Aluminium machinability

By treatment with anhydrous aluminium chloride (Holmes and Beeman, 1934). Ordinary commercial, water-white benzene contains about 0 05 per cent, of thiophene. It is first dried with anhydrous calcium chloride. One litre of the dry crude benzene is shaken vigorously (preferably in a mechanical shaking machine) with 12 g. of anhydrous aluminium chloride for half an hour the temperature should preferably be 25-35°. The benzene is then decanted from the red liquid formed, washed with 10 per cent, sodium hydroxide solution (to remove soluble sulphur compounds), then with water, and finally dried over anhydrous calcium chloride. It is then distilled and the fraction, b.p. 79-5-80-5°, is collected. The latter is again vigorously shaken with 24 g. of anhydrous aluminium chloride for 30 minutes, decanted from the red liquid, washed with 10 per cent, sodium hydroxide solution, water, dried, and distilled. The resulting benzene is free from thiophene. 

Fig. 4.10. The two main types of dear-ice machine. In the top one, the ice grows on the outside of a set of aluminium cold fingers. In the bottom one, the cubes grow in aluminium troys. Cubes ore removed when they ore big enough by stopping the flow of refrigerant and heating the aluminium electrically. This melts the surface of the ice so that it con fall away from the metal (remember that the easiest way to take the wrapper off on ice lolly is to worm the outside with your hands for a minutel)...

Steel with up to 0 075 mm thick aluminium coatings can be gas-cut by both hand and machine methods, and welded, without removal of the aluminium. No fume problems arise in welding aluminium-coated material in practice, however, it is usual to leave the edges bare and to spray the joint with aluminium after welding. 

For electronic micrographs, samples were taken from fresh beads and 72 hour beads from the ICR column. The samples were dipped into liquid nitrogen for 10 minutes, then freeze dried for 7 horns (EMITECH, model IK750, Cambridge, UK). The sample was fixed on an aluminium stub and coated with gold-palladium by a Polaron machine model SD515... 

A quantity sufficient to carry out the required tests, generally in duplicate, are filled into the containers. Most substances for which there are no concerns for either toxicity or stability are filled by weighing the appropriate quantity into antibiotic vials in a horizontal laminar flow work station. These operations are carried out in a self-contained cubicle to avoid cross-contamination. The vials are then closed with butyl rubber stoppers and sealed with an aluminium crimp seal using an automatic crimping and labelling machine. 

Figure 2.8 shows the general arrangement of the instrument with 100 optical cuvettes radially dispersed around the vertical axis of the reaction rotor. The optical components of the dual-channel monochromator are rigidly mounted within a machined aluminium housing (which is not shown in the diagram), and the housing itself is sohdly fixed to the top of the rotor. 

Fig. 4. The nominal breaking stress (Amsier testing machine) of aluminium alloy/epoxy single lap joints as a function of the hydroxyl content of the epoxy raised to the two-thirds power51 (Reprinted from Ref. 51, p.307, by courtesy of Society of Chemical Industry)...

There are a number of well-established systems for the aseptic packaging of liquids. Notable among these are those packs constructed, box form, in situ on the filling line from a cardboard, aluminium, plastic laminate sheet, such as TetraPak or Combi-box. In the TetraPak system, the packing material enters the filling machine from a feed roll the sheet contact surface is sterilised with warm hydrogen peroxide solution it is formed into a tube, and its lower end is heat-sealed across the width the tube is filled, sealed at the upper end, cut and then folded into a box shape. This produces a continuous output of filled cartons with premium utilisation of bulk storage capacity. 

The effect of silanes on the bond strength of two epoxide adhesives to glass is shown in Table 13. The test mode was that of Sandwich Butt Tensile in which a glass disc was bonded between two aluminium specimens in the form of a sandwich, and the resulting composite specimen broken on an Instron Universal Test Machine. Clearly in such a composite test specimen, alignment is important and there are many potential sites and modes of failure. 

Thacker [24] reported the design of a miniature flow fluorimeter for liquid chromatography. The body of the fluorimeter was machined from a block of aluminium and contained a low-pressure mercury lamp, an excitation filter, a quartz flow cell, an emission filter, a photomultiplier tube and a photoconducter in order to compensate for fluctuations in lamp intensity. Fluorescence was examined at a direction perpendicular to that of the excitation light. The cell was small enough for it to be attached directly to the end of the column with a minimum dead volume. 

Since the early days of machine made paper in the first half of the nineteenth century, the most widely applied method of Internal sizing has been the use of naturally occurring resinous materials ("rosins") in conjunction with an aluminium salt, usually aluminium sulphate (called "alum" by paper-makers). Various forms of rosin sizes (rosin soaps, rosin emulsions, fortified rosins) have been developed over the years to improve the process, but these variants still involve the use of alum as a means of ensuring that fibres retain a layer of size. 

Consider the main features of the process of dissolution of some transition metals in liquid aluminium as an example.169,303,304"30S Cylindrical specimens of a transition metal, 11.28 0.01mm diameter and 5-6 mm high, were machined from 12-13 mm diameter rods produced by arc melting the metal under investigation. The disc surface was then ground flat and polished mechanically. 

A number of commercial machines are available and cuvettes may be bought or constructed from disposable spectrophotometer cuvettes into which aluminium electrodes are glued. They can be sterilised with 70% ethanol and then washed with sterile PBS. (This is also true for the disposable commercial cuvettes.) The same apparatus can also be used for cell fusion (electrofusion) (see 13.7.3 and Glassy, 1988). 

---