Joanna Sobota

Structure and Properties of CuCr0.6 Alloy after Severe Plastic Deformation

This paper focuses on the effect of rolling with cyclic movement of rolls (RCMR) on microstructure refinement, mechanical properties and electrical conductivity of CuCr0.6 alloy after applying different heat treatments (quenching and aging). It was found that the presence of second phase particles obtained during aging treatment has a significant effect on the formation of ultrafine grain (UFG) structure during the RCMR processing. The presence of high dislocation density inside subgrains and presence microshear bands are the marked features of the microstructure after aging at 500°C/2h and RCMR deformation. Whereas after aging at 700°C/24h and RCMR processing, fine precipitates were effective in inhibiting the grain/subgrain boundary motion. The RCMR processed alloy after aging at 500°C/2h shows high mechanical strength attributed to the high density of coherent precipitates and ultrafine grained structure. The RCMR processing induces a significant reduction of the electrical conductivity for samples at quenching state but for samples at aging state electrical conductivity was restored thanks to precipitation process.

Effect of Continuous RCS Deformation on Microstructure and Properties of Copper and Copper Alloys Strips

The aim of this work was to study the microstructure and mechanical properties of copper, brass CuZn36 and bronze CuSn6 strips annealed and after repetitive corrugation and straightening (RCS) process. The influence of process parameters on the functional properties of strips was investigated. The study found an increase in the yield strength and tensile strength of the material after RCS process. Crystallite size measurement confirmed the presence of nanoscale structures in the studied materials after deformation by RCS process. The used method of plastic deformation is promising for development materials with improved functional properties. The paper presents also the results of numerical simulations of Cu strip after corrugation on groove and tooth rolls and next straightening. Rolling process simulations were conducted using Forge 2011® based on the finite element method.