AbstractThe work reported here is concerned with establishing the 'welding window' for half hard copper welded to half hard copper. To allow this window to be fully explored a 63.5 mm gas gun has been designed and developed, as a simulation of explosive welding. The gun can fire a flyer plate at velocities up to 1 km/s using helium as the driving gas for the higher velocity and air for the lower velocity region. The driving pressure is determined by use of scribed bursting discs which have been studied to establish their bursting pressure characteristics and modes of failure. An improved velocity measuring system using a Schmitt circuit with thin wires as switching elements has been developed.
Extensive experimental data on the welding of 1.58 mm and 3.17 mm thick flyer plate to 10 mm thick parent plate are reported. The data includes micrographic examination of the weld interfaces from which, when a wavy configuration occurred, the amplitude, wavelength and character of the wavy interface were obtained. The strengths of the welds achieved, which were determined by a side shear test, are reported.
A welding window has been established within which welds of adequate integrity and without cracks can be obtained, although significant thinning of the flyer plate takes place in some regions of the window. The varying nature of the weld interface is illustrated within the window. The data are presented in the p/B and w/B plane and they are compared with experimental data given by other workers for the same material combination. The boundaries of the window and the transition from straight to wavy interface are compared with theoretical predictions.
Suggestions are made for a more ‘conservative’ window for use in practice.
|Date of Award
|Bernard Crossland (Supervisor)