Identification of planar defects by etch pits formed on the mantle surface of cylindrical single crystals

The formation of etch pits directly on the mantle surface of cylindrical single crystals rather than on flat surfaces, as it is usually performed, allows easier and more accurate determination of the crystal orientation. The application of this technique to tungsten single crystals subjected to compression tests at low temperature allows an easy identification of the twinning systems. This technique is well adapted to single crystals subjected to mechanical tests mainly because it does not require the preparation of flat surfaces before or after the test to reveal etch pits. Producing flat surfaces could induce stress within the crystals that in turn could activate slip or twinning mechanisms and would, therefore, give wrong results.