Production of stainless steel wire-reinforced aluminium composite sheet by explosive compaction

Abstract

Composite sheet material has been produced by explosively compacting stacks of alternately placed stainless steel wire meshes and aluminium foils. It was found that stacks could be satisfactorily bonded by using an aluminium driver plate which was prevented from bonding to the stack by interposing a polythene sheet. Stacks containing six or seven layers of mesh and having a wire volume fraction of up to 0.24 could be bonded when the driver plate kinetic energy exceeded 120 J cm⁻². It is concluded that the bonding mechanism involves cold pressure welding of the matrix metal by extrusion through the mesh apertures, and the aperture size is a controlling factor in bonding. No evidence was found of strong bonding between the wires and the matrix. In the production of larger sizes of composite sheet, (300 mm×500 mm), blistering and tearing occurred due to the presence of excess air in the stack, a consequence of bowing of the foils by the springy and curved pieces of mesh. This difficulty was overcome by enclosing the stack in a polythene envelope, which was evacuated before detonation of the charge, so that the stack was compressed by atmospheric pressure. Tests have shown that tensile and fatigue properties of the composites compare favourably with other aluminium matrix composites and with high strength aluminium alloys.