This paper presents an experiment conducted in Explosia, a.s., Pardubice. A bimetal prepared of AZ 31 Mg alloy - CrNi austenitic steel was tested in various conditions, and consequently its quality was assessed. Focus was particularly on the impact of atmosphere and vacuum on the interface character of the metals (bimetals) prepared by explosion. Parallel placement of the materials being welded was used for welding in both vacuum and air atmosphere. Welding sets were designed and manufactured. The welding parameters and conditions were set up utilising the available computational means, and then verified by simulation in ANSYS engineering-scientific program. Used was Semtex S 35, a loose explosive, as well as Startline 12, an initiation explosive. Bimetal was fabricated in the air atmosphere at the detonation speed 2613 m.s-1 and in vacuum at the detonation speed 2597 m.s-1. Quality of bimetals was assessed by optical microscopy, measuring deformations by a 3D scanner, measuring microhardness and also by EDX microanalysis.

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Two important parameters reflect in the quality of the interface of two explosively welded metal plates – impact velocity and collision angle. Both parameters can be determined from the knowledge of velocity history of the accelerated surface. A suitable measurement methodology that would allow in‐situ determination of the course of acceleration at a technological scale experiments is however not yet available. One of the emerging options enabling such measurements is Photonic Doppler Velocimetry (PDV). This paper focuses on the issues observed during measurement of metal plate acceleration in explosive welding using this technique. A well‐known combination in which copper plate is accelerated by detonation and welded to a steel baseplate was chosen for small scale experiments. The methodology was further employed at a large scale technological tests were two different steel plates were joined by detonation. The PDV proved to be successful in determination of the entire velocity history and provides unprecedented insight into the welding process. The knowledge of the velocity time history enables optimization of the impact velocity and collision angle without having to modify the explosive composition. A methodology of velocity measurement of the entire velocity profile of accelerated plate and its collision velocity during metal welding was developed. In addition, we are proposing a new way of optimizing welding parameters based on the exact velocity and thus a collision angle calculation.