Synthesis Of The Metal Oxide Enhanced Sealing Glass

After sufficient investigating the development and application demanding of the sealing glass and the glass-to-metal sealing, the paper mainly studied the effect of the metal-oxides on the attributes of the sealing glass and the sealing between the glass and Kovar by adding metal-oxides, which improved the sealing properties of DM-308 used to seal high vacuum relay.Firstly, the glass powder was prepared by high temperature melting. Then by sintering after cool pressing, the glass powder was transformed to the glass insulator. And the glass-to-Kovar was prepared by liquid phase sintering at high temperature. By means of XRD(X-ray Diffraction), DSC, SEM(Scanning Electron Microscopy), EDS (Energy Dispersive X-ray Spectroscopy), Archimedes and the granularity analyzer, the paper studied the ingredients, structure, properties of the glass powder, the glass insulator and the glass-to-Kovar.Secondly, the effect of the metal-oxides on the properties was studied. As a result, the mechanical properties of sealing glass were improved by 10%, and the bonding strength of the glass-to-metal was increased by 15.6%.Thirdly, the effect of the balls on the sintering of the powder was studied. The stainless-steel balls destroy the powder's properties so that it couldn't sinter at 1000℃ within too much time. The agate balls were better than the stainless-steel balls, the powder grinded by it can sinter at 700℃ within 10min. In this paper, when the grinding time was 1 hour, the property of the glass powder was good.As for the binder in pelletizing, the property of PVA was better than paraffin and ethylic cellulose. The angle of repose, the apparent density and compressibility were good after pelletizing with PVA.Furthermore, the effect of technics on the properties of the glass insulator also was studied. The powder's granularity, which should bigger than 7.2μm, was the key factor. The pressure was the second important factor.Finally, the paper discussed the sealing process between the glass and Kovar, which indicated that the flux of N₂ was an important factor to the quality of the sealing. The sealing temperature was the second important factor and the heat preservation was the third.