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Copper matrix composites (Cu-MCs) have garnered significant attention due to their exceptional electrical, wear-resistant, and mechanical properties. Among them, Al2O3/Cu composites, reinforced with Al2O3, are a focal point in the field of high-strength, high-conductivity copper alloys, owing to their high strength, excellent electrical conductivity, and superior resistance to high-temperature softening. Cold deformation is an effective method for enhancing the mechanical properties of Al2O3/Cu composites. However, during cold deformation of large-cross-sectional Al2O3/Cu composites, the inhomogeneity in microstructure and properties induced by varying stress states cannot be overlooked. In this study, cold deformation of 1.12 wt% Al2O3/Cu large-cross-sectional composites was performed using a rolling process, coupled with finite element numerical simulations, to investigate the distribution characteristics of microstructure and properties during the rolling process. The results indicate that under cold deformation, the hardness of the material increases linearly from the surface layer to the core, while the change in electrical conductivity is minimal. The increase in hardness is closely related to variations in dislocation density and grain size, with dislocation density being the dominant strengthening mechanism. Quantitative analysis reveals that strain inhomogeneity during cold deformation is the primary cause of microstructural differences, leading to variations in mechanical properties at different positions. This study provides a theoretical basis for understanding the inhomogeneity of cold deformation in large-sized Al2O3/Cu composites and for controlling their microstructure–property relationships. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The pitting corrosion behaviors of high-strength metastable austenitic stainless steel (MASS) 14Cr10Mn with different cold rolling reductions (0 %, 10 % and 20 %) were investigated in simulated coastal atmospheric environments by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), electrochemical measurements and cyclic corrosion test. The cold rolling deformation noticeably increases the dislocation density in the steel. As the cold rolling reduction changes from 0 % to 20 %, the pitting potential and the polarization resistance decrease to some extent in 1 wt% NaCl solution. The cold rolling deformation increases the defect density and the contents of (Fe,Cr)-oxyhydroxides/hydroxides in the passive film on the specimen surface. After the wet-dry cyclic corrosion test, the corrosion pits initiate at the deformation band regions. The quantity, diameter and depth of the pits gradually increase with enlarging the cold rolling reduction.

Copyright of Iron Steel Vanadium Titanium is the property of Iron Steel Vanadium Titanium Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The extruded and solution-treated plates of 2195 Al-Li alloy were cold rolled by the reduction of 5%~25% followed by an artificially aging process, and then the effect of cold rolling deformation on its microstructure and mechanical properties were studied through microstructure analysis and tensile test. The results show that the 45° shear bands begin to appear among some fibrous structures in the thickness direction of the plate after the reduction reaches 20%. Furthermore, the bands can be distributed in the whole thickness of the plate when the reduction increases to 25%. After aging treatment(155℃ for 28h), the yield, tensile strength and final elongation of the cold-rolled plates firstly increase and then decrease with the reduction increase. When the reduction is 10%, the yield, tensile strength and final elongation of the plate reach their maximum values of 575MPa, 604MPa and 13.7%, respectively. After aging, the yield-tensile strength ratio of the sample increases from 90.8% to 97.4% with the reduction from 0 to 20%, and then slightly decreases to 97.1% with further increasing reduction to 25%. Therefore, for the extruded and solution-treated 2195 Al-Li alloy plate, the reduction of cold rolling should be controlled around 10%. [ABSTRACT FROM AUTHOR]

