Investigations of the shear behaviour of aluminium alloys

• Applicant: Professor Dr.-Ing. Bernd-Arno Behrens
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2005 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 15868206

The shearing of bar material is the most efficient process for the production of forging raw parts. The pro-cess is used in the industrial large-scale production of steel forging raw parts. Aluminium raw parts are predominantly produced by less economic sawing processes, due to their material properties.During the first application period, the research was focused on identifying the general shearing behaviour of aluminium materials. Shear investigations of aluminium alloys were performed under defined process parameters and optimal parameters for the production of blanks from aluminium materials were deduced. At the end of the first period of eligibility, profound knowledge about achieving good shear qualities of different aluminium alloys under specific process parameters was available.In the project an experimental tool was developed to enable the shearing of aluminium bars under laboratory conditions with different forging presses and testing machines. The shear behavior of the material has previously been mapped by numerical simulation. With the developed tool, the shearing of four different aluminium alloys in two different generated microstructural conditions has been investigated. The variable process parameters were the shear clearance and the shear rate. When evaluating the investigation series the shear clearance turned out to be the essential process parameter. Good shear results have been achieved by shearing with small shear clearances. High shear rates only contributed to achieve good shear qualities in case of heat treatable aluminium alloys. During further investigations, axial stress was applied to the specimen during the shearing process, which did not improve the achieved quality.The aim of the second application period is to optimize the shearing process of aluminium materials and to adapt the shear quality to that of steel materials. For the implementation of further shear investigations the same tooling system is applied with modified process parameters. As the shear clearance was identified as the most important process parameter, a further investigation of it is planned. Results within the first application period indicate an improvement of the shear results by using scaled-down shear clearances. Furthermore, the relief grinding of the shear blades will be considered in detail. Further examinations will be implemented while varying the prevailing friction conditions of the shearing process.

• DFG Programme: Research Grants