Properties Of Alloys Research Articles

A study on the hydrolytic properties of CaxSiy alloys

A study on the hydrolytic properties of CaxSiy alloys

Effect of Zn on Microstructure and Wear Resistance of Sn-Based Babbitt Alloy

Tin-based Babbitt alloys are a widely used bearing bushing material which have good comprehensive properties. However, problems such as high-temperature softening and insufficient bearing capacity occur during their use, so the optimization of tin-based Babbitt alloys has become a research hotspot. In this paper, ZChSnSb11-6 alloy was mainly prepared by the gravity casting method, and different amounts of Zn were added to the alloy (the mass fraction values were 0 wt.%, 0.05 wt.%, 0.1 wt.%, 0.15 wt.%, and 0.2 wt.%, respectively). Through the hardness test, the tensile test, the friction and wear test, and the microstructure observation of the prepared alloy, the influence of Zn on the organization and properties of the ZChSnSb11-6 alloy was analyzed. The results show that the size of the SnSb hard phase changed with the increasing content of Zn. The size of the hard phase of the SnSb tended to increase first and then decrease, and the number of phase particles increased first and then decreased, resulting in changes in performance. Through comparison, it was learned that the addition of Zn can effectively improve the hardness, tensile strength, yield strength, and wear resistance of the alloy, but the elongation rate was reduced. When the Zn content was 0.1 wt.%, the hardness value of the alloy reached the maximum value, 25.82 HB, which increased by 7.3% when compared with the sample without Zn. The hardness of the Zn, 0.15 wt.%, is close to that of the Zn, 0.1 wt.%. Compared to the sample without Zn, the tensile strength and elongation of the alloy were maximized at a Zn content of 0.15 wt.%. Compared to the sample without the Zn, the tensile strength was increased by 21.29%, and the elongation rate was increased by 46%. An analysis showed that the alloy has good comprehensive mechanical properties when the Zn content is 0.15 wt.%.

Effect of Loading Direction on Tensile-Compressive Mechanical Behaviors of Mg-5Zn-2Gd-0.2Zr Alloy with Heterogeneous Grains

The tension-compression yield asymmetry caused by the strengthening of Mg-Zn-Gd-Zr alloy due to extrusion deformation is an important issue that must be addressed in its application. In this study, the effects of loading direction on the tensile and compressive mechanical behaviors of Mg-5Zn-2Gd-0.2Zr alloy were systematically investigated. As the loading angle (the angle between the loading direction and the extrusion direction) increases from 0° to 30°, 45°, 60° and 90°, the tensile yield strength decreases more significantly than the compressive yield strength. Consequently, the tension-compression yield asymmetry is gradually improved. Additionally, the ultimate compressive strength decreases more markedly than the ultimate tensile strength with the increment of the loading angle. In tensile tests conducted at 0°, 30° and 45°, two distinct stages of decreasing strain hardening rates are typically observed. For the 60° and 90° tensile tests, one unusual ascending stage of strain hardening rate is observed. For all compressive tests, three stages of strain hardening are consistently noted; however, the increment in strain hardening rate caused by {10–12} extension twinning decreases with the increasing loading angle. A model combining loading angle and Schmid factor distribution was established. The calculated results indicate that the dominant deformation modes during the yielding process also vary significantly with the loading conditions. This clarification highlights the differences in yield strength variations between tension and compression. Finally, an analysis of the plane trace and crack propagation direction near the fracture surface reveals the fracture mechanisms associated with tensile and compressive tests at different loading directions. This study promotes understanding of the mechanical behaviors of Mg-5Zn-2Gd-0.2Zr alloy under different loading directions, and helps to thoroughly elucidate the anisotropic effects of texture on the mechanical properties of magnesium alloys.

