Microstructures and textures of a Cu–Ni–Si alloy processed by high-pressure torsion

Microstructure and texture evolution in a Cu–Ni–Si alloy processed by equal-channel angular pressing

“…In the present EBSD analysis, the misorientation angles were measured as pixel-to-pixel instead of grain-to-grain and this introduces larger numbers of low-angle boundaries [36,37] so that the misorientation distributions after 8 and 12 passes are significantly lower than the theoretical curves for random distributions as depicted by the solid lines [38,39]. It is interesting to note that the variation of the fraction of misorientation angles for the sample after 12 ECAP passes is essentially identical to the variation reported at the edge of the disk of the same alloy after processing by HPT for 0.5 turn at room temperature under an imposed pressure of 6.0 GPa [26]. Using a channel angle of 135° in the ECAP die, a total of 12 passes gives a strain of ~6.…”

“…An earlier study presented the initial microstructure, grain boundary misorientation histogram and orientation distribution function (ODF) section at φ 2 = 45° for the material before ECAP processing [26]. In this earlier report, the initial grain size was ~20 µm and the EBSD analysis recorded a high fraction of about 95% of high-angle grain boundaries (HAGB) and a majority of the grain boundaries of ~35% were first-order twins (Σ3 60° <111>).…”

“…These alloys are important because it is known that a dilute amount of elements having very low solubilities permits precipitation strengthening which preserves the high strength of the alloy and retains its electrical conductivity. To date, there are reports of the hardness, electrical conductivity and some microstructural features in a Cu-2.9Ni-0.6Si (wt.%) alloy after HPT for 5 turns [24], the evolution of hardness and microstructure in a Cu-2.5Ni-0.6Si (wt.%) alloy after ECAP up to 12 passes and after HPT up to 10 turns [25] and the evolution of microstructure and texture in a Cu-2.5Ni-0.6Si (wt.%) alloy processed by HPT up to maximum of 10 turns [26]. Accordingly, the present research was initiated to obtain a detailed understanding of the evolution of microstructure and texture in a Cu-2.5Ni-0.6Si alloy during processing by ECAP.…”

Significance of grain refinement on microstructure and mechanical properties of an Al-3% Mg alloy processed by high-pressure torsion

“…The lower elongations in the disk for the 10 HPT turns are due to the occurrence of faster grain growth at the high testing temperature where the faster grain growth is attributed to the presence of higher fractions of high-angle grain boundaries with increasing numbers of HPT turns [37][38][39] whereas no significant change in grain size was observed in the Al-Mg alloys after 5 turns as shown in Figs 2 and 3 and Table 1.…”

Effects of Zr and (Ni, Si) additions on properties and microstructure of Cu–Cr alloy

“…Copper alloy with Ni and Si additions exhibits high strength and medium conductivity for lead frame materials due to precipitation of nanosized Ni x Si [23,24]. Multi-phase strengthening is expected to apply to copper alloys with high strength and high conductivity in the present work.…”