Addition Of Zn Research Articles

Sodium Promoted FeZn@SiO2-C Catalysts for Sustainable Production of Low Olefins by CO2 Hydrogenation

A prepared FeZnNa@SiO2-C catalyst with graphitized carbon (C)-modified mesoporous SiO2 supports metal nanoparticles with the sol–gel method. The effect of adding metal Na and Zn promoters as a dispersion on the CO2 hydrogenation to low olefins was systematically studied. The results showed that Zn–Na, as a combination, could promote the absorption of CO2 and improved the conversion rate of CO2. Na as an alkaline substance can improve the absorption of more acidic CO2, which could increase the conversion rate of CO2 to 59.03%. Meanwhile, the addition of secondary metal Zn to Fe-based catalysts to form a surface alloy could alter the adsorption of CO2 and the activation of C-O bonds, inhibit the subsequent hydrogenation of olefins to paraffins, and facilitate the reduction of Fe2O3 and the formation of active Fe5C2 species. The formation of active Fe5C2 species was found in TEM and XRD, and the selectivity of the target product was 41.07%. The deep hydrogenation of olefins was inhibited, and the space–time yield (STY) of low olefins was raised again by inhibiting their deep hydrogenations, up to 0.0436. However, the corresponding STY did not increase infinitely with the increase of Na doping, and higher catalytic performance for CO2 hydrogenation could be exhibited when the Na doping reached 6.4%. Compared with Fe@SiO2-C catalyst, Na- and Zn-promoted Fe-based catalysts, prepared by the modified sol-gel method, can be used directly for highly efficient CO2 hydrogenation to low olefins and thus has a more promising application prospect in the future.

Coercivity enhancement with reduced Tb usage for NdFeB sintered magnets by grain boundary diffusion with multicomponent Tb-Ce-Al-Cu-Zn alloy powders

In this work, coercivity enhancement and thermal stability improvement for NdFeB sintered magnets by grain boundary diffusion (GBD) with Tb75Cu25-xZnx (x = 0–25) alloy powders are investigated. The coercivity (iHc) is enhanced from 10.6 kOe to 19.5–22.5 kOe by GBD with Tb75Cu25-xZnx (x = 0–25). Proper Zn addition into diffusion source can further improve the coercivity and its thermal stability for NdFeB sintered magnets. Besides, the costs of the diffusion sources have been significantly reduced by multicomponent Tb75-y-zAlyCez (Cu, Zn)25 alloy powders, and nearly without sacrificing the magnetic properties. Coercivity is significantly increased to 20.3–22.1 kOe by GBD with Tb75-yAlyCu20Zn5 (y = 0–30) alloy powders, and large coercivity increment (ΔiHc) of 11.0–11.5 kOe is found for y = 0–30. To further reduce the Tb usage, Tb45-zCezAl30Cu20Zn5 (z = 0–25) alloy powders are adopted as diffusion sources. Although the ΔiHc is gradually decreased as Ce content increases, the large coercivity of 18.4–21.6 kOe can be attained for z = 0–25. The formation of (Nd, Tb)2Fe14B shells can inhibit the nucleation of reverse domain. While Ce, Al, Cu and Zn prefer to distribute at grain boundary and triple junction, which can strengthen the decoupling effect between adjacent grains. Both effects contribute to the large coercivity enhancement. The optimized magnetic properties of iHc = 20.5 kOe, ΔiHc = 9.9 kOe and (BH)max = 49.1 MGOe can be achieved for the magnet GBD with Tb30Ce15Al30Cu20Zn5 alloy powders.

