Titanium screw can be welded by contact welding without special preparation. When there is a thick oxide film, it needs to be mechanically cleaned or removed in 5% hydrofluoric acid solution.
The arc welding of titanium screw is carried out in clean gas weave (helium, argon), and the better result can be obtained by direct current. At this time, the tungsten electrode is the cathode.
Direct fusion of titanium screw with nickel, chromium bromide and other alloys containing nickel is not suitable, because harmful eutectic can be formed. In this case, gaskets with thicknesses of 15-20 microns, usually molybdenum, tantalum or niobium, need to be placed between materials of different properties. Under this condition, the titanium screw or component welded with nickel or nickel alloy can be annealed and degassed smoothly in vacuum or inert gas at a temperature of 1500 C.
This method can eliminate the contamination of the connection zone by other elements, because no special solder and no pre-metallization are needed in the welding process. It can obtain high quality vacuum compact connection, which is the most promising method for titanium screw.
