Titanium electrical resistivity

Titanium alloyed with niobium exhibits superconductivity, and a lack of electrical resistance below 10 K. Composition ranges from 25 to 50 wt % Ti. These alloys are P-phase alloys having superconducting transitional temperatures at ca 10 K. Thek use is of interest for power generation, propulsion devices, fusion research, and electronic devices (52). 

Titanium siUcides are used in the preparation of abrasion- and heat-resistant refractories. Compositions based on mixtures of Ti Si, TiC, and diamond have been claimed to make wear-resistant cutting-tool tips (157). Titanium siUcide can be used as an electric—resistant material, in electrically conducting ceramics (158), and in pressure-sensitive elastic resistors, the electric resistance of which varies with pressure (159). 

Contact with steel, though less harmful, may accelerate attack on aluminium, but in some natural waters and other special cases aluminium can be protected at the expense of ferrous materials. Stainless steels may increase attack on aluminium, notably in sea-water or marine atmospheres, but the high electrical resistance of the two surface oxide films minimises bimetallic effects in less aggressive environments. Titanium appears to behave in a similar manner to steel. Aluminium-zinc alloys are used as sacrificial anodes for steel structures, usually with trace additions of tin, indium or mercury to enhance dissolution characteristics and render the operating potential more electronegative. 

It is a valve metal and when made anodic in a chloride-containing solution it forms an anodic oxide film of TiOj (rutile form), that thickens with an increase in voltage up to 8-12 V, when localised film breakdown occurs with subsequent pitting. The TiOj film has a high electrical resistivity, and this coupled with the fact that breakdown can occur at the e.m.f. s produced by the transformer rectifiers used in cathodic protection makes it unsuitable for use as an anode material. Nevertheless, it forms a most valuable substrate for platinum, which may be applied to titanium in the form of a thin coating. The composite anode is characterised by the fact that the titanium exposed at discontinuities is protected by the anodically formed dielectric Ti02 film. Platinised titanium therefore provides an economical method of utilising the inertness and electronic conductivity of platinum on a relatively inexpensive, yet inert substrate. 

Titanium disilicide (TiSi2) has very low electrical resistivity and is a promising metallization material.P ] It is deposited by the following reaction ... 

Some types of PEFC employ bipolar steel plates with carefully machined gas grooves to convey a uniform (or desired) gas flow per unit area to the reaction zone. The current of electrons from the tops of the upstands or groove walls into the same area of the reaction zone is influenced by surface films. The same comments apply to titanium flow plates. The optimisation of this situation is, at the same time, the minimisation of a local irreversibility, namely electrical resistance. 

The final steps involve deposition of fhe interconnect metal (Figure4.25, step s). Copper is now the metal-of-choice due to its more desirable electrical resistivity, relative to A1 (1.7 dQ cm v. 2.7 xO cm, respectively) that was exclusively used in earlier ICs. Due to its low resistivity and high density, titanium nitride is an efficient barrier level that prevents surface oxidation of Cu, as well as the interdiffiision of Cu into adjacent layers. To yield the final multilayer IC shown in step t of Figure 4.25, steps p-s are repeated. Indeed, a long complex process that took weeks in the making. 

CDP10-Fb Titanium films are used in decorative coatings as well as wear-resistant tools because of their thermal stability and low electrical resistivity. TiN is produced by CVD from a mixture of TiCL and NH3TiN. 

Titanium boride was used in an epoxy system to induce electrical conductivity. A high filler loading of 46 vol% was selected to study the effect of thermal expansion and contraction on electric conductivity. The filler chosen was composed of rigid particles which cannot form particle-particle coimections other than through direct contact. Figure 15.4 shows the relationships of relative thermal expansion and specific electric resistivity. The resistivity increases slowly with temperature until the contacts between particles of filler are broken which results in a rapid increase in resistance. 

Electric resistance was measured on the membrane which was placed partitioning 3.5 N NaCl solution to its one side and 6.0 N NaOH solution to the other side at 85 °C and the solutions were electrolyzed. The electrolysis was carried out by using a saturated solution of sodium chloride as an anolyte, a titanium lath... 

The addition of mineral fillers such as silica to a resin usually reduces the thermal expansion coefficient considerably. One electrical consequence of thermal expansion in particulate filled resins has been demonstrated by StrUmpler et al. [15]. Epoxy resin filled with the hard filler, titanium diboride, TiBj, show enormous but reversible changes in electrical resistivity (by eight orders of magnitude) on heating from ambient temperature to the cure temperature. This is a consequence of thermal expansion affecting interparticle contacts. 

Titanium metal is a light metal with near half the density of copper (4540 kg.rn" ), exhibits an excellent strength-to-density ratio allowing one to use thinner and lightweight anode plates without sacrificing the mechanical stiffness of the cathode, and has an excellent corrosion resistance to various corrosive environments. The only drawbacks of titanium are its high electrical resistivity (42 pQ.cm) and the high cost of the mill products (e.g., sheet, plate, rods), which can reach 46 US /kg in some cases. 

Mina et al. [19] demonstrated improvements in performance in isotactic polypropylene containing titanium dioxide filler. These include an increase in microhardness and impact properties with an increase in titanium dioxide content in the composite. Also, thermal stability is enhanced and electrical resistivity decreases with an inaease in titanium dioxide content. 

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