How can the wire producer or the customer control the effectivnes of annealing process to get enough soft wire? Are there some limit values of mechanical properties to test Al-conductor class2 after annealing?
The production of an Al conductor of a certain diameter is achieved by drawing through nozzles. In the process of drawing, the material increases its mechanical strength and stiffness depending on the degree of deformation. The drawn wire Al wire is rolled into reels with a mass of 500 to 1000kg. In order to reduce the mechanical hardness, complete thermal treatment is carried out.
To achieve strength, the last drawing passes through calibration nozzles with a controlled deformation rate (withdrawal rate) are carried out.
We need flexible wire for easy installation and thats swhy pecify soft annealed properties of the conductor. We did a bad experience win the past ith too stiff and brittle behaviour udring the instalation dnd try to find some concrete values (borders) to specify the accurate properties to the wire supplier. I tend to limit maximum tensile strength of the Al-wire to 30 MPa. Is it realistic?
The yield strength of pure aluminum is 7-11 MPa, and in some aluminum alloys it reaches 200 to 600 MPa. This means that you tend to target pure Al (99.95%) and be heat treated after the last pull of the wire.