建筑用玻璃与可伐合金润湿规律

为实现建筑用玻璃与可伐合金的可靠激光封接,本文针对影响封接质量的主要因素(温度、时间、粗糙度及氧化层)对两者润湿性能的影响开展了研究.当保温温度由800℃提高至900℃,液态玻璃黏度降低致使其在可伐合金表面的流动性增强,润湿角由69.5°降低至31.1°.在850℃下延长保温时间(5~40 min),液态玻璃在低黏度条件下有充分的时间铺展,润湿角降幅为30%.随着可伐合金表面粗糙度的提高,液态玻璃向四周扩散需要克服的势垒增加,当粗糙度值Ra由0.186μm升至0.563μm时,润湿角由46.9°升至69.5°.由于可伐合金表面氧化层可与液体玻璃发生扩散而形成较强离子键,使得两者润湿性能显著提高,润湿角降低幅度达到23.6%.因此,在实际激光封接过程中,增加保温温度和时间、降低钢板表面粗糙度及钢板预氧化处理将有效地提高玻璃与钢板的润湿性能.

Wetting behavior of constructional window glass and Kovar alloy

In order to realize reliable sealing and combination of constructional glass and Kovar alloy, the effects of temperature, holding time, roughness and oxide layers on their wetting property were studied. When the temperature increased from 800℃ to 900℃, the viscosity of liquid glass reduced, so the wetting angle decreased from 69. 5° to 31. 1°. When the holding time prolonged from 5 min to 40 min at 850℃, the liquid glass had enough time to diffuse under the condition of low viscosity, and the wetting angle increased by 30%. With an increase in roughness of steel sheet surfaces, the barrier increased which was needed to overcome by the liquid glass to spread around. When the roughness value Ra increased from 0. 186μm to 0. 563μm, the wetting angle increased from 46. 9° to 69. 5°. The oxide layer on the surface of Kovar alloy and the liquid glass had diffusion reaction that could form strong ionic bonds, which increased the wetting property considerably, and the wetting angle could decrease by 23. 6%. Therefore, during the actual seal-ing process, increasing the temperature and holding time, decreasing the roughness of steel sheet surfaces, and steel sheet pretreat-ment could effectively improve the wetting property of the glass and Kovar alloy.