Intermetallic compound evolution and mechanical properties of Sn-0.7Cu-0.1Ni-xZn lead-free solder alloys prepared by directional solidification

The addition of Ni and Zn is known to improve the properties of Sn-0.7Cu solder. However, previous research has only focused on the improvement of Sn-0.7Cu solder performance through microalloying methods, and the impact of preparation processes and microalloying on the properties of Sn-0.7Cu solder remains unclear. In this study, Sn-0.7Cu-0.1Ni-xZn solders were prepared using the directional solidification (DS) method. DS eliminates transverse grain boundaries, making it an advantageous method to study the effect of Zn content on the mechanical properties of Sn-0.7Cu-0.1Ni solder. The results showed that some CuZn intermetallic compounds (IMCs) and Cu6Sn5 IMCs transformed into Cu5Zn8 IMCs of better mechanical properties and (Cu,Ni)6(Sn,Zn)5 IMCs of more thermodynamic stability with the increase of Zn content. The tensile results indicated that the ultimate tensile strength (UTS) and yield strength (YS) of the solders followed the same pattern as the Zn content increased. Additionally, the fracture elongation (EL) of the solders initially increased and then decreased with the increase of Zn content. The peak EL was observed at 21.9% when the Zn content was 0.5 wt%. Finally, the fracture surface analysis of the tensile specimens revealed that the solder deformation was primarily plastic, with a small degree of necking observed.

Zinc attenuates arsenic overdose-induced brain damage via PERK/ATF6 and TLR/MyD88/NF-κB pathways

Exposure to arsenic (As), a widespread non-metallic toxicant in nature, often results in neurotoxicity, although the exact mechanism is unknown. Zinc (Zn) is a powerful nutrient often thought to be beneficial for growth, development and immunity. Whether Zn can rescue brain damage caused by As contamination remains to be demonstrated. Therefore, in this study, a 30-day model of As poisoning (2.83 mg/L) in carp was established and treated with Zn (1 mg/L) to investigate the detoxification mechanism involved. Histological observations showed that As induced the loosening of the molecular layer structure of the cerebellum and the dissolution or even disappearance of nuclei, accompanied by the occurrence of microthrombi in the granular layer, and the addition of Zn attenuated such As-induced damage. Further mechanistic studies indicated that Zn ameliorated As exposure-induced abnormalities in antioxidant capacity (decreased CAT and Cu/Zn-SOD), activation of the Nrf2/keap1 pathway and endoplasmic reticulum stress (ERs), which is a key factor in As-induced brain damage. ERs (high expression of PERK, ATF6, CHOP, eiF2α and GRP78) and inflammation (overexpression of TLR2, TLR4, MyD88, IKK, NF-κB, IL-1β and IL-6 and low expression of IκBα and IL-10). We suggest that Zn can alleviate excessive As-induced brain damage by attenuating As-induced oxidative stress, PERK/ATF6 and TLR/MyD88/NF-κB pathways. The present study fills in the preventive mechanism of As injury in fish and provides the possibility of prevention and control of As pollution-induced brain tissue injury by Zn rescue.

Effect of Zn addition on the stress corrosion cracking of as-cast BCC Mg-11Li based alloys

The stress corrosion cracking (SCC) of ultralight Mg-11Li alloys with different Zn content revealed the obvious SCC sensitivity of mechanical ductility, while the mechanical strength is minimal. The less Zn (1 wt. %) addition can improve SCC resistance, while none (1 wt. %) or massive Zn (3, 6 wt. %) addition presents the opposite effect. The lowest SCC sensitivity of Mg-11Li alloy with 1 wt. % Zn is determined by the excellent surface film and insignificant micro-galvanic effect, while elevating Zn will enhance SCC sensitivity due to the considerable micro-galvanic effect induced by cathodic second phase and anodic β-Li matrix.

Atomic Structure of Hardening Precipitates in Al-Mg-Si Alloys: Influence of Minor Additions of Cu and Zn.

