Alumina fibers alpha

Other manufacturers have modified the production technique to reduce the diameter of the alpha-alumina fibers that they have produced. This reduction of diameter has an immediate advantage of increasing the flexibility and hence the weaveability of the fibers. Mitsui Mining and 3M Corporation have introduced polycrystalline fibers, the Almax and the Nextel 610 fibers with diameters of 10 p.m, that is half the diameter of Fiber FP. 

Almax Fiber An alpha-alumina fiber which is still commercially available was produced first in the early 1990s by Mitsui Mining (7). It is composed of almost pure alpha alumina and has a diameter of 10 xm. The fiber has a lower density of 3.60 g/cm compared to Fiber FP. Like Fiber FP the Almax fiber consists of one population of grains... 

Fig. 7 Creep-resistance of the eutectic fiber consisting of interpenetrating phases of alpha-alumina and yttrium-aluminum-garnet (YAG) up to very high temperatures compared with other types of oxide fibers... 

For refractory insulation applications heat treatments of the fiber above 1000°C induce the delta alumina to progressively change into alpha alumina. After 100 hours at 1200°C, or one hour at 1400°C, acicular alpha alumina grains can be seen on the surface of the fiber and mullite is detected. After 2 hours at 1400°C the transformation is complete and the... 

The Nextel 720 contains the same alumina to silica ratio as in the Altex fiber, that is around 85% wt AI2O3 and 15 % wt Si02- The fiber has a circular cross section and a diameter of 12 im. The sol-gel route and higher processing temperatures have induced the growth of alumina rich mullite and alpha alumina. Unlike other alumina-silica fibers the Nextel... 

Alpha alumina, 600, 605-607 Alpha parameter. See a parameter Alumina. See Aluminum oxide Aluminate fiber, 863 Aluminoborosilicate fiber, 863 Aluminoslicate ester, 218 fiber, 863... 

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