Improving strength-conductivity synergy of Al-Cu-(Sn/Er) alloy with nanoscale substructure

As a conductive material for power transmission, Al-Cu alloy is widely used in power engineering, microelectronics and other fields. In view of the contradiction between the conductivity and strength of aluminum alloy, Sn and Er elements were selected to micro-alloy Al-Cu alloy. Al-Cu, Al-Cu-Sn and Al-Cu-Sn-Er alloys were prepared by near-liquidus casting. After solution treatment, it was subjected to three-stage alternating process of rolling and aging. The effects of micro-alloying and alternating process on the microstructure and properties of Al-Cu alloy were studied. The results show that the precipitated phase Al2Cu of Al-1.12 Cu alloy is rod-shaped after the first-stage process, and the average size is about 278±87 nm. The precipitated phases in the Al-Cu-Sn alloy are Al2Cu (average size of about 206±79 nm) and nano-sized β-Sn particles. The fine β-Sn nanoparticles in the Al-Cu-Sn-Er alloy heterogeneously nucleated on Al8Cu4Er (average size of about 167±45 nm), making Al8Cu4Er grow into particles. After secondary processing, stacking faults (SFs) appeared in the substructures of the three alloys, and the precipitated phases were further refined. The size of most precipitated phases in Al-1.13Cu-0.12Sn and Al-1.01Cu-0.15Sn-0.22Er alloys is reduced to nanometer level. After the three-stage process, some of the Al2Cu precipitates in the Al-Cu alloy are also refined to the nanometer level, and the precipitates in the other two alloys are all refined to the nanometer level. Nanotwins also appear in Al-1.01Cu-0.15Sn-0.22Er alloy. The tensile strength of Al-1.13Cu-0.12Sn and Al-1.01Cu-0.15Sn-0.22Er alloys after three-stage alternating process is 303 MPa and 327 MPa, respectively. The elongations are 21.6 % and 23.3 %, respectively. The relative conductivity was 61.7 %IACS and 59.8 %IACS, respectively. The synergistic effect of microalloying of Sn and Er elements and three-stage alternating processing technology not only reduces the size of precipitates and twins in the alloy to the nanometer level, but also adjusts the distribution of dislocation tangles and stacking faults (SFs), improves the substructure configuration, and improves the mechanical and electrical properties of conductive aluminum alloys.

Achieving strength-ductility balance in AZ31-WE43 Mg alloys by symmetric extrusion-shear process at various temperatures

The development of composites that simultaneously improve strength and plasticity is a challenging task, especially in Mg alloys. The focus of this study is to create a novel multiscale gradient structure (GS) in Mg laminates to exhibit optimal strength-plasticity synergies through a temperature-controlled extrusion shear (TCES) and extrusion composite process with preset grain sizes. Initially, the gradient structure is formed by a short extrusion process, leading to an increase in the average grain size of the elongated coarse grains from the middle layer of the equiaxed fine grain zone to the elongated coarse grain surface layer. The resulting gradient structure improves the material synergy. The microstructure evolution mechanism of the alloy during symmetric plastic deformation was analyzed. The initial grains underwent DDRX, CDRX, and shear deformation-induced dynamic recrystallization (SDDRX) during the RZ extrusion stage, the grains were significantly refined, and the basal texture intensity was significantly weakened during the SD extrusion stage. The effect of extrusion temperature (400 °C, 450 °C, 500 °C) on the alloys in the forming zone after ES extrusion was further investigated. Tensile tests on Mg laminates prepared by the extrusion method showed that the ultimate tensile strength (UTS) of the samples prepared at 450 °C was 265 MPa and the elongation (EL) was 23.8 %. The significant improvement in the yield tensile strength (YTS) of the composite Mg alloys post-ES processing is primarily attributed to the fine-grained (FG) interior, while the increase in elongation is due to the coarse-grained (CG) exterior. This study presents a novel approach to enhancing the mechanical properties of Mg alloys, offering a promising direction for the development of advanced materials with superior strength and ductility.