Shifting toward sustainability and low carbon emission necessitates recycling. Aluminum alloys can be recycled from postconsumer scrap with approximately 5% of the energy needed to produce the same amount of primary alloys. However, the presence of certain alloying elements, such as copper and zinc, as impurities in recycled Al-Mg-Si alloys is difficult to avoid. This work has investigated the influence of tiny concentrations of Cu (0.05 wt %) and Zn (0.06 wt %), individually and in combination, on the precipitate crystal structures in Al-Mg-Si alloys in peak aged and overaged conditions. To assess whether such concentrations can affect the hardening precipitate structures, atomic resolution high-angle annular dark-field scanning transmission electron microscopy and atom probe tomography were adopted. The results indicate that low levels of Cu or Zn have a significant influence. Both elements showed a relatively high tendency to incorporate into precipitate structures, where Cu occupies specific atomic sites, creating its own local atomic configurations. However, Zn exhibited distinct behavior through the formation of extended local areas with 2-fold symmetry and mirror planes, not previously observed in precipitates in Al-Mg-Si alloys. Incorporation of Cu and/or Zn will influence the precipitates' electrochemical potential relative to matrix- and precipitate-free zones and thus the corrosion resistance. Furthermore, the presence of Cu/Zn structures (e.g., β'Cu, Q'/C) enhances the thermal stability of these precipitates and, accordingly, the mechanical properties of the material. The results obtained from this work are highly relevant to the topic of recycling of aluminum alloys, where accumulation of certain alloying elements is almost unavoidable; thus, tight compositional control might be critical to avoid quality degradation.

Effect of a Zn interlayer on the formation mechanism and mechanical performance of AA6061/DP590 steel resistance riveting welding

This study focuses on the forming mechanism of resistance riveting welding joints of 6061 Al alloy and DP590 steel plate and the effect of adding Zn interlayer on the mechanical properties of the joints. During the piercing stage, the rivet pierces through the Al plate, the Al plate beneath the rivet melts and reacts with the steel, with intermetallic compounds (IMC) generated. Some of the melted Al and IMCs are squeezed onto the side of the rivet. In the process of adding the Zn interlayer, the Zn is gradually incorporated into the melted Al near the rivet during the piercing process. At the welding stage, as the current is increased, the nugget diameter, peak joint load, and energy absorption values gradually increase. The failure mode of the joint changes from an interfacial fracture to pull-out fracture, eventually changing to base material pull-off, as the welding current increases. Compared to joints without Zn addition, joints with Zn addition exhibit a smaller nugget diameter, and narrower IMC layers at the interface. At a welding current of 13 kA, because the failure mode was a shear fracture of the nuggets, the peak joint load of the joints with zinc added decreased by 215 N compared to the unadded ones. On the contrary, when the current increased to 14 kA, the peak joint load of the joints was elevated by 639 N, because the IMC layer and the aluminum plate became the main load-bearing locations.

Zn Doping Improves the Anticancer Efficacy of SnO2 Nanoparticles

Tin dioxide (SnO2) nanoparticles (NPs) can be applied in several ways due to their low cost, high surface-to-volume ratio, facile synthesis, and chemical stability. There is limited research on the biomedical application of SnO2-based nanostructures. This study aimed to investigate the role of Zn doping in relation to the anticancer potential of SnO2 NPs and to enhance the anticancer potential of SnO2 NPs through Z doping. Pure SnO2 and Zn-doped SnO2 NPs (1% and 5%) were prepared using a modified sol–gel route. XRD, TEM, SEM, EDX, UV-Vis, FTIR, and PL techniques were used to characterize the physicochemical properties of produced NPs. XRD analysis revealed that the crystalline size and phase composition of pure SnO2 increased after the addition of Zn. The spherical shape and homogenous distribution of these NPs were confirmed using TEM and SEM techniques. EDX analysis confirmed the Sn, Zn, and O elements in Zn-SnO2 NPs without impurities. Zn doping decreased the band gap energy of SnO2 NPs. The PL study indicated a reduction in the recombination rate of charges (electrons/holes) in SnO2 NPs after Zn doping. In vitro studies showed that the anticancer efficacy of SnO2 NPs increased with increasing levels of Zn doping in breast cancer MCF-7 cells. Moreover, pure and Zn-doped SnO2 NPs showed good cytocompatibility in HUVECs. This study emphasizes the need for additional investigation into the anticancer properties of Zn-SnO2 nanoparticles in various cancer cell lines and appropriate animal models.

