Reinforcement systems for dies with non-circular-symmetrical cross-sections

Funding period:

Start: 1. October 2018
Ende: 30. September 2020
Verlängerung: 30. September 2021

Abstract

Cold-forging tools are key components in forming processes due to their influence on geometrical accuracy and profitability. Apart from wear, fatigue failure caused by cyclic loads is the main reason for tool failure. To avoid crack initiation by fatigue, occurring tensile stresses have to be reduced. Furthermore, a stiff tool layout is required to achieve high accuracy of the produced parts. A possible way to both minimize the tensile stresses and increase the stiffness of the tools is the use of reinforcements. Reinforcements induce radial compressive prestresses, thus shifting the overall stress state from a tensile to a less critical compressive stress state. This is achieved by pressing the die into a reinforcement ring made of ductile steel. More complex parts with higher aspect ratios as well as non-uniformly distributed functional elements lead to new challenges for forming tools. By using a non-circular-symmetrical cross-section or a non-circular-symmetrical load the prestress cannot be applied uniformly with conventional reinforcement systems. This leads to sinking tool life quantities and thus has a negative influence on profitability. The main goal of the project is the development and investigation of suitable reinforcement systems for dies with non-circular-symmetrical cross-sections in order to improve the tool performance.

Research groups

• Bulk Metal Forming

Publications