УДК 621.9.011 © Tomasz Babul INFLUENCE OF ACCELERATION WAY ON POWDER VELOCITY DURING DETONATION SPRAYING The paper report discusses some significant aspects of formation of coatings deposited by the high velocity detonation method, especially the morphology of the transition zone between the coating and the substrate. <...> The influence is presented of selected technological parameters on the variation of the stream velocity, formed by the energy of detonative combustion of gaseous explosive mixtures. <...> Measurements of velocity of the spray velocity were carried out for paths of powder acceleration within the range of 110 mm to 710 mm. For the purpose of this study, a work stand based on pyrotechnical technique was adopted. <...> The results of measurements of the velocity of NiCrBSi powder are presented. <...> A discussion and an illustration are given of the effect of particle velocity on phenomena taking place in the transition zone between the coating and the substrate. <...> Despite the fact that they allow the attaining of collision velocities reaching 2500 m/s, while temperatures of the elements being joined are close to ambient [1, 2], they have not found broad application in the formation of the superficial layer, mainly because of the need to protect the treated component from the possibility of occurrence of geometric changes (deformation). <...> In order to eliminate the above mentioned unfavourable phenomenon, while attaining collision velocities within the limits of 600 – 1000 m/s, the investigations steered in the direction of utilization of the energy of combustion of gaseous explosive mixtures with the maximum possible velocity, i.e. by detonation. <...> Initial tests were undertaken in the early fifties of the bygone century, while the first patent relative to the detonating equipment was registered in 1955. <...> STAND FOR DETONATION SPRAY DEPOSITION In this work valveless equipment was utilized which enables the acceleration of powder particles to velocities exceeding severalfold the speed of sound. <...> As opposed to other types of equipment, the designed and manufactured test apparatus is based on the principle of continuous, valveless system of introducing the working gases to the incinerating chamber. <...> This allows the carrying out of the coating spraying process, using different types of inflammable gases, such as propane-butane, acetylene and hydrogen. <...> This design enables the accomplishment of technological processes not only with various process frequencies, explosive gas mix compositions and types of powders, but also a variation of the length of powder acceleration, as well as the carrying <...>