Effect of alloying elements on interfacial properties and mechanical behavior of Mg/WC systems: A first-principles study

Alloying elements play a key role in the interfacial stability and mechanical properties of WC reinforced Mg matrix composites while their influence is complex and unclear. In this work, the segregation energy, adhesion work, interface energy and tensile strength of Mg(0001)/WC(0001) interface alloying with Al, Si, Zn, Zr, Ca, La, Mn, Sc, Y and Sn were calculated by first-principles method and the strengthening and fracture mechanism of the interface were clarified. The results show that alloying elements such as Al, Si, Zr, Ca, La, Mn, Sc and Y increase the adhesion work and reduce the interface energy, thereby improving the interface stability. Meanwhile, the addition of Sn and Zn shows the opposite effect. Multiple regression analysis indicates that the valence electrons and electronegativity of alloying elements have the most significant effect on the thermodynamic parameter and a high-accuracy prediction regression equation is put forward. The fracture of the Mg/WC interface occurs in the Mg matrix side but not on the exact interface. This may result from the strong M−C (M = Al, Si) bonds at the interface and weak Mg-Mg bond in the bulk according to COHP analysis.

Effect of Zn Addition on the Microstructures and Mechanical Properties of Extruded Mg-1Al-0.3Ca-0.3Mn Magnesium Alloys

Effect of Zn Addition on the Microstructures and Mechanical Properties of Extruded Mg-1Al-0.3Ca-0.3Mn Magnesium Alloys

Effect of Frequency and Rate of Zinc Application on Nodulation, Chlorophyll Content, Yield, and Quality of Soybean Grown in a Vertisol of Jabalpur, Madhya Pradesh, India

Zinc (Zn) fertilizer is commonly used in nutrient intensively cultivated deficient soils of central, India. Zn is a structural components of plants. However, little is known, on optimum dose of Zn especially in a vertisol of Jabalpur district. This study was required to find out Zn dose for sustainable productivity and maintenance of soil fertility. The study comprised of three frequency levels, Zn application in 1st year only, Zn application in alternate year, and Zn application in every years and five rates of Zn, (0, 2.5, 5.0, 7.5, and 10.0 kg Zn ha-1) was applied in Kharif season. The result of analysis revealed that the highest symbiotic traits viz., nodule number of 36.78, fresh and dry weight (1.09 and 0.31 g plant-1) were found with application of 5 kg Zn ha-1 at 45 DAS at alternate year. The highest SPAD score of 44.98 and relative water content of 62.41 % was recorded with 5 kg Zn ha-1 at 60 DAS and found significant at alternate year. The Zn addition @ 5.0 kg ha⁻¹ through ZnSO4.7H2O to soybean in alternate year which increased by 1.28 to 1.53 (19.53 %) over only single year Zn addition. This was the best practice in a typic haplusterts as it resulted in an average production of 1.54 t ha-1 of seed yield ha⁻¹ over no zinc application (1.24 t ha-1) which increased by 24.19 %. The zinc application improved quality of seed in terms of oil and protein over control. So it was concluded that Zn application at alternate year and 5 kg Zn ha-1 for increasing yield and quality of soybean in a vertisol of Jabalpur district.

Nucleation-promoting effect of mixed Zn and ZnO particles on tetra-n-butylammonium bromide hydrate

