Influence of AI-Cu-Mn-Fe-Ti Alloy Composition and Production Parameters of Extruded Semi-Finished Products on their Structure and Mechanical Properties

摘要

Studies have been conducted as to the effect of Cu, Mn, Fe concentration changes in Al-Cu-Mn-Fe-Ti alloy, the conditions of thermal and deformational treatment of ingots and extruded rods 40 mm in diameter on the microstructure, phase composition and mechanical properties. It has been determined that changing Al-6.3Cu-0.3Mn-0.17Fe-0.15Ti alloy to Al-6.5Cu-0.7Mn-0.llFe-0.15Ti causes an increase in the strength characteristics of extruded rods at the room temperature both after molding and in tempered and aged conditions, irrespective of the conditions of thermal treatment of the initial ingot (low-temperature annealing 420 °C for 2 h, or high-temperature annealing at 530 °C for 12 h). Increasing the extruding temperature from 330 to 480 °C, along with increasing Cu, Mn and decreasing Fe in the alloy Al-Cu-Mn-Ti, is accompanied by the increased level of ultimate strength in a quenched condition by 25% to 410 MPa, irrespective of the annealing conditions of the original ingot. An opportunity to apply the Al-6.3Cu-0.3Mn-0.17Fe-0.15Ti alloy with low-temperature annealing at 420 °C for 2 h and the molding temperature of 330 °C has been found to produce rods where, in the condition of full thermal treatment (tempering at 535 °C + aging at 200 °C for 8 hours), a structure is formed that ensures satisfactory characteristics of high temperature strength by resisting to fracture for more than 100 hours at 300 °C and 70 MPa. EDS, tensile properties, quenching, hot deformation, aging, heat treatment, Al-Cu-Mn-Fe-Ti.