USE OF IMPACT TREATMENT FOR STRUCTURAL MODIFICATION AND IMPROVEMENT OF MECHANICAL PROPERTIES OF CuA17 BRONZE OBTAINED BY ELECTRON BEAM ADDITIVE MANUFACTURING

The use of interlayer impact treatment for structural modification and improvement of mechanical characteristics of EBAM CuAl7 bronze samples is investigated using optical microscopy and tensile testing. It has been established that the structural state of the EBAM impact treated samples is determined by such parameters as the impact energy and thickness of the pre-deposited and then treated layers. Higher impact energy levels allow higher effect of grain refining as well as formation of additional annealing twin boundaries to be achieved. Structural modification is achieved by recrystallization of the impact treated pre-deposited metal and provides corresponding improvement in strength characteristics. Criterions for obtaining fully recrystallized grain structures have been formulated. Keywords: additive manufacturing, copper alloy, microstructure, mechanical properties.