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Experimental Study on Deep-Drawing Dies Made of Pre-Stressed UHPC
Katja Holzer1, Yuqi Zhang1, Lukas Martinitz1
1Chair of Metal Forming and Casting, Technical University of Munich, Walther-Meissner-Strasse 4, 85748 Garching, Germany.
Materials (Basel, Switzerland)
|January 25, 2025
Summary
Ultra-high-performance concrete (UHPC) shows promise for cost-effective deep drawing tools. Pre-stressing expansive UHPC with steel reinforcement improved tool performance, changing failure modes and increasing load capacity in trials.
Area of Science:
- Materials Science
- Manufacturing Engineering
Background:
- Deep drawing is a high-volume sheet metal forming process.
- Conventional steel tooling is expensive for prototypes and small series.
- Ultra-high-performance concrete (UHPC) offers a cost-effective alternative, but its strength limitations hinder complex applications.
Purpose of the Study:
- To investigate pre-stressing ultra-high-performance concrete (UHPC) using expansive agents and mechanical restraint.
- To evaluate the effectiveness of this method in enhancing UHPC's suitability for deep drawing applications.
Main Methods:
- UHPC was modified with an aluminum powder-based expansive agent to induce free volume increase.
- Push-out tests were conducted on specimens with steel reinforcement to restrain expansion and measure strength increase.
- Deep drawing experiments were performed using dies made from expansive UHPC under restrained conditions.
Main Results:
- No significant pre-straining effect was measured in push-out tests after 3 and 12 months.
- Deep drawing dies made from restrained expansive UHPC withstood a maximum load of 110 kN.
- The failure mode shifted from complete fracture (UHPC only) to surface degradation of the drawing radius after 15 strokes.
Conclusions:
- Restrained expansive UHPC shows potential for deep drawing applications despite limited measurable pre-strain.
- The modified UHPC dies exhibit improved durability and load-bearing capacity compared to standard UHPC.
- This approach offers a viable, cost-effective solution for tooling in sheet metal forming.
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