Crown glass composite material with low thermal expansion coefficient

Abstract

The present invention relates to a glass composite material with linear thermal expansion coefficient alpha(20-300) of 1.8*10<-6>K<-1> to 2.4*10<-6>K<-1> and glass transition temperature Tg less than 650 DEG C. The glass composite material comprises the following components in weight percentage based on the content of oxides: 5-9 of B2O3; 1-3 of Na2O; 15-22 of Al2O3; 61-68 of SiO2; 0.2-0.5 of K2O; and 5.5-8.5 of MgO. The glass composite material can be prepared through sintering a mixture of 40-60wt.% of borosilicate glass powder and 60-40wt.% of iolite powder. The powder mixture can be used for preparing a glass solder which is used for connecting component, for preparing a sintered body which has thermal shock, or used for the glazing or braze welding of the PZT ceramic.

Description

Background technique

[0001] A subject of the present invention is a lead-free glass composition with a low coefficient of thermal expansion.

[0002] Glass composites are known per se. They are primarily used as glass solders for joining applications. They are made of glass powder to which an inert filler material is added to affect the coefficient of thermal expansion. The coefficient of thermal expansion of the solder can be changed or adjusted by means of these filling materials to achieve the thermal expansion coefficient of the metal, glass or ceramic components connected with the glass solder. The solder (ie glass phase) usually crystallizes at higher filler content. In said uncrystallized so-called stable glass solders, the glass content of the solder remains glassy. Typically, the amount of filler material added is limited by the unavoidable damage to solder flow capability produced by the additional filler material. Summary of the invention

[0003] The object ...