Aluminum alloy composite and method for joining thereof

摘要

The object of the present invention is to strongly join an aluminum alloy part with an FRP prepreg. An object obtained by subjecting an aluminum alloy to a suitable liquid treatment so as to form a surface having large, micron-order irregularities and also fine irregularities with a period of several tens of nanometers, eliminating the presence of sodium ions from the surface and additionally forming a surface film of aluminum oxide, which is thicker than a natural oxide layer, has been found to have a powerful adhesive strength with epoxy-based adhesives. By simultaneously curing an FRP prepreg which uses the same epoxy-based adhesive in the matrix, an integral composite or structure in which FRP and aluminum alloy have been united at a joining strength of unprecedented magnitude is produced.

主权项

1. A method for manufacturing an aluminum alloy composite, in which an aluminum alloy part or parts for serving as a reinforcing member or members in mechanical connection is/are integrally joined with a laminated resin part formed by laminating plurality of prepregs of fiber reinforced plastic; comprising:
a step of shaping an aluminum alloy part or parts by mechanical working from a casting or an intermediate material; a chemical etching step by immersing the shaped aluminum alloy part or parts in a strongly basic aqueous solution; a neutralizing step by immersing the aluminum alloy part or parts in an aqueous solution of an acid after the chemical etching step; an ultrafine etching step by immersing the aluminum alloy part or parts in an aqueous solution containing at least one selected from among hydrazine hydrate, ammonia, and water-soluble amine compounds so as to form on the part an ultrafine irregular surface after the neutralizing step; a step of coating said alloy part or parts with an epoxy-based adhesive; a step of preparing a laminated resin part formed by laminating plurality of prepregs of fiber reinforced plastic containing epoxy resin component; a step of attaching the laminated resin part to the epoxy-based adhesive-coated surface of the aluminum alloy part or parts; and a step of positioning said laminated resin part and the aluminum alloy part or parts and curing the epoxy-based adhesive and the epoxy resin component in the laminated resin part through applying heat and pressure; wherein, with said chemical etching step and ultrafine etching step, surface configuration of the aluminum alloy part or parts is formed such that the surface of the aluminum alloy part or parts has a micron-order surface roughness with a mean peak spacing: RSm of 0.8 to 10 μm and a maximum height: Rz of 0.2 to 5.0 μm and the face with the surface roughness has also an ultrafine irregularity of 10 to 100 nm diameter and equal height or depth; and wherein the epoxy-based adhesive coated onto the aluminum alloy part or parts has a curing temperature property substantially identical with that of the epoxy resin component in the laminated resin part.