Search Results (311)

Wetting behavior of molten metals on solid substrates is a critical phenomenon influencing numerous industrial applications, including welding, anti-corrosion coatings, and metal additive manufacturing (AM). In particular, molten metal jetting (MMJ), an emerging AM technology, requires that the molten metal remain pinned at the nozzle exit. Thus, each new metal requires a specific nozzle material to ensure consistent droplet ejection and deposition, making it important to rapidly identify the appropriate wetting combinations. However, traditional measurements of wetting angles require expensive equipment and only allow one combination of materials to be investigated at a time which can be time consuming. This work introduces a rapid screening method based on sessile droplet experiments to evaluate wetting profiles across multiple metal–substrate combinations simultaneously. This study investigates the wetting interactions of molten Al alloy (Al4008), Cu, and Sn on various ceramic and metal substrates to identify optimal material combinations for MMJ nozzle designs. Results demonstrate that Al4008 achieves wetting on ceramic substrates such as AlN, TiO₂, and SiC, with varying mechanisms including chemical reactions and weak surface interactions. Additionally, theoretical predictions regarding miscibility gaps and melting point differences were verified for Cu and Sn on refractory metals like Mo and W. Findings from this study contribute to the establishment of a materials compatibility library, enabling the selection of wetting/non-wetting combinations for stable MMJ operation. This resource not only advances MMJ technologies but also provides valuable insights for broader applications such as welding, coating, and printed electronics. Full article

This study investigates the fabrication and performance of a novel composite material by infiltrating SnSb11Cu6 babbitt alloy into an open-cell AlSn6Cu-SiC matrix. The composites, produced via a multi-stage liquid-state processing route, were comprehensively characterized for their microstructural, mechanical, and tribological properties. The inclusion of 5 wt.% silicon carbide reinforcement resulted in a significant improvement in tribological performance under dry-sliding conditions. Specifically, the reinforced composite exhibited a 24.8% reduction in wear and a 10.8% reduction in the coefficient of friction compared to its unreinforced counterpart. Crucially, this enhancement in wear resistance was achieved while the bulk compressive mechanical properties and ductile deformation behavior remained virtually identical to the unreinforced material. Microstructural analysis confirmed that the high-hardness SiC particles act as primary load-bearing agents, shielding the softer metallic matrix from severe wear. These findings demonstrate the successful development of a high-performance composite with enhanced tribological durability without a mechanical trade-off, making it a promising candidate for advanced bearing applications. Full article

The corrosion behavior of open-cell AlSn6Cu-based composites, one reinforced with SiC particles and the other with Al₂O₃ particles, was investigated. The composites were fabricated via liquid-state processing, employing both squeeze casting and the replication method, and they produced in two distinct pore size ranges (800–1000 µm and 1000–1200 µm). Corrosion performance was systematically evaluated through gravimetric (weight loss) measurements and electrochemical techniques, including open-circuit potential monitoring and potentiodynamic polarization tests. Comprehensive microstructural and phase analyses were conducted using X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The results revealed that both reinforcement type and pore architecture have a significant impact on corrosion resistance. Al₂O₃-reinforced composites consistently outperformed their SiC-containing counterparts, and pore enlargement generally improved performance for the unreinforced alloy and the Al₂O₃ composite but not for the SiC composite. Overall, the optimal corrosion resistance is achieved by pairing a coarser-pore architecture (1000–1200 µm) with Al₂O₃ reinforcement, which minimizes both instantaneous (electrochemical) and cumulative (gravimetric) corrosion metrics. This study addresses a gap in current research by providing the first detailed assessment of corrosion in open-cell AlSn6Cu-based composites with controlled pore architectures and different ceramic reinforcements, offering valuable insights for the development of advanced lightweight materials for harsh environments. Full article