Al-Ti-C (CNTs) master alloys improve room temperature and high-temperature mechanical properties of ZL205A alloy

The insufficient high-temperature properties of Al-Cu alloys represent a significant obstacle to their further development. The use of master alloy refiners can enhance the mechanical properties while refining the grains. This paper describes the preparation and characterization of Al-Ti-C (CNTs) master alloys containing submicron TiC particles through the aluminum melt reaction method, utilizing graphite powders (GPs) and (CNTs) as carbon sources,respectively.The effects of these two types of intermediate alloys on the microstructures and high-temperature mechanical properties of the ZL205A alloy were investigated at varying additive amounts. The results indicate that the Al-Ti-C (CNTs) master alloys contain TiC particles measuring up to 183 nm and 480 nm, respectively, with the Al-Ti-CNTs demonstrating a superior effect on the refinement of the ZL205A alloy. The optimal mechanical properties were achieved upon the addition of 0.3 wt% of the master alloy to the ZL205A alloy. The mechanical properties improved from 341.53 MPa (yield strength), 371.68 MPa (tensile strength), and 3.3 % elongation without the addition of master alloys to 413.20 MPa, 471.82 MPa, and 11.2 % with the addition of Al-Ti-CNTs and to 440.85 MPa, 492.61 MPa, and 10.8 % with the addition of Al-Ti-C, respectively.At a high temperature of 300°C, the mechanical properties of the ZL205A alloy improved from 144.0 MPa and 10.8 % (Al-Ti-C) to 174.87 MPa and 11.2 %, and 195.1 MPa and 13.8 % (Al-Ti-CNTs). The TiC particles generated in situ under a different carbon sources demonstrated distinct mechanisms in the grain refinement of the ZL205A alloy. TiC (GPa) with a larger size primarily impeded the further growth of grains, while TiC (CNTs) promoted the formation of crystalline nuclei and heterogeneous nucleation sites, thereby achieving grain refinement. Large-sized TiC particles prepared using graphite as the carbon source hindered further grain growth, whereas TiC produced using carbon nanotubes promoted the formation of nuclei and heterogeneous nucleation sites, resulting in grain refinement. In addition, both types of TiC particles contribute to the densification and strengthening of the ZL205A alloy through fine grain strengthening, precipitation strengthening, Orowan strengthening, load transfer strengthening, the pinning effect, and thermal mismatch strengthening. However,TiC(CNTs) exhibits a greater contribution to strength due to its high quantity and small size.

Influence of Copper-Iron (CuFe) and Copper-Tin (CuSN) alloys over mechanical strength properties in crimping process

This study investigates the comparative performance of Copper-Iron (CuFe) and Copper-Tin (CuSn) alloys in crimping processes, with a focus on their mechanical, electrical, and corrosion-resistance properties. Crimping is a critical method for creating reliable electrical and mechanical connections, particularly in environments subjected to significant mechanical stress and varying temperatures [1]. CuFe alloys, known for their superior mechanical strength and hardness, present challenges in crimping due to their increased resistivity and reduced ductility. Conversely, CuSn alloys offer a balance between electrical conductivity, ease of crimping, and corrosion resistance, making them a preferred choice in many industrial applications. This research aims to provide a comprehensive analysis of how the distinct properties of CuFe and CuSn alloys influence the crimping process, ultimately guiding material selection for optimized performance in various applications [2]. Experimental data will be drawn from tensile strength tests, electrical resistance measurements, and corrosion tests, providing a holistic understanding of the advantages and limitations of each alloy.

Influence of twinning thickness on the mechanical properties of crystalline-amorphous dual-phase CoCrFeNiMn high entropy alloy

This study employs molecular dynamics simulation to investigate the influence of twin thickness on the mechanical properties and plastic deformation mechanisms for crystalline/amorphous dual-phase CoCrFeNiMn high-entropy alloy with varying amorphous layer thicknesses. The results revealed that for a minor amorphous layer thickness (d) of 1 nm, increasing the twin thickness (h) decreased average flow stress and peak stress within the models. It can be attributed to the fact that at smaller h, twin boundaries effectively hinder dislocation motion. However, as h increases, dislocation storage near twin boundaries and subsequent large-scale FCC→HCP phase transformation become more robust, reducing stress. On the other hand, when d thickness increases to 7 nm, stable average flow stress is observed due to thicker shear band formation during plastic deformation. Regardless of whether d was 1 nm or 7 nm, an increase in twin thickness augmented the likelihood of FCC→HCP phase transformation.

