Hybrid ultrafine grained materials produced by high pressure torsion extrusion

• Applicants: Professor Dr.-Ing. Horst Hahn; Dr. Julia Ivanisenko
• Subject Area: Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 353142053

• Final Report Year: 2020

Final Report Abstract

During the fulfilment of the project, a scientific approach for the synthesis of new hybrid ultrafine-grained materials with high strength and ductility on the base of a novel severe plastic deformation (SPD) processing technique, referred to as High Pressure Torsion Extrusion (HPTE) was developed. Hybrid materials, investigated in the present project, are metal-based composites comprised of two or more constituents. Their properties are crucially determined by the inner architecture, achieved by HPTE processing along with concurrent nanostructuring. This specific architecture may include processing of gradient structure i.e modified microstructure (and sometimes, phase composition) in particular areas of the sample, and/or introduction of structural elements (reinforcements) with specially designed shape. As model materials pure copper and aluminum, also reinforced with iron wires were used to demonstrate various kinds of inner specimen architectures. The experimental work on the processing, structure and mechanical properties had been complemented by numerical simulations. The major part of the originally planned tasks has been fulfilled. In particular: 1. The peculiarities of the material flow at HPTE were analyzed using finite element method. 2. A constitutive description of tensile deformation of gradient materials obtained using HPTE was proposed. 3. Gradient microstructure development at various HPTE regimes was studied in Cu with two different grades of purity, Al and Al 6101 alloy. Tensile properties of as-obtained samples were evaluated. It was established that tensile behavior of all studied materials after HPTE with gradient structure is similar to that of these materials after SPD techniques providing a homogeneous structure. In particular, significant increase of yield and ultimate strength (3-5 times as compared with coarse grained counterparts) was achieved, however the uniform elongation had not been improved despite the presence of gradient microstructure. 4. Hybrid specimens including Cu matrix and Al-wires, Cu matrix and Fe-wires, were manufactured, processed by HPTE, characterized, and their mechanical properties were evaluated. The investigations conducted show that the HPTE-processing of hybrid samples with embedded straight wires leads to the creation of helical architecture of these wires and significant change of the wire cross section shape. Combinations of Cu-matrix with helical architecture of Al wires (hard matrix/soft wires) had not influenced the tensile behavior of hybrid samples, whereas Cu-Fe hybrid samples demonstrated improved mechanical properties.

Publications

• Modelling of High Pressure Torsion using FEM, Procedia Engineering, 2017, 207, 1445-1450
  Kulagin R., Beygelzimer Y., Ivanisenko Y., Mazilkin A., Hahn H.
  
• Novel SPD method of High Pressure Torsion Extrusion and its applications. Proceedings of the International workshop on Giant Straining Process for advanced Materials (GSAM 2017) ed. by K. Edalati, Y. Ikoma and Z. Horita. Kyushu University, 2017
  Yu. Ivanisenko, R. Kulagin, A. Mazilkin, A.A. Sirotin, M.M. Murashkin
  
• nstabilities of interfaces between dissimilar metals induced by high pressure torsion, Materials Letters, 2018, 222, 172-175
  Kulagin R., Beygelzimer Y., Ivanisenko Y., Mazilkin A., Straumal B., Hahn H.
  
• Evolution of microstructure and hardness in aluminum processed by High Pressure Torsion Extrusion (2019) Materials Science and Engineering A, 762, art. no. 138074
  Omranpour, B., Ivanisenko, Y., Kulagin, R., Kommel, L., Garcia Sanchez, E., Nugmanov, D., Scherer, T., Heczel, A., Gubicza, J.
  
• High-pressure torsion driven mechanical alloying of CoCrFeMnNi high entropy alloy, Scripta Materialia, 2019, 158, 29-33
  Kilmametov A., Kulagin R., Mazilkin A., Seils S., Boll T., Heilmaier M., Hahn H.
  
• Mathematical Model of Deformation under High Pressure Torsion Extrusion. Metals 2019, 9, 306
  Kulagin, R.; Beygelzimer, Y.; Estrin, Y.; Ivanisenko, Y.; Baretzky, B.; Hahn, H. A
  
• Structure and tensile strength of pure Cu after high pressure torsion extrusion (2019) Metals, 9 (10), art. no. 1081
  Nugmanov, D., Mazilkin, A., Hahn, H., Ivanisenko, Y.