A COMPUTER SIMULATION STUDY OF CONTACT HARDENING OF ALUMINUM INTERLAYER DURING TENSILE STRESSING OF MAGNESIUM-ALUMINUM COMPOSITES

Abstract

Fusion welding of magnesium and aluminum results in the formation of brittle intermetallic compounds, which significantly reduce the performance of the structures. Therefore, explosion-welded magnesium-aluminum adapters of various designs are commonly used. Two types of joints are most commonly used: 1) the MA2-1–AD1–AMg6 composite, suitable for operation at temperatures ranging from –196 to +100 °C, preventing overheating of the AD1–MA2-1 interface during arc welding; 2) the four-layer MA2-1–VT1-0–AD1–AMg6 composite, designed for operation in the temperature range from –196 to +500 °C. The strength of such joints in the direction normal to the interface between the layers is determined by the properties of the weakest of the constituent materials, which is usually the aluminum interlayer, which acts as a ductility buffer and diffusion barrier. As the interlayer thickness decreases (usually characterized by the relative thickness χ = h/d, where h is the interlayer thickness and d is the diameter of the test specimen), the contact hardening effect begins to manifest itself. A graph-analytical method was previously developed for calculating the strength of composites with soft interlayers, providing results acceptable for practical use. The development of the finite element method and the creation of software packages based on it, such as SIMULIA/ABAQUS, has made it possible to more accurately model the behavior of various processes—from hydrodynamic flows of molten metals and temperature fields in heated slabs for rolling to the deformation of composite materials with layers that differ significantly in strength characteristics.