Effect of metalloid element on the microstructural and mechanical properties of AlCoCrCuFeNi high-entropy alloys

ABSTRACT The impact of the metalloid element silicon (Si) addition on the microstructural and mechanical properties of the AlCoCuCrFeNiSix high-entropy alloy system is examined in this paper. The alloys were synthesized using a vacuum arc melting route. X-ray diffraction was used to analyse the current high-entropy alloys’ phase formation to comprehend the alloying process’s behaviour. It is evident from the peak pattern of the X-ray diffraction that the inclusion of Si promotes the growth of body-centred cubic structures. The microhardness and wear resistance were increased by increasing the Si content from 0 to 0.9. Si presence enhances the hardness of the alloys and strengthens the grain boundary. Improved hardness and wear resistance results from the enhanced body-centred cubic-phase formation, which poses a barrier to the dislocation movement and prevents further deformation. Furthermore, the inclusion of Si improved corrosion resistance in potentiodynamic polarization measurements. Excellent compressive strength is possessed by all of the high-entropy alloys with Si addition.

Effects of Thermal Variables of Solidification on the Microstructure and Hardness of the Manganese Bronze Alloy Cu-24Zn-6Al-4Mn-3Fe

The Cu-24Zn-6Al-4Mn-3Fe alloy is mainly used for the manufacture of sliding bushings in the agricultural sector due to its high mechanical properties in the cast state. Understanding how the casting thermal parameters affect the microstructure and impact the properties of alloys is fundamental to optimizing manufacturing processes and improving performance during their application. In this study, the Cu-24Zn-6Al-4Mn-3Fe alloy was unidirectionally solidified under non-steady heat flow conditions using a water-cooled graphite base for heat exchange. Seven points were monitored along the longitudinal region of this ingot, and the data to obtain the solidification variables were extracted using an acquisition system. The cooling rates varied from 4.50 °C/s to 0.22 °C/s from the closest to the furthest position from the heat extraction point. The microstructure was analyzed via optical microscopy, scanning electron microscopy and X-ray diffraction in order to characterize the phases and intermetallic elements present in the material. The mechanical properties were evaluated through hardness and microhardness tests throughout longitudinal extension of the solidified part. The results showed an increase in hardness and microhardness with a decrease in the cooling rate, which may be related to the increase in size and the κ phase fraction with a decrease in the cooling rate, as analyzed via optical microscopy and scanning electron microscopy. Furthermore, in all positions, there was no significant change in the amount of the α phase retained, with the matrix being mainly composed of the β phase and a small content of approximately 2% of the α phase.

Microstructure and Mechanical Properties of Thick-Walled WE43A Alloy Fabricated by Wire Arc Additive Manufacturing

Microstructure and Mechanical Properties of Thick-Walled WE43A Alloy Fabricated by Wire Arc Additive Manufacturing

Microstructural Evolution and Mechanical Properties of Extruded AZ80 Magnesium Alloy during Room Temperature Multidirectional Forging Based on Twin Deformation Mode.