Bronze-steel bimetallic structures are structural components finding a growing application in industrial sectors such as aerospace, power generation, and machinery. Recent legislation on green economy and sustainable manufacturing is boosting industry to implement innovative manufacturing processes and new metal alloys capable of lowering environmental footprint by avoiding toxic substances. Laser Metal Deposition is a cost-effective Additive Manufacturing technique for producing bimetallic components by limiting material waste and reducing energy consumption. In this research work, the influence of the main LMD process parameters on the final quality of CuSn₁₁Bi₃ coatings on C45 surfaces is analyzed. The Cu-based powder is specifically designed and developed to reduce environmental pollution and increase worker safety by avoiding the use of hazardous chemical elements. The performed observations demonstrate that high-density (99.90%) and crack-free clads are feasible by preventing melt pool dilution zones. Cu diffusion into the C45 substrate deteriorates the structural integrity at the clad-substrate interface by inducing liquid metal embrittlement cracking, whereas steel diffusion into the as-deposited clad promotes crack propagation. High-density (up to 99.97%) and crack-free CuSn₁₁Bi₃ coatings are achieved by using low specific energies (from 17 J/mm² to 40 J/mm²) and reducing the Oxygen content during sample manufacturing up to 0.02%. Full article

Cu-20Pb-5Sn/45 steel bimetallic composites were prepared using the solid–liquid composite method. The interfacial microstructure, bonding strength, and wear performance were systematically characterized to elucidate the mechanisms governing the solid-solution interface and copper alloy layer wear behavior. The results reveal that mutual diffusion of Cu and Fe forms a metallurgically bonded α-(Cu,Ni)/α-Fe interface with a diffusion layer thickness of approximately 10.7 µm and an interfacial shear strength of 227.58 MPa. Under dry sliding conditions, the average coefficient of friction was 0.145, with a wear rate of 7.3665 × 10⁻⁶ mm³/(N·m). The α-(Cu,Ni) matrix was reinforced by hard Cu₃P and Ni-rich phases, which resist frictional shear stresses, while dispersed Pb particles provide self-lubricating properties, while the solid-solution interface hindered dislocation propagation, reducing dislocation pile-up and ensuring stable frictional performance. Full article

Additive manufacturing techniques, such as selective laser melting (SLM), enable the production of intricate and integrated components made from metallic materials with inherent porosity. The pores, typically perceived as defects, are commonly observed on the surface or within the matrix of SLM-formed components. However, it is noteworthy that these pores can function as reservoirs for lubricants to enhance tribological performance in specific applications, such as porous bearings. In this study, the optimum conditions for fabricating Cu-15Ni-8Sn alloy porous bearings via SLM technology were investigated. By regulating laser power and hatch space during SLM processing, Cu-15Ni-8Sn alloy porous bearings were successfully obtained. The resulting oil bearings exhibited an oil content exceeding 18% and a radial crushing strength surpassing 370 MPa. At reduced laser power (80 W) and increased hatch spacing (0.9 mm), average friction coefficients of 0.1 and 0.13 were observed, with volumetric wear values of 10.3 mm³ and 96.7 mm³, respectively. The friction mechanism is a combination of abrasive wear and delamination wear. Full article

This study investigates the optimal duration for forming a uniform oxide layer and evaluates its influence on water-splitting performance. We selected a Ti₅₀Cu₃₂Ni₁₅Sn₃ amorphous ribbon, which is known to simultaneously form anatase TiO₂ and Sn oxide via a single hydrothermal process. Hydrothermal treatments were conducted at 220 °C in 150 mL of distilled water for durations of 3 and 6 h. The process successfully formed nanoscale metal oxides on the alloy surface, with the uniformity of the oxide layer increasing over time. The amorphous phase of the alloy was retained under all conditions. X-ray photoelectron spectroscopy (XPS) analysis confirmed the formation of TiO₂ and SnO_x, while Cu and Ni remained in their metallic state. Furthermore, we verified the coexistence of these oxides with metallic Ti and Sn. Photoelectrochemical analysis showed that the sample treated for 6 h exhibited the best water-splitting performance, which correlated directly with the most uniform oxide coverage. This time-controlled hydrothermal oxidation method, using only water, presents a promising and efficient approach for developing functional surfaces for electronic and photoelectrochemical applications of metallic glasses (MGs). Full article

