A3003/SUS304L two-layer clad materials were produced using the vacuum roll bonding, and subjected to heat treatment at a holding temperature of 500°C with various holding times. Bond strength and the bond interface structure of the clad material were investigated, and were compared with those as produced. In the range of heat treatment conditions with up to 60 min, the bond strength of the heat-treated material was found to exceed that as produced.
Heat treatment at 500°C induced the mutual diffusion of the structural components of A3003 and SUS304L through an amorphous layer at the clad material bond interface, thus forming a new structure. That is, the patch structure formed at the bond interface of the as produced was changed into a feather structure due to 500°C×10 min heat treatment, formed through the erosion of A3003 crystals. In the case of 500°C×30 min heat treatment, a fine columnar structure was precipitated at the interface between the amorphous layer and the SUS304L.
Accordingly, the bond strength is considered to have increased by the heat treatment at 500°C.
