Aluminium mechanical properties

Keywords IN718, ESR, Aluminium, Mechanical properties. Microstructure... 

Many thermoplastics are now accepted as engineering materials and some are distinguished by the loose description engineering plastics. The term probably originated as a classiflcation distinguishing those that could be substituted satisfactorily for metals such as aluminium in small devices and structures from those with inadequate mechanical properties. This demarcation is clearly artificial because the properties on which it is based are very sensitive to the ambient temperature, so that a thermoplastic might be a satisfactory substitute for a metal at a particular temperature and an unsatisfactory substitute at a different one. 

ALUMINIUM AND ALUMI UM ALLOYS Table 4.8 Mechanical propertied of aluminium... 

The physical properties of the newer alloys have been well documented (see bibliography). Essentially, they lie between those of Alloy 5 (Alloy B) and of Alzen 305 in Table 4.31, broadly in relation to their aluminium content. The mechanical properties vary considerably according to the method... 

Heat treatment after plating Heat treatment may be necessary after plating to improve the adhesion of coatings on aluminium and its alloys when certain processes, e.g. the Vogt process, are used, or to minimise hydrogen embrittlement of steel parts. Care is needed since heating may distort the part and impair the mechanical properties of the substrate. 

At present, the most promising fillers are those with 1/d P 1, i.e. fibers and flaky fillers that make it possible to reduce filler concentration in a composite and, thus, facilitate the processing and improve physical-mechanical properties [17]. Besides cut carbon fibers, carbon fibers coated with a layer of Ni that have higher conductivity have been developed (American cyanamid) [14]. Glass fibers with a layer of aluminium (MB Associates, Lundy Electronics) [16] are in production. 

The low-temperature thermal conductivity of different materials may differ by many orders of magnitude (see Fig. 3.16). Moreover, the thermal conductivity of a single material, as we have seen, may heavily change because of impurities or defects (see Section 11.4). In cryogenic applications, the choice of a material obviously depends not only on its thermal conductivity but also on other characteristics of the material, such as the specific heat, the thermal contraction and the electrical and mechanical properties [1], For a good thermal conductivity, Cu, Ag and A1 (above IK) are the best metals. Anyway, they all are quite soft especially if annealed. In case of high-purity aluminium [2] and copper (see Section 11.4.3), the thermal conductivities are k 10 T [W/cm K] and k T [W/cm K], respectively. 

Aluminium alloys are very seldom used below their transition temperatures ( 1.2K) [12], but find application at temperatures above 4K [13] where the thermal conductivity is lower than that of the pure metal [14], and the mechanical characteristics are much better. In particular, because of their lightness, good mechanical properties and high thermal conductivity [15-17], aluminium alloys are often used in the realization of structures and shields in space applications [18-20],... 

Ryder, C.. Vidoz, A., Crossman, F., Camahorl, J. (1970), Mechanical properties of nitrided boron-aluminium composites, J. Composite Mater. 4, 264-272. 

An investigation is reported of the dynamic mechanical response of aluminium silicate filled closed cell microcellular ethylene-octene copolymer (Engage) vulcanisates. The effect of blowing agent, frequency and temperature on dynamic mechanical properties is studied, and the strain-dependent dynamic mechanical properties of microcellular Engage are also investigated. 25 refs. INDIA... 

The malleability and ductility of tantalum are destroyed by the presence of even traces of foreign bodies 0-1 per cent, of carbon, for instance, renders the material brittle. Older laboratory reactions which gave rise to more or less pure tantalum deficient in mechanical properties consisted in reducing tantalum pentoxide with mixed metal (see p. 134) or with carbon in the electric furnace 3 the equilibrium conditions of the reduction of tantalum pentoxide by carbon at high temperatures have been investigated by Slade and Higson.4 The thermite process yields an alloy of tantalum and aluminium.5... 

The carbides and nitrides are well known for their hardness and strength, and this section will briefly compare a number of these properties with those of the pure metals. Concentration will be placed here on the first row compounds, since these constitute a complete series, and Mo and W, since these are the most commonly studied metals. As will be shown, the physical and mechanical properties of carbides and nitrides resemble those of ceramics not those of metals. Comparisons will be made with boron carbide (B4C), silicon carbide (SiC), aluminium nitride (AIN), silicon nitride (Si3N4), aluminium oxide (A1203), and diamond, as representative ceramic materials. 

Tsui, T.Y., Oliver, W.C. and Pharr, G.M. (1996), Influence of stress on the measurement of mechanical properties using nanoindentation Part I. Experimental studies in an aluminium alloy , Journal of Materials Research, 11, 752-759. 

Sensing hydrogen in molten aluminium Because of the detrimental effect dissolved hydrogen can have on the mechanical properties of many metals it is monitored in metallurgical processing. For this the requirement is for a proton conductor and suitable ceramics have been identified. 

Sensing sodium The /1-aluminas (see Section 4.5.3) can be successfully exploited as a sodium sensor. Sodium is widely used in the metallurgical industry, for example for removing arsenic and antimony from zinc and lead, for removing the same two elements and oxygen from copper, and phosphorus from iron. It is also added to aluminium-silicon alloys to control microstructure and, in consequence, mechanical properties. 

M. Wladyka-Przybylak and H. Rydarowski, Flammability and mechanical properties of PP modified by nanoclay compounds and aluminium hydroxide flame retardant, in Proceedings of the 19th BCC Conference on Flame Retardancy, M. Lewin (Ed.), Business Communications Co Editions, Norwalk, CT, 2008. 

In modern technical alloys, which almost all consist of a large number of components, the presence or absence of traces of some elements plays an extraordinarily great role in determining the mechanical properties. We have previously seen how it is just in the metals that such a great influence of traces can become manifest. The individual, typically chemical properties of the admixed elements usually play only a minor role in this (compare on the other hand de-oxidation of steel by aluminium or sodium). 

This material has excellent mechanical properties and is used extensively as weather resistant coating for aluminium and various outdoor applications. The piezoelectrical properties of the material have been exploited in a range of electronic applications [220]. 

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