Formation of a superplastic nanostructured aluminum matrix for a metal matrix composite reinforced with continuous fibers

Abstract

The work examines the microstructure of the 1565ch alloy of the Al-Mg system after combined treatment, including annealing at a temperature of 480 °C, severe plastic deformation by highpressure torsion at room temperature and subsequent isothermal rolling at a temperature of 200 °C. The formation of a nanostructured state in the 1565ch alloy with a regulated distribution of the Al3Mg2, Al6Mn and Al3Zr phases both in the body and at the boundaries of aluminum grains made it possible to realize the effect of high-strain-rate superplasticity at a temperature of 300 °C at a rate of 10–2 s–1, the strain-rate sensitivity parameter was m = 0.7. Based on the results of mechanical tests, the creation of a metal-matrix composite reinforced with continuous boron fibers under conditions of superplastic pressing at a temperature of 350 °C was simulated in order to determine the technological parameters for the production of a metal-matrix composite. The simulation results show that the equivalent stresses in the fiber acquire a maximum value when compressed by 50%, but in this case the all-round compression pattern prevails, which does not lead to fiber destruction. Using the 1565ch alloy in a nanostructured state, the features of obtaining a multilayer metal-matrix composite using the “foil – fiber – foil” scheme by isothermal pressing in the low-temperature superplasticity mode were studied.