FOMM: Forming of new metallic materials

• Unité de recherche: PCRD EU
• Numéro de projet: 96.0219-2
• Titre du projet anglais: FOMM: Forming of new metallic materials

Mots-clé (Anglais)

Automotive industry; weight reduction; new Al alloys; high-strength steels; forming simulation; material data

Autre Numéro de projet (Anglais)

EU project number: BRPR-CT96-0226

Programme de recherche (Anglais)

EU-programme: 4. Frame Research Programme - 2.1 Industrial and materials technologies

Description succincte (Anglais)

See abstract

Partenaires et organisations internationales (Anglais)

Renault, Fiat, Volvo, Daimler-Chrysler, Sollac, ESI, Autoform, IFU Stuttgart

Résumé des résultats (Abstract) (Anglais)

For todays car industry, environmental concerns turn more and more into an economical and technological challenge when developping new cars. Consequent use of lightweight materials is an important factor to achieve a reduction of fuel consumption. Material suppliers are continuously developping new improved products like bare high-strength steels and aluminium alloys or advanced materials like laminated or pre-painted qualities. Car producers and material suppliers are intensively working to demonstrate the suitability of these new materials for industrial production processes. An important tool is forming simulation by means of specialized software codes. For a good understanding and reliable forming simulation results, the availability of relevant material data sets is essential.

Alusuisse (now Alcan) has provided 7 different aluminium qualities to all project partners. Tensile tests have been performed on these materials as well as on the 11 steel qualities analyzed in this project. Experimental work for determination of forming limit curves has been performed and coordinated with all partners. Energy absorption capacity of the aluminium alloys has been analyzed in compression tests. Experimental results of other partners have been collected and consolidated.

Experimental results from uniaxial and equibiaxial tensile tests have been compared to the forming behaviour predicted by different strain-hardening laws. It has been shown for all materials that new strain-hardening laws are more accurate for the description of the forming behaviour. Best predictions can be obtained by the introduction of the instantaneous value of the strain-hardening coefficient n instead of assuming a constant value.
All partners experimental data for all 18 materials have been compiled on a CD-ROM
Stress-strain curves determined by various methods (tensile, bulge and plane strain tests) showed some differences especially for the steel variants. This is due to the higher anisotropy of these materials.

Comparisons of forming limit curves determined by the different partners showed some significant discrepancies. This could be mainly explained by differences in test methodologies. Different methods to extract one unique forming limit curve from all experimental data have been investigated and discussed. Theoretical description of forming limit curves seems to be possible.

The capacity of energy absorption of the aluminium alloys Ac-121 (AA 6016), Ecodal (AA 6181A) and AA 5182 has been analyzed in quasi-static collapse tests. These tests have been performed on circular cylindrical tubes in several tempers: as-supplied and after different heat treatments which should simulate various paint bake cycles. It has been shown that new materials like Ecodal with an increased strength level perform better in energy absorption than conventional materials.

Références bases de données (Anglais)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 96.0219-2