Study of the effect of shock wave loading on the structure and properties of bronze alloys BrAZh9-4 and BrAMts9-2

Abstract

Bronze alloys, due to their resistance to mechanical abrasion and high corrosion resistance, are used for the manufacture of machine parts and mechanisms that are subject to friction during operation. We present the results of studying the effect of shock-wave loading on the structure and properties of bronze alloys of grades BrAZh9-4 and BrAMts9-2. Shock-wave loading experiments were carried out by throwing the flyer plate onto cylindrical samples and compressing by a sliding detonation wave. The method of throwing a flyer plate accelerated by the energy of an explosion is often used to determine the spall strength of materials and the method of compression by a sliding detonation wave is used to create a large dynamic pressure inside the material. It is shown that at a throwing speed of a flyer plate of 2.4 km/sec, the impact pressure of the plate with the sample is 15 – 16 GPa, which exceeds the bronze shear strength. Under indicated loading conditions, the hardness of bronze increases by 53 and 25% for BrAZh9-4 and BrAMts9-2, respectively. Studies of the microstructure using scanning electron and optical microscopy revealed multiple cracks and micropores present on the surface of transverse sections forming a zone of spall fracture and areas turning into bands of localized deformation. Moreover, it is shown that when the samples are loaded with a flyer plate in a clip and without it, a greater number of cracks and shear areas are observed. Compression by a sliding detonation wave with a different amount of explosive charge revealed small defects present in the structure at the grain boundaries. The results obtained can be used to developed technologies for modifying and restoring the properties of bronze parts subject to shock-wave destruction.