Observations on machining damage in beryllium

Various experimental activities are described which were introduced into the machining procedure to produce a test rod, 4 mm x 3 mm section, from isostatically compacted flake derived high purity beryllium powder. A 3-point bend test was used to investigate both the level of machining damage induced by the different machining techniques and also the ameliorative effects of etching and annealing procedures on damaged surfaces. Specific debilitating effects, eg deburring, were studied by optical and electron microscopy. An alternative process was evolved to produce parts which could not be treated by standard etching and annealing techniques. (author)