This study investigates the optimization of hot-pressing parameters for ASP60 high-speed steel composites incorporating CuSn20 bronze alloy for use in diamond-reinforced tool applications. ASP60 and CuSn20 powders were characterized using XRD, XRF, DSC, SEM, and laser diffraction. The effects of CuSn20 addition at varying concentrations and compaction temperatures (950–1050 °C) on porosity, mechanical properties, and tribological performance were evaluated. Results showed that adding CuSn20 significantly reduced residual porosity due to its partial melting during compaction, which facilitated particle rearrangement and densification. Optimal conditions were identified at 1050 °C with 9.8 wt.% CuSn20, yielding minimal porosity (~3.7%) and the highest bending strength (374.51 ± 36.73 MPa). The optimized matrix was further reinforced with TiC-coated diamond particles at concentration c = 20, producing a composite material with excellent wear resistance, despite minor defects in the TiC coating observed on fracture surfaces. Tribological testing demonstrated that CuSn20 consistently lowered friction coefficients across all tested temperatures due to its self-lubricating properties and partial melting at elevated temperatures. Furthermore, ASP60 exhibited no measurable wear, making it a promising candidate for highly demanding applications. Overall, the study demonstrates that CuSn20 alloy enhances densification, mechanical performance, and tribological behavior of ASP60-based composites, indicating their strong potential for aggressive wire sawing and stone-cutting tool applications. Full article

For reliable electronics, it is important to have an understanding of solder joint failure mechanisms. However, because of difficulties in real-time atomistic scale analysis during deformation, we still do not fully understand these mechanisms. Here, we report on the development of an innovative in situ method of observing the response of the microstructure to tensile strain at room temperature using high-voltage transmission electron microscopy (HV-TEM). This technique was used to observe events including dislocation formation and movement, grain boundary formation and separation, and crack initiation and propagation in a Sn-3 wt.%Ag-0.5 wt.%Cu (SAC305) alloy joint formed between copper substrates. Full article

Electromigration (EM) is a critical reliability concern in electronic solder joints due to increasing current densities in modern electronic packaging. EM-induced failures often manifest as void formation and microstructural degradation, particularly at the cathode interface. To address this issue, composite solder joints with elemental additions have been explored to enhance performance under high current stress. This study investigates the effect of Zn addition on the electromigration behavior and mechanical performance of eutectic Sn-Bi solder joints on copper (Cu) and nickel-coated copper (Ni/Cu) substrates. The solder alloys 58Sn-42Bi and Zn-modified Sn-Bi were prepared and reflowed onto the substrates. Electromigration testing was performed under a constant current of 1000 mA at room temperature, with applied voltages of 5 V, 12 V, and 24 V over a 10-day period per sample. Shear tests were conducted at a crosshead speed of 0.1 mm/min to evaluate joint strength. The results revealed that Zn addition influenced the distribution of Bi within the solder matrix, reducing Bi depletion at the cathode and mitigating accumulation at the anode, suggesting improved EM resistance. Zn-containing solder joints also demonstrated enhanced shear strength compared to unmodified Sn-Bi joints. These findings highlight the potential of Zn as a beneficial alloying element for improving the reliability of lead-free solder joints and form a foundation for future studies incorporating phase analysis and predictive EM lifetime modelling. Full article

The corrosion behaviors of newly developed solder alloys with excellent mechanical properties, Sn-2.5 Ag-1.0 Bi-0.8 Cu-0.05 Ni (SABC25108N) and Sn-1.5 Bi-0.75 Cu-0.065 Ni (SBC15075N), are analyzed to supplement the corrosion behavior of the limited corrosion data in Pb- and Zn-free solder compositions. A potentiodynamic polarization test is conducted on these compositions in a NaCl electrolyte solution, the results of which are compared with those of conventional Sn-3.0 (wt%) Ag-0.5Cu and Sn-1.2Ag-0.5Cu-0.05Ni alloys. The results indicate that SBC15075N exhibits the lowest corrosion potential and highest corrosion current density, thus signifying the lowest corrosion resistance. By contrast, SABC25108N exhibits the lowest corrosion current density and highest corrosion resistance. Notably, SABC25108N shows a slower corrosion progression in the active state and exhibits the longest passive state. The difference in corrosion resistance is affected more significantly by the formation and distribution of the Ag₃Sn intermetallic compound phase owing to the high Ag content instead of by the presence of Bi or Ni. This uniform dispersion of Ag₃Sn IMC phases in the SABC25108N alloy effectively suppressed corrosion propagation along the grain boundaries and reduced the formation of corrosion products, such as Sn₃O(OH)₂Cl₂, thereby enhancing the overall corrosion resistance. These findings provide valuable insights into the optimal design of solder alloys and highlight the importance of incorporating sufficient Ag content into multicomponent compositions to improve corrosion resistance. Full article