This study investigates the preparation of ultrahigh-strength AZ80 magnesium alloy bulks using room temperature multidirectional forging (MDF) at different strain rates. The focus is on elucidating the effects of multidirectional loading and strain rates on grain refinement and the subsequent impact on the mechanical properties of the AZ80 alloy. Unlike hot deformation, the alloy subjected to room temperature MDF exhibits a lamellar twinned structure with multi-scale interactions. The key to achieving effective room temperature MDF of the alloy lies in combining multidirectional loading with small forging strains per pass (6%). This approach not only maximizes the activation of twinning to accommodate deformation but ensures sufficient grain refinement. Microstructural analysis reveals that the evolution of the grain structure in the alloy during deformation results from the competition between {101¯2} twinning or twinning variant interactions and detwinning. Increasing the forging rate effectively activates more twin variants, and additional deformation passes significantly enhance twin interaction levels and dislocation density. Furthermore, at a higher strain rate, more pronounced dislocation accumulation facilitates the transformation of twin structures into high-angle grain boundaries, promoting texture dispersion and suppressing detwinning. The primary strengthening mechanisms in room temperature MDF samples are grain refinement and dislocation strengthening. While increased dislocation density raises yield strength, it reduces post-yield work hardening capacity. After two passes of MDF at a higher strain rate, the alloy achieves an optimal balance of strength and ductility, with a tensile strength of 462 MPa and an elongation of 5.1%, significantly outperforming hot-deformed magnesium alloys.

The role of C content on the glass-forming ability and magnetic properties of FeSiBPC amorphous alloys

The role of C content on the glass-forming ability and magnetic properties of FeSiBPC amorphous alloys

An in vitro and in vivo study of biodegradable Zn–Cu–Li alloy with high strength and ductility fabricated by hot extrusion combined with room-temperature ECAP

Deformation processing is a commonly used strategy to improve the microstructure and hence mechanical properties of biodegradable Zn alloys. However, a single conventional processing method is usually limited in achieving this goal. In this work, hot extrusion combined with room-temperature equal channel angular pressing (ECAP) was used to fabricate biodegradable Zn–Cu–Li alloy. Compared to the hot-extruded alloy, the further ECAPed alloys have significantly finer Zn grains and precipitate more submicron- and nano-sized ε-CuZn4 particles. Moreover, the 4-pass as-ECAPed alloy exhibits the best comprehensive mechanical properties with yield strength of 315 ± 3 MPa, ultimate tensile strength of 444 ± 13 MPa and elongation of 81 ± 5%, which are 13.3%, 38.8% and 72.3% higher than those of the hot-extruded alloy, respectively. In addition, in vitro and in vivo tests were performed on the 4-pass as-ECAPed alloy to evaluate its corrosion behavior, antibacterial property, cytotoxicity and biocompatibility. In vitro results showed that the 4-pass as-ECAPed alloy exhibits better corrosion resistance than the 8-pass alloy. Also, it shows good antibacterial property, hemocompatibility and cytocompatibility. In vivo results demonstrated that the 4-pass as-ECAPed alloy exhibits faster and more uniform degradation than the pure Zn (as a control group). Both the pure Zn and 4-pass as-ECAPed alloy promote formation of new bone, the mass of which increases over time. The 4-pass as-ECAPed alloy shows slightly weaker osteogenic capacity but better overall osteointegration than the pure Zn. Furthermore, both the pure Zn and 4-pass as-ECAPed alloy exhibit good in vivo biosafety.

Influence of multiple friction stir welding passes on the microstructure and mechanical properties of AA2024 age-hardened aluminum alloy

Friction stir welding (FSW) is a promising joining process for age-hardened aluminum alloys. However, when the process is used for welding age-hardened aluminum alloys, the hardness and joint efficiency are poor mainly because the strengthening precipitates become incoherent and/or get dissolved during the welding process. In this novel work, efforts have been made to enable the reprecipitation of the strengthening precipitates using multi-pass FSW. After producing FSW welds on AA2024 alloy, the welds have been processed by the same tool and at the same parameters several times to facilitate the reprecipitation of strengthening precipitates. As the precipitation kinetics of age-hardened aluminum alloys are temperature-dependent, a thermal imaging camera was utilized to record the temperature history during welding and subsequent cooling of the welded plates. The metallurgical examination of welded samples was carried out using optical microscopy, Scanning Electron Microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and microhardness test. It was observed that grain refinement occurs continuously due to dynamic recrystallization and severe plastic deformation up to the third FSW pass, after which there is no significant change in grain size. Generally, the microhardness value was higher in the stir zone than the heat-affected zone (HAZ), and the hardness in the stir zone increased after 4 passes of FSW. SEM images show clusters of incoherent precipitates, fragmentation, precipitate dispersion, dissolution, and reprecipitation of precipitates during each subsequent pass. The identification of the precipitates was carried out using EDS and XRD analysis.

