The Development of Procedures for the Explosive Weld Cladding of Magnesium Compressor Casings.
BATTELLE COLUMBUS LABS OHIO
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This report describes the experimental procedures, evaluation, and results of the program to demonstrate the feasibility of explosively welding aluminum alloy liners into the blade retaining grooves of EZ33A-T5 magnesium alloy compressor casings. Two groove configurations were investigated, the rectangular and T-shaped configuration. An explosive was developed to meet the requirements of explosive welding the liners into the complex shaped low ductility magnesium casing. A blend of ammonium perchlorate AP - pentaerythritol tetranitrate PETN in the ratio of 75 wo AP-25 wo PETN was found to reliably produce detonation velocities in the range of 2000-3000 msec. in thicknesses of 0.5 to 0.64 cm. Preliminary experiments revealed that a thin layer of aluminum alloy could be explosively welded to EZ33A-T5 magnesium alloy without cracking if 1 the magnesium were heated to a minimum of 150 degrees C prior to welding and 2 the magnesium was well supported by rigid tooling. Groove welding experiments with both flat plates and curved segments revealed that L shaped liners could be successfully welded into each half of a rectangular groove with a minimum of distortion and no corner cracking, if rigid support were provided for the magnesium. The T groove configuration, however, required a slightly greater explosive thickness which resulted in increased deformation and corner cracking in the magnesium.
- Fabrication Metallurgy
- Jet and Gas Turbine Engines