Metallographic specimen preparation

Before you rush out to buy a proprietary solution to metallographic polishing and etching, first consult the following book:

Greaves, R. H. & Wrighton, H. 1957 Practical Microscopical Metallography, revised and enlarged 4th edn, London: Chapman & Hall.

We have found, for example, that some of the etches suggested in it for aluminium alloys are far more effective than those suggested in modern texts or by manufacturers of metallography equipment.

If your library doesn’t have a copy, you may be able to find it second-hand using Bookfinder.com.

Increasing the output of X-ray monochromators

My Ph.D. supervisor, Prof. K. H. Jack, FRS, told me, many years ago, about a technique that he called pencilling, which was used in the Cavendish Laboratory in the 1940s to increase the beam intensity from plane monochromators. The technique was apparently devised by Prof. Sir Peter Hirsch, FRS, then one of his fellow Ph.D. students, and is very simple: take the blunt end of a pencil, and rub the surface of the monochromator with it in order to slightly disrupt the crystal lattice and increase the amount of mosaic structure.

See also: Kinematic and Dynamic Diffraction.