Uniaxial tensile fracture of stainless steel-aluminium bi-metals

The mechanical behaviour of aluminium 1A30-stainless steel 1Cr18Ni9Ti bi-metals, made by the explosive welding method, is investigated under uniaxial tension conditions. The mechanical parameters of the bi-metal calculated using the mixture rule theory under uniaxial tension conditions are compared with measured parameters. It is found that the mixture rule theory is suitable for the calculation of the mechanical parameters except for ultimate tensile strength. Experimental data show that yield stress and ultimate tensile strength have an exponential relationship with the relative thickness ratio of stainless steel, respectively. A mathematical model is introduced to describe the relationships of yield stress and ultimate tensile strength to the relative thickness ratio of stainless steel. It is also found that elastic modulus, hardening coefficient, and hardening exponent basically have a linear relationship with the absolute thickness ratio of stainless steel, respectively. All the relationships show a monotonically increasing tendency. Fracture behaviour under uniaxial tensile conditions mainly take the form of fracture on the stainless steel side of the bi-metal and detachment in the interface.