Tetra-n-butylammonium bromide (TBAB) hydrate is an ionic semi-clathrate hydrate, and it can be used as an energy-storage and gas-separation medium. Nucleation of TBAB hydrate is unlikely to occur and this characteristic causes problems in the refrigeration system due to the need for excessive cooling and delays in gas separation due to the slow formation. Therefore, a technique for rapid formation of TBAB hydrate is required. In a previous study, it was found that addition of mixed and ground Zn and ZnO particles (Zn–ZnO) to TBAB aqueous solution significantly promoted nucleation of TBAB hydrate. Since the nucleation of TBAB hydrates was effectively promoted by the very simple addition of Zn–ZnO, this technique can be easily applied to conventional systems. However, the nucleation-promoting mechanism have not been clarified. The clarification of the nucleation-promoting effect of Zn–ZnO on TBAB hydrates is important to elucidate the nucleation-promoting mechanism of clathrate hydrates by the addition of substances. Therefore, the objective of the present study was to investigate the nucleation-promoting mechanism of Zn–ZnO on TBAB hydrate. Experimental results showed that immersion of Zn–ZnO in TBAB aqueous solution reduced the nucleation-promoting effect, but a decrease in the nucleation-promoting effect was not observed when Zn–ZnO was immersed in water. Microscopy observation confirmed that immersion of Zn–ZnO in TBAB aqueous solution had little effect on its surface morphology, but X-ray diffraction and X-ray photoelectron spectroscopy indicated formation of solid TBAB on Zn–ZnO. Zn–ZnO did not show a significant nucleation-promoting effect on tetrahydrofuran hydrate, which is a non-ionic clathrate hydrate. This suggest that Zn–ZnO has properties that attract tetra-n-butylammonium and Br ions, and that the proximity of these ions may promote formation of TBAB hydrate. It was also suggested that the mechanism of nucleation promotion by the addition of substances is different for ionic clathrate hydrates and non-ionic clathrate hydrates.

Microstructure, texture, and mechanical properties of multi-pass cold drawn Mg–xZn alloy wire

We performed multiple-pass cold drawing for Mg-4.0 wt%Zn (Z4) and Mg-6.0 wt%Zn (Z6) which showed a preferable drawing deformability of ∼76 and 69 % accumulative true strain (ATS), respectively, at room temperature. Zn addition into pure Mg caused the microstructure refinement and the strengthening of Mg alloy, while the ductility of Mg alloys decreased with increasing Zn content. Moreover, the microstructure of as-drawn Z4 wire with larger ATS showed fibrous morphology, and the grains were elongated along the drawing direction (DD) but the grain boundaries could still be distinguished in wires of Z6 alloy. Based on texture analysis, the non-basal texture of Z4 and Z6 gradually increased with cold drawing. Eventually, the texture component of both Z4 and Z6 wires transformed from as-extruded basal texture to obvious <101¯0> fiber texture with <101¯0> parallel to the DD. The difference was that, besides the formation of a main basal texture, a weaker non-basal texture also appeared in as-extruded Z6 alloy with a higher Zn content. The addition of Zn promoted the formation of non-basal texture.

Role of Zn addition on the microstructure and tensile property in Mg–Mn–Nd alloys

The role of Zn addition (1, 2 wt%) on the microstructural characteristics and tensile properties of the extruded Mg–1Mn–1Nd (MN11) alloy is discussed. The addition of Zn negligibly influences the particle type; however, Zn addition causes un–homogeneous distribution structure firstly and then develops homogeneous structure because of the change of size and distribution of Mg12Nd particles. The MZN111 sheet shows higher yield strength (YS) along the extrusion direction (ED), and lower YS along the transverse direction (TD), compared to the MN11 sheet. This improvement is attributed to the Zn solute atoms via solid-solution strengthening effect, while the reduction is ascribed to the formation of TD–orientation texture and coalescence of dynamic recrystallized (DRXed) grains. As the Zn content increases to 2 wt%, The MZN121 sheet with highest strength can be ascribed to the homogeneous distribution of finest grains via the grain–boundary strengthening effect and more Zn solute atoms via solid–solution strengthening effect. The increased size of Mg12Nd particles with 1 wt% Zn content and coalescence of DRXed grains, which can significantly reduce the ductility of MZN111 sheet. Further, the ductility enhancement of the MZN121 sheet is mainly due to the homogeneous distribution of fine grains and homogeneous alignment of Mg12Nd particles.

