Titanium Development Association

H. R. Phelps and C. Harberg, Proceedings of Titanium Development Association Conference, San Diego, Calif., 1994. 

Source R. Pishko, T. Yu, and G. Kuhiman, Precision Forging of Titanium Alloy, in Jilanium 1966Products and AppHcaVons, Titanium Development Association, 1987, p401... 

F.H. Frees, D. Eylon, and H.B. Bomberger, Ed., Titanium Tkchnolo Present Status and Future TYends, Titanium Development Association, 1985... 

R.W. Schutz and J.S.Grauman, Selection of Titanium Alloys for Concentrated Seawater, NaCl and MgCb Brines, Titanium 1986—Titanium Products and Applications, proceedings of the Technical Program from the 1986 International Conference, San Francisco, CA, Titanium Development Association, 1986... 

Examples are tViggin Alloys 100, Henry Wiggin Co. Ltd., Hereford Copper in Chemical Plant, Copper Development Association, London (1960) Corrosion Resistance of Stainless Steel, Publication 112/1, Firth Vickers Stainless Steel Ltd., Sheffield Corrosion Resistance of Titanium, Imperial Metals Industries (Kynoch) Ltd., Birmingham... 

Iron is associated with silica sand, usually as a light surface stain on the grains. Amber glass develops ionic color centers or complexes of Fe-S-C added to the batch as iron sulfide and powdered anthracite. Although the Fe content be four or five times that shown in the example in Table I, it appears to be bound in the complex so that no greater extraction occurs with the S and C. Titanium is associated with sand as... 

G.W. Kuhiman, et a/., Mechanical Property Tailoring Titanium Alloys for Jet Engine Applications, Proc. 1986 Int. Conf. Titanium Products and Applications, Titanitim Development Association, 1987, p 122-153... 

Selective catalytic reduction (SCR) is cmrently the most developed and widely applied FGT technology. In the SCR process, ammonia is used as a reducing agent to convert NO, to nitrogen in the presence of a catalyst in a converter upstream of the air heater. The catalyst is usually a mixture of titanium dioxide, vanadium pentoxide, and hmgsten trioxide. SCR can remove 60-90% of NO, from flue gases. Unfortunately, the process is very expensive (US 40- 80/kilowatt), and the associated ammonia injection results in an ammonia slip stream in the exhaust. In addition, there are safety and environmental concerns associated with anhydrous ammonia storage. 

Titanium is a reasonably common element which has been known for over 170 years. The average titanium content of the earth s crust is 0.63% by weight, which makes it the ninth most abundant element in the earth s crust, 20 times more abundant than carbon, and only outranked by oxygen, silicon, aluminum, iron, magnesium, calcium, sodium and potassium. It is only really in this century that elemental titanium has developed any industrial potential, partly because of difficulties associated with its refinement. 

Titanium is a relatively common element comprising 0.63% of the earth s crust, making it the ninth most abundant element and the second most abundant transition element (after iron). Despite this abundance, it is only during the latter part of the twentieth century that the element has developed any industrial potential, which is due largely to the difficulties associated with its refinement. 

Aluminum, boron, carbon, iron, nitrogen, oxygen, phosphorus, sulfur and titanium are the common impurities in the SoG-Si feedstock. Arsenic and antimony are frequently used as doping agents. Transition metals (Co, Cu, Cr, Fe, Mn, Mo, Ni, V, W, and Zr), alkali and alkali-earth impurities (Li, Mg, and Na), as well as Bi, Ga, Ge, In, Pb, Sn, Te, and Zn may appear in the SoG-Si feedstock. A thermochemical database that covers these elements has recently been developed at SINTEF Materials and Chemistry, which has been designed for use within the composition space associated with the SoG-Si materials. All the binary and several critical ternary subsystems have been assessed and calculated results have been validated with the reliable experimental data in the literature. The database can be regarded as the state-of-art equilibrium relations in the Si-based multicomponent system. 

The feasibility of FSW of titanium was first demonstrated prior to 1997 at which time a TWI group sponsored project (GSP 5689) was instituted to further the development of FSW in titanium alloys [1]. Proof- of-concept and initial development was performed mainly on Ti-6A1-4V. While some reports of FSW of titanium are available in conference proceedings or have been presented at conferences [2-6] no papers in the archival literature have been published on the subject. Conceptually, FSW of titanium is attractive because it may mitigate some problems associated with fusion welding of titanium alloys. For example, because peak temperatures in FSW are necessarily lower than those encountered in fusion welds, problems such as grain growth in the HAZ and embrittlement due to contamination by interstitial elements (0, N, C) uptake may be reduced. 

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