Glass/alumina composite

Relationship between strength and toughness for glass/alumina composites with best fit straight line to eq. (4.2). Data from [29],... 

Satisfactory clinical performance of In-Ceram dental restorations has been reported [23], and further improvement of the chemical durability and wear behaviour of these glass/alumina composites has been achieved by using diamond-like carbon coatings [17]. 

Further limitations to Lange s model are revealed when the effect of filler particle size on G (c) is considered. Lange himself [53] measured GJc) against Vf for three series of sodium borosilicate glass/alumina composites in which the average alumina particle size was 3.5 Xm, 11 pm and 44 pm, respectively. For any given value of Vf, GJc) increased... 

Figure 1.2 Glass/Alumina composite with 20 vol% alumina content. Dielectric constant of the composite is 5.6, thermal expansion coefficient is 3.5 x 10 /°C, thermal conductivity is 2.4 W/mK, and flexural strength is 200 MPa [Bar = 5 pm].

Figure 2-9 Sintered density of glass/alumina composite when 950 0 retention time is...

Figure 2-10 Microstructure of glass/alumina composite after heat treatment of950°C for 20 h, and 1,000°C, for 5 h [Bar = 200 pm].

Figure 2-11 Results of X-ray diffraction of a glass/alumina composite when the amount of alumina added is changed (a), and cristobalite crystals precipitated in glass (b) [Bar = I pm].

Figure 2-16 Phase formation when the composition and firing temperature of glass/alumina composite are taken as the parameters.

Figure 2-17 Flexural strength of glass/alumina composite when (a) composition (amount of ceramic), (b) porosity, and (c) dispersed particle diameter are varied.

Figure 2-20 EPMA results of a cross section of glass/alumina composite before and after ion exchange treatment (immersion in KNO3 at 400°C for 30 h).

Glass/alumina composite Alumina Borosilicate glass (Pyrex)... 

Figure 2-22 Thermal shock resistance of glass/alumina composite (a), and material microstructure after thermal shock fracture (b)...

Figure 2-23 Thermal conductivity of glass/alumina composite (actual measurement and calculated value). The numbers in the Figure correspond to the formula numbers.

In order to achieve high thermal conductance, aluminum nitride, silicon nitride, silicon carbide and the like which have high thermal conductance are being tried as ceramic ingredients. However whatever the type, it is difficult to exceed that of the alumina used in HTCCs. However, compared with resin materials, glass/alumina composites can achieve thermal conductivity more than ten times higher. 

Figure 8-8 Comparison of firing shrinkage behavior of glass/alumina composite and copper paste.

The four combinations above can be observed in an equilibrium, however in practice the ceramic part may appear black and the conductor part may appear reddish brown. If a glass/alumina composite using glass... 

Figure 8-17 A XM A profile of a blackened glass/alumina composite.

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