Influence of Quenching Temperature on the Structure, Phase Composition, Physical and Mechanical Properties of a High-Strength Titanium Alloy of the Martensitic Class

Influence of Quenching Temperature on the Structure, Phase Composition, Physical and Mechanical Properties of a High-Strength Titanium Alloy of the Martensitic Class

Influence of Ag and Zn on the Microstructure and Properties of Sn-40 Bi Alloy for Improved Soldering Applications

Influence of Ag and Zn on the Microstructure and Properties of Sn-40 Bi Alloy for Improved Soldering Applications

Empowering the Sustainable Development of High-End Alloys via Interpretive Machine Learning.

The extensive use of scarce, expensive, and toxic elements in high-performance metal alloys restricts their sustainable development. Here we propose a novel alternative alloying-element design strategy that combines physicochemical-factor screening, a "black-box" interpretative method based on SHapley Additive exPlanation analysis, and sensitivity analyses of elemental influence. A "white-box" model of alloy compositions and properties is therefore established that enables the rational selection of abundant elements and the efficient designs of alloys with substitution for scarce alloying elements. The success of this design strategy is demonstrated by reducing the Co content in the C70350 alloy series (e.g., Cu-1.3Ni-1.4Co-0.56Si-0.03Mg (wt.%)). Indeed, Cu-1.95Ni-0.5Co-0.6Si-0.2Mg-0.1Cr (wt.%) is obtained as an ultra-low-Co-containing alloy by substituting only a trace amount of Cr for Co in the Cu-Ni-Co-Si-Mg system, followed by compositional optimization. Although the Co content is reduced by 64% (i.e., from 1.4 to 0.5 wt.%), the properties of the alloy (ultimate tensile strength and electrical conductivity of 850MPa and 47.2%IACS, respectively) are comparable to those of the C70350 alloy. This study contributes to the sustainable and green development of metallic materials by providing a new avenue for substituting abundant elements for scarce and undesired elements in metal alloys.

Nano-treating enhanced ductility and fluidity of Zn-4Al alloy

This study showcased the application of emerging nano-treating technology to improve the fluidity and properties of the Zn-4Al alloy. Our experiments showed that adding 0.5 vol% nanoparticles into the melt of Zn-4Al enhanced its fluidity by over 30% while also increasing the alloy’s ductility from 4% to 40%. Nanoparticles facilitate a refined microstructure by enhancing nucleation, restricting dendritic growth in both primary and secondary phases, and promoting a more gradual solidification process, to result in improved ductility and fluidity. The result demonstrated the significant benefits of nano-treating for Zn-4Al alloy, expanding their application range.

Laser Powder Bed Fusion Parameters Optimization for Enhanced Mechanical Properties of EOS Co-Cr Dental Alloy.

This research explores how variations in laser powder bed fusion (LPBF) parameters-laser power (P), scanning speed (v), and base plate preheating temperature (ϑp)-affect the mechanical properties of the EOS Co-Cr SP2 dental alloy. A central composite design (CCD) was used to optimize the process parameters. Mechanical testing focused on crucial properties for dental applications, including yield strength (Rp0.2), elongation (ε), toughness (KVa), and flexural strength (Rms). Microstructural analysis was conducted using light and electron microscopy, while XRD identified microstructural phases. Statistical analysis (ANOVA, Scheffé post hoc test, α = 0.05) revealed significant effects of P, v, and ϑp on the mechanical properties. Response surface models (RSMs) were developed, and optimal parameters were determined to achieve maximum toughness and flexural strength. Maximum values were obtained with laser power above 205 W and base plate preheating at 310 °C. The mathematical model predicted toughness values with less than 5% deviation from experimental results, indicating high accuracy.