Titanium Joining

Shear strength evaluation of molybdenum- and titanium-joined SiC... 

Eabrication techniques must take into account the metallurgical properties of the metals to be joined and the possibiUty of undesirable diffusion at the interface during hot forming, heat treating, and welding. Compatible alloys, ie, those that do not form intermetaUic compounds upon alloying, eg, nickel and nickel alloys (qv), copper and copper alloys (qv), and stainless steel alloys clad to steel, may be treated by the traditional techniques developed for clads produced by other processes. On the other hand, incompatible combinations, eg, titanium, zirconium, or aluminum to steel, require special techniques designed to limit the production at the interface of undesirable intermetaUics which would jeopardize bond ductihty. 

Eigure 3 is a flow diagram which gives an example of the commercial practice of the Dynamit Nobel process (73). -Xylene, air, and catalyst are fed continuously to the oxidation reactor where they are joined with recycle methyl -toluate. Typically, the catalyst is a cobalt salt, but cobalt and manganese are also used in combination. Titanium or other expensive metallurgy is not required because bromine and acetic acid are not used. The oxidation reactor is maintained at 140—180°C and 500—800 kPa (5—8 atm). The heat of reaction is removed by vaporization of water and excess -xylene these are condensed, water is separated, and -xylene is returned continuously (72,74). Cooling coils can also be used (70). 

The electrolytic cells shown ia Figures 2—7 represent both monopolar and bipolar types. The Chemetics chlorate cell (Fig. 2) contains bipolar anode/cathode assembhes. The cathodes are Stahrmet, a registered trademark of Chemetics International Co., and the anodes are titanium [7440-32-6] Ti, coated either with mthenium dioxide [12036-10-17, RUO2, or platinum [7440-06-4] Pt—indium [7439-88-5] Ir (see Metal anodes). Anodes and cathodes are joined to carrier plates of explosion-bonded titanium and Stahrmet, respectively. Several individual cells electrically connected in series are associated with one reaction vessel. 

The most recently developed anode for the cathodic protection of steel in concrete is mixed metal oxide coated titanium mesh The anode mesh is made from commercially pure titanium sheet approximately 0-5-2mm thick depending upon the manufacturer, expanded to provide a diamond shaped mesh in the range of 35 x 75 to 100 x 200 mm. The mesh size selected is dictated by the required cathode current density and the mesh manufacturer. The anode mesh is supplied in strips which may be joined on site using spot welded connections to a titanium strip or niobium crimps, whilst electrical connections to the d.c. power source are made at selected locations in a suitably encapsulated or crimped connection. The mesh is then fitted to the concrete using non-metallic fixings. 

This material, made of titanium metal joined to a biocompatible substance, is used for hip and knee replacements. (Daculsi-CNRS/Photo Researchers, Inc.)... 

Titanium tetrachloride is a colourless transparent liquid (the boiling point is 136 °C) it is easily decomposed with water forming hydrogen chloride and titanium dioxide. It joins the moisture in air to form white suffocating fumes, which are drops of hydrochloric acid. 

After the maintenance foreman searched for the appropriate titanium impeller and could not find one, he decided to improvise. The maintenance foreman located a stainless steel impeller that was available for other pumps of the same size and manufacturer. He thought the stainless steel would be satisfactory, but would have a shorter life. The mechanics completed the job and the maintenance foreman went to eat an overtime supper at the plant cafeteria where he joined the operating foreman. The maintenance foreman just happened to mention the problems he faced securing the specified impeller and his clever temporary approach to restore the pump. 

Membrel cell — (membrane electrolysis) Electrochemical cell developed by BBC Brown Boveri Ltd, now joined with ASEA AB, to ABB Asea Brown Boveri Ltd) for water electrolysis. A polymeric cation exchange membrane acting as -> solid electrolyte is placed between a catalyst-coated porous graphite plate acting as cathode and a catalyst-coated porous titanium plate acting as anode. 

Attracted to the U.S. market, European investors had also joined the raiders ranks. This is how the Britain-based Hanson Trust managed to acquire SCM. This was a company that had just completed its restructuring but after Sylvachem was sold off by the new owners, it retained only chemical production of titanium dioxide. 

The seam welding technique has successfully joined a variety of aluminum alloys and alloy combinations in thicknesses to 0.125 inch, as well as titanium in thicknesses to 0.056 inch. 

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