Study On Explosive Welding Of Aluminum Steel And Its Harmful Effects Under Different Vacuum Conditions

Explosive welding technology is a composite material processing technology that uses explosive energy to drive the cladding and base layer to collide at high speed and realize metallurgical combination.Compared with other welding technologies,explosive welding has many advantages such as low production cost,high welding efficiency and high bonding quality.Metal composite materials produced by explosive welding have been widely used in many fields such as chemical industry,aerospace,metallurgy and electric power.However,due to the low utilization rate of explosive energy in the explosive welding process,the amount of explosive used for single welding is large and the explosive is exposed.When the explosive explodes,most of the energy is transmitted to the surrounding environment in the form of shock wave,and the harmful effects produced have a great impact on the surrounding environment of the welding site,which seriously limits the development of the industry.In order to reduce the harmful effects in the process of explosive welding,relevant enterprises have begun to carry out explosive welding in vacuum closed structures,but the theoretical research on the impact of vacuum environment on explosive welding of composite plates and harmful effects is rare.In order to study the influence of vacuum degree on explosive welding composite bonding interface and harmful effects of explosive welding,the explosive welding experiments of 6061 aluminum alloy and Q235 steel under different vacuum degrees were carried out in a 5 kg equivalent vacuum spherical explosive container.The microscopic morphology of the composite plate and the harmful effects such as shock wave,vibration and noise generated during explosive welding were studied and discussed.The relevant conclusions are as follows:(1)The higher the vacuum in the explosion container,the smaller the peak overpressure of the shock wave generated by explosive welding.The peak overpressure of the shock wave under the vacuum of-90 k Pa is 65.70% lower than that of 0 k Pa.The change trend of specific impulse of shock wave with vacuum degree is the same as that of overpressure peak of shock wave,and decreases with the increase of vacuum degree in explosion vessel.The numerical calculation results show that the top of the explosion container will bear the secondary impact effect.When designing the spherical explosive processing equipment,the protective measures on the top of the equipment should be strengthened.(2)The peak value of vibration velocity at the top of the vessel and at the ground measuring point decreases gradually with the increase of the vacuum pressure in the vessel.The peak value of vibration velocity at the vessel measuring point under-90 k Pa vacuum pressure decreases by about 74.46% compared with that at 0 k Pa,and the peak value of vibration velocity at the ground measuring point decreases by about 29.45%.The dominant frequency band of the vertical vibration signal of the measuring point on the top of the vessel is mainly distributed between 200 and 400 Hz.Its overall frequency distribution characteristics are not significantly related to the size of the explosion load,but only to the stiffness distribution and mass distribution of the vessel’s own structure.The influence of the prestress caused by the pressure difference inside and outside the explosion vessel on the vessel structure can be ignored.With the improvement of the vacuum degree in the explosion container,the maximum noise sound pressure level generated by explosion welding gradually decreases.The maximum noise sound pressure level in the container when the vacuum degree is 0,-30,-60 and-90 k Pa is 114.09,105.59,96.17 and 85.05 d B respectively.When the vacuum pressure in the container is – 90 k Pa,the maximum noise sound pressure level is 29.04 d B lower than that in the atmospheric pressure environment.(3)The 6061/Q235 explosive welded composite plate has good bonding quality under two vacuum degrees of 0 k Pa and-90 k Pa.The bonding interface is mainly flat and straight,and some areas are large wave bonding,without obvious defects such as cracks.The melting zone is mainly composed of Al Fe intermetallics.Due to the small area of the plate,the physical and chemical properties of the two materials of the base clad plate are quite different,and the characteristics of the bonding interface and of 6061/Q235 explosive welded composite plate under two groups of environments are not obvious.Figure[42] Table[13] Reference[84]...