S. Herbst, L. Jablonik, G. Gerstein, F. Nürnberger, F.-W. Bach
August 8, 2013
Modern light structures increasingly require different alloys or metals to be joined with one another in the form of composite materials . As a result of their different melting temperatures or of the formation of brittle inter-metallic phases, many combinations of metals cannot be produced using thermal methods. One alternative, however, is the use of solid state welding such as explosive or magnetic impulse welding [2; 3]. The examination and analysis of the bonding interfaces is therefore of central importance in the evaluation of the quality of the bond produced. Scanning electron microscopy together with electron probe microanalysis of the characteristic X-rays emitted using EDX and WDX techniques can reveal information regarding the distribution of the metals present within the bonding interface , the presence of inter-metallic phases  and of areas of inadequate bonding. For an accurate evaluation of the characteristic X-rays produced, however, the surface of the specimen must be guaranteed to be both flat and smooth in order to prevent the effects of shadowing and deflection of the primary beam which might otherwise cause erroneous results in the elements present and their distribution . A specimen surface which is not perfectly flat also makes it difficult to focus the electron beam. The simultaneous flat and smooth preparation of metallic composites which have very different strength and hardness properties is very difficult due to the different rates of removal of material during grinding and polishing [7; 8]. In view of this, the following methods of preparation used to produce flat and smooth specimen surfaces on two types of metallic joinings are presented.