Self-propagating welding of sapphire and Kovar by NiAl nano multilayers

The self propagating welding of Kovar and sapphire was carried out with NiAl nano multilayers. The samples were tested by X-ray machine, scanning acoustic microscope, scanning electron microscope and bonding tester. The results show that sapphire and Kovar can be well self propagating welded using multilayer NiAl nano multilayers as heat source and solder to form uniform weld joint. The void ratio of the weld joint is 1.1%, and the welding strength is ~ 3.38 MPa. This study lends credible the welding of sapphire and similar metal materials.