Optimize True Strain

The points ① - ⑦ show possible points in the deformation diagram. ⑦ is below the limit curve. The distance to the FLC is a measure of the deep drawing safety at this point.

If the values are above the flow limit curve, they can be optimized through various measures:

① to ② Superimpose additional compressive stresses in φ₂

③ after ④ Decrease natural strain

⑤ to ⑥ Increase in the degree of deformation through additional stretch-forming components in direction φ₂

Optimisation can be achieved by changing the blank dimensions, arrangement and shape of the drawing rods, dies or punch edge radius, lubrication, material or shape of the tool.19

⑧ to ⑨ The flow limit curve FLC can be increased by using thicker sheets or sheets with a higher hardening exponent ( n-value ). Likewise, tempering the tool or the circuit board can shift the FLC upwards.