The influences of cold rolling deformation on the microstructures and corrosion behavior of laser metal deposition processed GH3536 alloy were investigated through electron backscattered diffraction and electrochemical tests. The results indicate that the deformed sample within a 15 % of reduction exhibits an excellent corrosion resistance in the simulated PEMFC solution, which can be mainly attributed to a small amount of deformation providing more nucleation sites for Cr to form compact Cr 2 O 3 passive films. In addition, an appropriate compressive residual stress reduces point defect concentrations in passive films and limits interfacial reaction kinetics. In comparison, the corrosion resistance of GH3536 alloy obviously decreases with an increase in deformation reduction from 15 % to 50 %. Apart from a strong increase in activation energy, high-density dislocations after a severe deformation will enhance the surface activity and result in the lattice distortion in the passive film, which deteriorates the corrosion resistance of cold-rolled GH3536 alloy samples. • The deformed sample within a 15 % of reduction exhibits an excellent corrosion resistance. • The corrosion resistance of GH3536 alloy obviously decreases after the severe deformation. • Difference in corrosion resistance is attributed to dislocation density and film compositions. [ABSTRACT FROM AUTHOR]

In the present study, Ti-10V-2Fe-3Al (Ti-1023) alloy was prepared by vacuum consumable melting and forging technique. The structural stability, microstructural evolution and mechanical behavior of the alloy were systematically investigated by X-ray diffraction, transmitting electron microscopy and mechanical testing. It is indicated that the structural stability, microstructure and mechanical behavior of Ti-1023 alloy are closely related to the cold deformation and heat treatment. Regardless of the solution treatments in single β phase region (833 ℃) or α + β phase region (753 ℃), double yielding occurs in the stress-strain curves of the alloy. This suggests that the β phases in the alloys with above solution treatments possess low structural stability, and stress induces β→α" martensitic transformation, leading to double yielding behavior. Severe cold rolling deformation and stress/strain induced martensitic transformation gives rise to the refinement of β grains and martensite variants. Since numerous dislocations and grain/phase boundaries induced by severe cold deformation can be used as nucleating sites for the precipitation of α phase, a large amount of fine α phase is precipitated out of the cold rolled Ti-1023 alloy after short aging at 550 ℃, therefore,the alloy exhibits a good balance between strength and ductility.

Copyright of Journal of Aeronautical Materials is the property of Editorial Board of Journal of Aeronautical Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The tendency of some copper-based binary alloys to oxidize has been studied by the thermogravimetry method. It has been established that, apart from their perfect cubic texture and the high strength properties, substrates made of the Cu-Ni, Cu-0.4% Cr, and Cu-1.6% Fe alloys also possess better anticorrosion properties at the temperature of the deposition of the epitaxial layers (700°C) than the substrates of pure copper. In the alloys containing disperse particles of a second phase, the oxidation resistance decreases in the inverse proportion to the particle size. The Cu-0.6% V ribbon, in which the vanadium particles reach a size of several microns, was even less resistant to oxidation than the copper substrate; therefore, it cannot be used for the deposition of functional layers at elevated temperatures. [ABSTRACT FROM AUTHOR]

The properties of Al-Cu-Mg alloys simultaneously depend on dissolving the maximum amount of Cu and Mg in the solution treatment and on achieving optimal ageing. The aim of this study is to analyze the effect on an Al-Cu4.5-Mg1.5-Si0.75 alloy, manufactured by continuous casting and hot rolling until achieving a reduction in its cross-section greater than 90%, of the dwell time at the solution temperature, 495 °C (4, 8, and 24 h), of the different ageing temperatures (160, 180, and 200 °C), and of cold rolling prior to ageing. The microstructural variations underwent the material during its manufacturing process, form its continuous casting to subsequent hot rolling, were analyzed by means of optical microscopy (OM) and scanning electronic microscopy (SEM), with characteristic energy dispersive X-ray (EDX) microanalysis. The crystalline phases present after the different solution and natural ageing treatments were identified and quantified by means of X-ray diffraction (XRD), concluding that Mg is easier to dissolve than Cu. The transient states associated with the Mg2Si phase are the most abundant. However, the longer the dwell time at the solution temperature, the greater the weight percentage of the transient states associated with the Al2Cu phase during ageing. The higher the ageing temperature, the faster the peak hardness is reached, but the lower its value. The ageing temperature that allows the highest hardness to be obtained was 160 °C. The maximum hardness value reached was 162 HV, obtained after a solution treatment at 495 °C for 4 h and ageing at 160 °C for 50 h. By means of prior cold rolling, the peak hardness values are reached more quickly and their values slightly exceed those obtained without this deformation. With ageing at 180 °C, 168 HV are reached after 6 h at this temperature.

