Tungsten-Aluminium Alloy : 1970-2008

Photograph by

David Malin FRPS

About this image

Composite scanning electron micrograph of tungsten crystals in a matrix of aluminium. SEMs work by scanning an electron beam across a sample and detecting the scattered electrons. However, the beam can penetrate the surface of a sample depending on the accelerating voltage and the atomic number of the metal. Here three SEMs were created at voltages between 5kV and 30kV. At higher voltages the aluminium matrix appears increasingly transparent. The original images were made in 1970 as monochrome prints. In 2008 they were scanned and combined as different colour layers into a single digital image. RMIT University, Melbourne & Australian Astronomical Observatory, Sydney, New South Wales, Australia