Influence of Heat Treatment on the Structure and Properties of Explosively Welded Composite Ad1+cr20ni80+ad1

The article presents the results of studying the transformation of the structure and phase composition of the aluminum layer during heating of a three-layer composite of aluminum AD1 + Cr20Ni80 alloy + aluminum AD1 above the eutectic transformation temperature. It is shown that it is possible to form layers with a structure strengthened by intermetallics from row to matrix, with a hardness of 6 to 8 GPa in the composition of layered metal-intermetallic composites obtained by explosion welding with subsequent rolling. It is established that the growth of the diffusion zone during HT occurs both towards aluminum AD1 and towards the Cr20Ni80 alloy. It is revealed that during HT according to the contact melting mode, a «row» structure of the eutectic type with alternating layers of intermetallics CrAl7 and NiAl3 is formed in the initial aluminum layer, the size of which increases with increasing HT time. In the transition zone with a thickness of ≈ 3 μm between the Cr20Ni80 alloy and the layer with a row structure, there is a smooth decrease in the Al content and an increase in the concentration of Cr and Ni with subsequent equalization of the chemical composition in the Cr20Ni80 alloy layer. At a temperature above the melting point of Al during the HT, which ensures the liquid-phase interaction of its melt with the Cr20Ni80 alloy, the «row» structure is absent, and the transformed Al layer is a mixture of a complex phase composition NiAl3 + Cr (Al) + Al (Cr). The thickness of the transition zone between the Cr20Ni80 alloy and the transformed Al layer is ≈ 2 μm.