Lower boundary in metal explosive welding. Evolution of ideas

Like in any solid state method of metal bonding, a weldability area exists for each pair of explosion welded materials. Establishing the lower boundary of explosive welding is a relevant task because it makes it possible to specify the parameters of the explosive welding process. The existing concepts and models of the lower boundary are comprehensively reviewed, and the evolution of ideas on the subject is described. The axis “average mass of the explosion welded plates” is added to the original representation of the welding areas in the “hydrodynamic” coordinates “collision angle–collision velocity”. Such an approach makes it possible to analyse the bonding process in terms of energy. A new parameter – the pressure deforming pulse – is proposed. This parameter depends on the collision conditions and relates the pressure in the contact area to the time period within which the pressure operates. Thus, it presents the explosive welding lower boundary in the physical coordinates “pressure–time–temperature”.