Structural alloys

These advantageous mechanical properties result in an excellent wear resistance which - in combination with an excellent corrosion resistance in various environments - makes the Tribaloys very appealing for applications in a broad range of temperatures and environments. 

---

Pure aluminium lacks mechanical strength but has higher resistance to corrosion than its alloys. The main structural alloys used are the Duralumin (Dural) range of aluminium-copper... 

Pure mercury does not easily wet steels and certain other structural alloys, thus it is an unwetted case. It causes the direct transition from liquid phase to film boiling heat transfer. The phenomenon has also, on occasion, been observed with alkali metals (Noyes and Lurie, 1966 Avksentyuk and Mamontova, 1973). Figure 2.42 shows experimental heat transfer results for pool boiling of pure mercury on... 

Strouhal number, 11 747, 756, 757 Structural adhesives, 1 534-545 Structural alloys, of titanium, 24 840 Structural analysis, in fine art... 

Synthesis of nano-structured alloys by the inert gas evaporation technique A precursor material, either a single metal or a compound, is evaporated at low temperature, producing atom clusters through homogeneous condensation via collisions with gas atoms in the proximity of a cold collection surface. To avoid cluster coalescence, the clusters are removed from the deposition region by natural gas convection or forced gas flow. A similar technique is sputtering (ejection of atoms or clusters by an accelerated focused beam of an inert gas, see 6.9.3). 

Synthesis of nano-structured alloys via mechanical deformation... 

Allotrope different forms of an element characterized by different structures Alloy a mixture of two or more metals, for example, zinc + copper = brass Alpha Decay nuclear process in which an alpha particle is emitted by the nucleus... 

It is also worth noting that laser electrodispersion can produce nano-structured alloy coatings and composite coatings composed of particles of different metals. For these purposes, alloyed targets are used and targets made of different materials are alternately irradiated. 

Y. Zhang, Y. Tsushio, H. Enoki, E. Akiba, The hydrogen absorption-desorption performances of Mg-Co-X ternary alloys with BCC structure, . /. Alloys Compd. 393 (2005) 185-193. 

Structural Alloys Handbook, 1982 Suppl. Vol., BatteUe Memorial Institute, Columbus, Ohio, 1982. 

Lithium forms structural alloys with both aluminum and magnesium. Mg-Li alloys have the highest strength-to-weight ratio of all structural materials. Li is used as a degasser to scavenge oxygen in the production of steel and of copper. It is also used as the anode (positive terminal) of some batteries. 

Galvanic series are well known to many. These listings of corrosion potentials for materials (generally structural alloys) in a given environment are often... 

Nonmetallic conductors and corrosion products. Carbon brick in vessels is strongly cathodic to the common structural alloys. Impervious graphite, especially in heat-exchangers, is cathodic to structural steel. Carbon-filled polymers can act as active cathodes. Some oxides or sulfates are conductors, such as mill scale (magnetite Fe304), iron sulfides on steel, lead sulfate on lead can act as effective cathodes with an important area to that of the anodes. Very frequently, the pores of the conductive film are the preferable anodic sites that leads to localized corrosion (pitting).5... 

Lithium-Structure Compatibility. One of the critical chemistry problems of HYLIFE is the compatibility of structural alloys with the molten liquid of the jet array. Two candidate liquid metals are lithium and Pbg3Lij 7. High-Z metal (such as lead from target debris) will enter the liquid metal and may affect the compatibility. The structural alloy selected in the HYLIFE study is Cr-1 Mo, a ferritic steel. The carbides usually present in this steel are M3C (cementite) and M2C, where M is primarily Fe. Both of these carbides are unstable in lithium. M3C is usually present as platelets within pearlite, the eutectoid structure in pearlitic steel. The most common microstructure for the 2 4 Cr-1 Mo steel is large grains of ferrite with small islands of pearlite. M2C is present as a fine spray of precipitate within large ferrite grains. Lithium... 

Magnesiiun Dolomite ([Mg,Ca]C03) Electrolysis of fused MgCb (obtained from brines) Lightweight structures (alloys) Sacrificial electrodes Flares, pyrotechnics, incendiary bombs... 

It should be noted that the work function of structural alloys is always less than the work function of the isolated component metals. For instance, the work functions of B and La are 4.5 and 3.3 eV, respectively - much higher than LaBe. The mechanisms... 

Nowadays, the application of the ultrasonic treatment ensures the reliable reproduction of the nondendritic structure in ingots (Figure 25) from the majority of aluminum structural alloys of the Al-Cu-Mg-Mn and Al-Zn-Mg-Cu systems (ingots of 65 to 1200 mm in diameter) and from magnesium alloys (ingots to 270 mm in diameter) containing modifying additions of Zr. 

Magnesium occurs widely in carbonate ores, but most Mg comes from salt brines and from the sea (Figure 22-5). Sea water is 0.13% Mg by mass. Because of its low density (1.74 g/cm ), Mg is used in lightweight structural alloys for such items as automobile and aircraft parts. 

When chromium is alloyed with iron, tough, hard steels or steels that are corrosion-resistant are formed. Chromium is also alloyed with other transition metals to produce structural alloys for use in jet engines that must withstand high temperatures. A self-protective metal, chromium is often plated onto other materials to protect them from corrosion. 

Besides the fundamental work cited above, IPMS in Kiev did carry out some research work in the field of Cr-Re structural alloys, unfortunately the works were stopped in the mid-80 s, with the clear statement that Re alloying strongly decreased the DBTT of Cr-Re alloys, but without providing precise data neither on their mechanical, chemical nor thermal properties. The joint research projects between IPMS, UPC and EADS that this document partly summarizes aims at designing a suitable manufacturing process for these alloys and characterize the relevant properties for EADS related applications. 

---