| 配方类型： |
CERAMICS AND GLASS |
| 配方说明： |
Zero-Shrinkage Ceramics |
| 配方组成： |
Spodumene/60
This body fired to 1970'F. (1077'C.) has zero absorption. The
shrinkage is also zero if the optimum pressure is used in fabrication
(22 tons per sq. in. using 200-mesh materials). Additions of clay up to
15% decrease the pressure required to 10 tons per sq. in. at which zero
shrinkage can be obtained. This type ceramic has a dielectric constant
of 6.4, a loss factor of 0.029 and a coefficient of linear thermal
expansion of 2.02x10^-^6 (77 to 842'F., 25 to 450'C.). With the optimum
forming conditions the fired part has the same dimensions as the die in
which it is formed.
An example of the other type of nonshrinking ceramic i
Lead Bisilicate/68.6
Kaolin/26.6
Alumina/4.8
Lead Bisilicate/40 |
| 配制方法： |
This ceramic depends on the formation of the crystalline phase of lead alumina silicate. It is dense and has zero absorption at 1700'F.
(927'C.). At 1950'F. (1066'C.) this ceramic is still dense and not overfired. thus having an unusually long firing range. There is some selfglazing at 1950'F. (1066'C.) and this self-glazing mechanism becomes pronounced at 1975'F. (1079'C.) This ceramic has zero shrinkage with the optimum forming conditions (33 tons per sq. in. using 200-mesh materials). The dielectric constant is 5.8 and the loss factor 0.006, thus affording a Grade L-5 ceramic with zero shrinkage. |
|
