Aluminium-alloy

This is, currently, by far the most important substrate encountered in the aerospace industry. It is used in sheet form as well as the basis for lightweight honeycomb. 

Unless there are obvious signs of contamination, aluminium honeycomb does not require pretreatment prior to bonding. 

however, any oil or grease contamination be evident, then the affected slice should be immersed in the vapour of a suitable hydrocarbon solvent in a vapour degreasing unit. After immersion, sufficient time should always be allowed for the honeycomb core to drain dry. This is particularly important as liquid solvent held in the corners of the honeycomb cell can be very difficult to detect and must be removed before bonding. 

The initial treatment used in Europe was a chromium conversion coating process using a proprietary product called Iridite. This was a two-component system which contained a blend of highly toxic materials such as chromium salts and ferro- and ferricyanides. 

The Iridite process used a standard cleaning operation (a hot alkaline etch/degrease) followed by a spray-rinse and then immersion in the mixed Iridite 

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The measurements are done at a table with two in X- and Y- direction moveable axes. The measured structures, by an Aluminium-alloy, are situated at the X-axis. The sensor at the Y-axis scans the structure step by step. The position and the electoral signal are measured for every step. A computer controls the movement of the sensor and the data acquisition. 

Presented approach enables an efficient approach to the choice of the proper calibration cur ve, having two terms. Method was tested on big amount of standar ds of brass, bronze and aluminium alloys. 

If Ihe main incoming male contacts are made ol aluminium alloy, which is normally a eompnsilioii of aluminium-magnesium and silicon, they must be provided wiili a coat of bron/e. copper and tin to give it an adequate mechanical hardness and resistance to corrosion. For more details refer to Section 27.2..5. 

Table 30.6 Grades of aluminium alloys for electrical purposes...

Specification for wrought aluminium and aluminium alloys for engineering purposes bars, extruded round tubes and sections 7,13/1991 B.S 1474/1987 6362, 209-1. 2... 

Fig. 11.8. Aluminium alloy quickly necks when it is drown out.

Aluminium alloy is much less good (Fig. 11.8) - it can only be drawn a little before instabilities form. Pure aluminium is not nearly as bad, but is much too soft to use for most applications. 

By far the lightest pressure vessel is that made of CFRR Aluminium alloy and pressure-vessel steel come next. Reinforced concrete or mild steel results in a very heavy vessel. 

Figure 16.6 shows the general yield and fast fracture loci for a pressure-vessel steel and an aluminium alloy. The critical flaw size in the steel is =9 mm that in the aluminium alloy is =1 mm. It is easy to detect flaws of size 9 mm by ultrasonic testing, and pressure-vessel steels can thus be accurately tested non-destructively for safety -vessels with cracks larger than 9 mm would not be passed for service. Raws of 1 mm size cannot be measured so easily or accurately, and thus aluminium is less safe to use. 

Cryogenic -273 to -20°C Copper alloys Austenitic (stainless) steels Aluminium alloys Superconduction Rocket casings, pipework, etc. Liquid O2 or N2 equipment... 

So aluminium alloy is good it resists all the fluids likely to come in contact with it. What about GFRP The strength of GFRP is reduced by up to 20% by continuous immersion in most of the fluids - even salf water - with which it is likely to come into contact but (as we know from fibreglass boats) this drop in strength is not critical, and it occurs without visible corrosion, or loss of section. In fact, GFRP is much more corrosion-resistant, in the normal sense of loss-of-section, than steel. 

Aluminium alloy offers saving of up to 40% in total car weight. The increased unit cost is offset by the lower running cost of the lighter vehicle, and the greater recycling potential of the aluminium. ... 

Fig. 1.5. The aluminium drink can is an innovative product. The body is mode from o single slug of a 3000 series aluminium alloy. The con top is a separate pressing which is fastened to the body by o rolled seam once the can has been filled. There are limits to one-piece construction.

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