Comparison of effect of CdS QD and ZnS QD and their corresponding salts on growth, chlorophyll content and antioxidative capacity of tomato

When applied in the same concentration to tomato plants, cadmium sulfate (CdSO4) and zinc sulfate (ZnSO4) were transported from soil to roots and from roots to shoots more readily than their nano counterparts: cadmium sulfide quantum dots (CdS QD) and zinc sulfide quantum dots (ZnS QD). Compared to the CdS QD, he higher rate of transport of CdSO4 resulted in a greater negative effect on growth, chlorophyll content, antioxidant properties, lipid peroxidation and activation of antioxidant defence systems. Although ZnSO4 was transported more rapidly than ZnS QD, the overall effect of Zn addition was positive (increase in total plant mass, stem length, antioxidant content and decrease in lipid peroxidation). However, these effects were more pronounced in the case of ZnS QD, suggesting that the mechanisms underpinning the activity of ZnS QD and ZnSO4 were different. Thus, the risk of phytotoxicity and food chain transfer of the two elements depended on their form (salt or nanoform), and consequently their effects on plants’ growth and physiology were different.

Fabrication and Characterization of Zn Particle Incorporated Fibrous Scaffolds for Potential Application in Tissue Healing and Regeneration.

Zinc (Zn) metal and its alloys have received a lot of interest in biomedical applications due to their biodegradability, biocompatibility, antimicrobial activity, and ability to stimulate tissue regeneration. Bulk Zn has been successfully utilized in a variety of implant applications, most notably as bioabsorbable cardiac stents and orthopedic fixation devices, where it provides adequate mechanical properties while also releasing helpful Zn ions (Zn2+) during degradation. Such beneficial ions are dose-dependent and, when released in excess, can induce cellular toxicity. In this study, we hypothesize that embedding Zn metal particles into a polymer nanofibrous scaffold will enable control of the degradation and time release of the Zn2+. We designed and fabricated two polymer scaffolds, polycaprolactone (PCL) and polycaprolactone-chitosan (PCL-CH). Each scaffold had an increasing amount of Zn. Several physicochemical properties such as fiber morphology, crystallinity, mechanical strength, hydrophilicity, degradation and release of Zn2+, thermal properties, chemical compositions, and so forth were characterized and compared with the PCL fibrous scaffold. The biological properties of the scaffolds were evaluated in vitro utilizing direct and indirect cytotoxicity assays and cell viability. All the data show that the addition of Zn changed various physical properties of the PCL and PCL-CH scaffolds except their chemical structure. Further investigation reveals that the PCL-CH scaffolds degrade the Zn particles relatively faster than the PCL because the presence of the hydrophilic CH influences the faster release of Zn2+ in cell culture conditions as compared to the PCL fibrous scaffold. The combined advantages of CH and Zn in the PCL scaffold enriched 3T3 fibroblast cells' survival and proliferation except the ones with the higher concentration of Zn particles. These new composite scaffolds are promising and can be further considered for tissue healing and regeneration applications.

Development of a Ratiometric Fluorescent Cu(II) Indicator Based on Poly(N-isopropylacrylamide) Thermal Phase Transition and an Aminopyridyl Cu(II) Ligand.

An aqueous Cu2+ and Zn2+ indicator is reported based on copolymerizing aminopyridine ligands and the environment-sensitive dansyl fluorophore into the responsive polymer poly(N-isopropylacrylamide) (PNIPAm). The metal ion binding creates charge and solvation that triggers PNIPAm's thermal phase transition from hydrophobic globule to hydrophilic open coil. As a basis for sensing the metal-binding, the dansyl fluorescence emission spectra provide a signal at ca. 530 nm and a signal at 500 nm for the hydrophobic and hydrophilic environment, respectively, that are ratiometrically interpreted. The synthesis of the title pyridylethyl-pyridylmethyl-amine ligand (acronym PEPMA) with a 3-carbon linker to the copolymerizable group, aminopropylacrylamide (PEPMA-C3-acrylamide), is reported, along with a nonpolymerizable model ligand derivative. The response of the polymer is validated by increasing temperature from 25 °C to 49 °C, which causes a shift in maximum emission wavelength from 536 nm to 505 nm, along with an increase in the ratio of emission intensity of 505 nm/536 nm from 0.77 to 1.22 (λex = 330 nm) as the polymer releases water. The addition of divalent Cu or Zn to the indicator resulted in a dansyl emission shift of 10 nm to a longer wavelength, accompanied by fluorescence quenching in the case of Cu2+. The addition of EDTA to the Cu2+-loaded indicator reversed the fluorescence shift at 25 °C to 35 °C. The affinities of Cu2+ and Zn2+ for the PEPMA derivatives are log Kf = 11.85 and log Kf = 5.67, respectively, as determined by potentiometric titration. The single-crystal X-ray structure of the Cu2+-PEPMA derivative is five-coordinate, of-geometry intermediate between square-pyramidal and trigonal-bipyramidal, and is comparable to that of Cu2+ complexes with similar formation constants.

