aqueous phase contains an oxide sol and an organic polymer. The sol is extruded as filaments into a coagulating (or precipitating) bath in which the extruded shape gels. The gelled fiber is then dried and calcined to produce the final oxide fiber. This solution is slowly evaporated in a rotary evaporator imtil a viscosity... 

Saffil. TM for a group of synthetic inorganic fibers made from alumina and zirconia. 

C n.m.r. has been used to follow the formation of Ni particles by decomposition of Ni(CO)4 on supports, e.g. I.C.I. Saffil, alumina, and zeolites. The Ni particles can be prepared in a highly dispersed highly microporous form. 

The creep data for the AZ 91 and QE 22 alloys and the AZ 91 + Saffil and QE 22 + Saffil composites at a testing temperature of 473 K are shown in Fig. 2a, where the minimum creep rate em is plotted against the applied stress a on a logarithmic scale. Inspection of the creep data in Fig. 2a leads to two observations. First, the AZ 91 + Saffil composite exhibits improved creep... 

Fig. 2b shows the variation of the time to fracture with the stress for the same specimens tested in Fig. 2a. The results for AZ 91 alloy and its composite demonstrate the creep life-times of the composite may be up to one order of magnitude longer than those for the monolithic alloy although this difference decreases with increasing applied stress so that ultimately there is very little difference at stresses >100 MPa. By contrast, the creep life of the QE 22 + Saffil composite is markedly shorter than that of the unreinforced alloy at stresses > 100 MPa. The presence of a reinforcement leads to a substantial decrease in the overall ductility of matrix alloy. Thus,...

The presence of short fiber reinforcement leads to a reduced creep rate in the AZ 91 + Saffil composite by two to three orders of magnitude (Fig. 4). Such a difference can arise when significant load transfer partitions the... 

CVH engine 3.60 mm mat gap 4070 Series IV mat Saffil edge seal Improved flow pipe Mat Loss... 

The Saffil fiber which contains 4% of silica is produced by the blow extrusion of partially hydrolyzed solutions of some aluminum salts with a small amount of silica, in which the liquid is extruded through apertures into a high velocity gas stream. The fiber contains mainly small 8-alumina grains of around 50 run but also some a-alumina grains of 100 run. The widest use of the Saffil type fiber in composites is in the form of a mat which can be shaped to the form desired and then infiltrated with molten metal, usually aluminium alloy. It is the most successful fiber reinforcement for metal matrix composite. 

The alumina based fibers discussed in section 3.2 possess a range of compositions. They can be short, as with the S affil fibers or continuous, as with the others described. Their properties at room temperature depend on the ct-alumina content and at high temperature, the presence of any second phase (31). The Saffil fiber contains a few percent of silica with the remainder of the composition being alumina in one of its transition phases or as a mixture of transition phases and a-alumina. Table 7 shows the changes in processing of fibers of this type (32).The properties of alumina based fibers areshown in Table 8. Figure 3 shows the tensile curves of a pure a-alumina fiber, the Fiber FP, which had a grain size of 0.5 p,m (23). 

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