Welding Tungsten Boat

Welding tungsten boat is also known as heating wolfram boat. Welding is connected directly to connecting position of the two metals together by the melting at high temperature. Heating and pressing five pieces of tungsten plates at a high temperature so that the connection can be melted together, cooling it after welding, forming the final shape of the boat. Welding of pure wolfram is generally divided into two processes: melting welding and brazing. During the melting welding, molten liquid of two workpieces will mix together under interaction of temperature field and gravity but without any pressure. Until the temperature decreases, the melted portion will condense, two workpieces will be firmly welded together to complete the welding. Brazing use metal material which has a lower melting point than the base material as the brazing filler metal, Heating the weldment and brazing filler metal to make its melting point higher than the melting point of brazing filler metal and lower than the melting temperature of the base material, using liquid brazing filler metal to wet the base metal, filling gap of joint and connect the base material. While welding, the joint of the wolfram plates is called soldering seam. Both sides of it would influenced by heating during soldering and organization and performance would change, this area is known as the heat affected zone.

Soldering is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing fusion, which is distinct from lower temperature metal-joining techniques such as brazing and soldering, which do not melt the base metal. In order to improve the quality of soldering wolfram boat, users can use argon, carbon dioxide and other gases to avoid atmosphere so that it can protect the arc and rate of furnace hearth while welding. Finally, a boat shape is formed by welding.

Its size is relatively large, so it can be used for large-scale evaporation device or a large number of material evaporation. Compared to riveting tungsten boat, soldering W-boat can save material of 10% -20%, and it doesn’t need to scribing, drilling, assembling, and other complex processes. Since welding tungsten boat is made of two or more plates, which cannot be made on one time, so the preparation time will be longer.