Layered double hydroxides modified by transition metals for sustainable glycerol valorization to glycerol carbonate

The surplus of glycerol generated as a by-product in biodiesel production increased interest in the investigation of the catalytic conversion of this platform molecule into valuable chemical products, such as glycerol carbonate. Therefore, the catalytic transesterification of glycerol and dimethyl carbonate for the synthesis of glycerol carbonate was studied using Cu-Zn-Mg-Al mixed oxide catalysts with different Cu-Zn atomic ratios. Layered double hydroxides were the precursors materials to obtain multi metallic oxides. They were synthesized by coprecipitation. The materials were physico-chemically characterized by XRD, MP-AES, N2 sorption, SEM, XPS and TPD-CO2. The addition of Cu and Zn to the Mg and Al matrix improved the catalytic behaviour of the solid materials. First, the highest glycerol carbonate yield was reached with the catalyst with the highest Zn load at 70 °C for 90 min. This result was taken as a basis to modify parameters and find the optimal reaction conditions. They were a temperature of 85 °C, a reaction time of 270 min, a DMC:glycerol molar ratio of 2:1, solvent free and 7.5 wt% of catalyst. The highest yield obtained (82%) was attributable to the synergistic effect of the Cu-Zn load promoted by an adequate distribution of basicity and textural properties. The reuses of the best catalyst were also investigated.

Effect of Zinc (Zn) addition on Impact and Hardness Properties of Aluminium (Al) scrap

Effect of Zinc (Zn) addition on Impact and Hardness Properties of Aluminium (Al) scrap

Design of novel Al-Mg-(Zn-Sc) alloys with enhanced mechanical properties and corrosion resistance

The novel Al-Mg-(Zn-Sc) alloys were fabricated using vacuum induction melting and argon-protected casting method. The effects of Zn and Sc on the microstructure evolution, mechanical properties and corrosion properties of the as-cast Al-Mg-(Zn-Sc) alloys were comparatively studied. The results show that the addition of 1.5 wt% Zn facilitates the evolution of coarsen β-Al3Mg2 phases into fine T-Mg32(Al, Zn)49 phases, enhancing the resistance to intergranular corrosion (IGC) of Al-5.5Mg-1.5Zn-0.4Sc (alloy 4) with a maximum corrosion depth of 133.4 µm. The addition of Zn also promotes Mg solid solution, resulting in a 13.7 % increase in Mg solid solution concentration in Al-5.5Mg-1.5Zn (alloy 3) compared to Al-5.5Mg (alloy 2). The addition of 0.4 wt% Sc leads to the formation of smaller (∼2 µm) Al3Sc particles with a larger volume fraction of 0.96 %, providing grain refinement and improved strength in the Al-Mg alloy. Furthermore, the joint addition of Zn and Sc elements reduces the grain size by 64.0 % compared to Al-5.0Mg (alloy 1) and increases the tensile strength by 33.5 %. Alloy 4 exhibits the greatest measured tensile strength of 343 MPa. The solid solution strengthening, grain boundary strengthening and precipitation strengthening contributions to alloy 4 are calculated at 76.8 MPa, 27.9 MPa and 66.6 MPa, respectively.