Dependence of microstructure, texture evolution and mechanical properties of Al–Mg–Si–Cu alloy sheet on final cold rolling deformation was studied by means of tensile test, microstructure and texture characterization in this study. The results reveal that the different final cold rolling deformations have a great influence on the evolution of microstructure and texture, and final mechanical properties. Compared with the T4P treated (pre-aged at 80 °C for 12 h plus naturally aged for 14 days) alloy sheet A with a high final cold rolling deformation (75%), the T4P treated alloy sheet B with a lower final cold rolling deformation (50%) possesses almost identical strength and elongation, but a higher average r and a lower Δ r value. Compared with the annealed alloy sheet A, the density of finer particles in the annealed alloy sheet B is higher, which further can affect the evolution of microstructure and texture. After solution treatment, the two alloy sheets are comprised of equiaxed grains with somewhat different grain sizes, and the different textures, Goss {110}<001> and Cube {100}<001> orientations in the sheet A, while only Cube orientation with a low intensity in the sheet B. The relationship between texture and r value in the two alloy sheets was also analyzed by Visco-plastic self-consistent (VPSC) model. [ABSTRACT FROM AUTHOR]

As a metastable β titanium alloy developed for applications in aerospace industry, Ti-10V-2Fe-3Al alloy offers high strength, good fracture toughness and a limited cold workability. In the present study, the microstructure evolution and mechanical properties of Ti-10V-2Fe-3Al alloy undergoing cold rolling deformation were characterized by optical microscopy, X-ray diffraction, transmission electron microscopy and mechanical testing, in attempt to understand the relationship between the microstructural evolution and deformation behavior. It is revealed that the cold rolling deformation induces the formation of large amounts of α″ martensites in solution treated specimen. The stress/strain induced martensitic transformation leads to substantial refinement of β and α″ grains as well as preferential formation of α″ martensites. The microstructure evolution and the corresponding response of mechanical behavior were discussed, suggesting that the principal deformation mechanisms of Ti-10V-2Fe-3Al undergoing severe cold rolling involve stress/strain induced martensitic transformation and dislocation slip. [ABSTRACT FROM AUTHOR]

The properties of Al-Cu-Mg alloys simultaneously depend on dissolving the maximum amount of Cu and Mg in the solution treatment and on achieving optimal ageing. The aim of this study is to analyze the effect on an Al-Cu4.5-Mg1.5-Si0.75 alloy, manufactured by continuous casting and hot rolling until achieving a reduction in its cross-section greater than 90%, of the dwell time at the solution temperature, 495 °C (4, 8, and 24 h), of the different ageing temperatures (160, 180, and 200 °C), and of cold rolling prior to ageing. The microstructural variations underwent the material during its manufacturing process, form its continuous casting to subsequent hot rolling, were analyzed by means of optical microscopy (OM) and scanning electronic microscopy (SEM), with characteristic energy dispersive X-ray (EDX) microanalysis. The crystalline phases present after the different solution and natural ageing treatments were identified and quantified by means of X-ray diffraction (XRD), concluding that Mg is easier to dissolve than Cu. The transient states associated with the Mg2Si phase are the most abundant. However, the longer the dwell time at the solution temperature, the greater the weight percentage of the transient states associated with the Al2Cu phase during ageing. The higher the ageing temperature, the faster the peak hardness is reached, but the lower its value. The ageing temperature that allows the highest hardness to be obtained was 160 °C. The maximum hardness value reached was 162 HV, obtained after a solution treatment at 495 °C for 4 h and ageing at 160 °C for 50 h. By means of prior cold rolling, the peak hardness values are reached more quickly and their values slightly exceed those obtained without this deformation. With ageing at 180 °C, 168 HV are reached after 6 h at this temperature. [ABSTRACT FROM AUTHOR]