STRUCTURE REFINEMENT PECULARITIES AND SOLID SOLUTION FORMATION IN THE CAST Cu-Fe ALLOY, SUBJECTED TO SEVERE PLASTIC DEFORMATION

• Main Authors: A.V. Lukyanov, A.A. Churakova, A.V. Ganeev, V.D. Sitdikov, D.V. Gunderov
• Format: Article
• Language: Russian
• Published: Tver State University 2014-11-01
• Series: Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов
• Subjects: nanocomposite; high pressure torsion deformation; CuFe− alloy.; Cu-Fe alloy
• Online Access: http://physchemaspects.ru/archives/2014/%D0%A4%D0%A5-2014.%20%D0%9B%D1%83%D0%BA%D1%8C%D1%8F%D0%BD%D0%BE%D0%B2%20%D0%90%D0%92.pdf
• ISSN: 2226-4442; 2658-4360

The effect of high pressure torsion (HPT) on the microstructure of Cu−Fe 36% wt alloy has been studied. The initial Cu− Fe alloy has a dendritic structure, the length of dendrites is up to 100 μm. As a result of HPT (20 anvil rotations at 400°C) the nanostructured state is formed. The average grain size of the Cu− and α−Fe is 60 and 35 nm correspondingly. The refinement of α−Fe dendrites occurs, and a microstructure with Fe inclusions with a size from 0,1 to 5 μm distributed in the copper matrix forms. A volume fraction of the Fe phase reduces from initial 37% up to 15% after HPT. The concentration of copper in the lattice dissolved iron reaches 20%. Subsequent annealing at 700°C for 1 hour results in some coarsening of α−Fe particles, as compared to the state after HPT. However, the dendritic structure typical of the cast alloy does not recover; it remains dispersed with a size of α−Fe particles less than 20 μm. As a result of HPT the alloy microhardness increased from 1800 to 4000 MPa. The subsequent annealing at T=700°C decreased the microhardness to 2700 MPa, but this value is 1,5 times higher than that in the initial as-cast state.