How much of a gap to put aluminum sheet stretch?
Into a small cross-sectional area of the tubular member from a large cross-sectional area of the billet, called the stretch factor. That is, each of the cross-sectional area than the cross-sectional area of the stretched before stretching namely: m = A0 / An-1. For cylindrical parts, m1 = d1 / D0, the first stretch of the coefficients can be about 0.5, that is the diameter of the first half after stretching is stretching before the blank diameter.
Subsequent times stretching factor is generally about 0.7 to 0.8. Stretching the blank calculation, roughly stretching before and after the blank according to the principle of equal area is calculated blank dimensions.
Tensile aluminum plate gap value = 1.3 ~ 1.4t (first draw), 1.15 ~ 1.2t (secondary drawing), 1.1t (last stretch). Tensile properties of aluminum sheet is not as low-carbon steel, is very easy to pull broken when stretched. Stretching depends on the height of 45mm diameter is much tensile member.