The paper presents the results of FEM computer simulations of the drawing process on a cylindrical journal of thin-walled CuSn8 alloy tubes. This study demonstrates through FEM simulations that the drawing angle significantly affects the state of stress, strain and tool wear. Regardless of the geometry of the drawing die, greater wear was noted for the cylindrical plug. Increasing the angle of drawing die 2α from 6° to 38° contributed to a slight 5% increase in wear of the drawing dies and more than 80% increase in plug wear. Accelerated tool wear at high angles is to be associated with higher pipe pressures on the drawing die and plug. Inadequate selection of drawing geometry can cause additional material deformation effort and material fracture in the industrial drawing process of thin-walled tubes. After the drawing process, these tubes may also show non-uniform wall thickness. The optimum drawing angle for thin-walled tubes is 2α = 22°, for which about a 10% decrease in the drawing force was recorded. Full article

This study investigates the interfacial reactions of FeCoNiCr and FeCoNiMn medium-entropy alloys (MEAs) with Sn and Sn-3Ag-0.5Cu (SAC305) solders at 250 °C. The evolution of interfacial microstructures is analyzed over various aging periods. For comparison, the FeCoNiCrMn high-entropy alloy (HEA) is also examined. In the Sn/FeCoNiCr system, a faceted (Fe,Cr,Co)Sn₂ layer initially forms at the interface. Upon aging, the significant spalling of large (Fe,Cr,Co)Sn₂ particulates into the solder matrix occurs. Additionally, an extremely large, plate-like (Co,Ni)Sn₄ phase forms at a later stage. In contrast, the Sn/FeCoNiMn reaction produces a finer-grained (Fe,Co,Mn)Sn₂ phase dispersed in the solder, accompanied by the formation of the large (Co,Ni)Sn₄ phase. This observation suggests that Mn promotes the formation of finer intermetallic compounds (IMCs), while Cr facilitates the spalling of larger IMC particulates. The Sn/FeCoNiCrMn system exhibits stable interfacial behavior, with the (Fe,Cr,Co)Sn₂ layer showing no significant changes over time. The interfacial behavior and microstructure are primarily governed by the dissolution of the constituent elements and composition ratio of the HEAs, as well as their interactions with Sn. Similar trends are observed in the SAC305 solder reactions, where a larger amount of fine (Fe,Co,Cu)Sn₂ particles spall from the interface. This behavior is likely attributed to Cu doping, which enhances nucleation and stabilizes the IMC phases, promoting the formation of finer particles. The wettability of SAC305 solder on MEA/HEA substrates was further evaluated by contact angle measurements. These findings suggest that the presence of Mn in the substrate enhances the wettability of the solder. Full article

Powder metallurgy enables the production of composite materials, which are of great interest to different branches of the automotive, aerospace, and medical industries. This work investigated the sintering of an Al-xCu and Al-xCu-0.1Sn alloy, with copper concentration between 3.5 and 4.5% and tin added in the range of 0.1%. Compressibility curves were drawn, and the samples were sintered in a high-purity nitrogen-controlled atmosphere furnace. The composites were subjected to subsequent solubilization heat treatment, with cooling in low concentration polymer solutions and artificial aging (T6). The samples were studied using optical, scanning electron, Vickers microhardness, and X-ray diffraction techniques. The results indicated the effectiveness of cooling the samples after solubilization in polymer solutions, the influence of the addition of tin on the aging time, and the mechanical properties of the alloys as a function of the T6 cycles applied. Full article

This study compares the effects of adding Mo, Cu, and Sn elements on the decolorization performance of Fe₇₇Si₁₃B₉M₁ (M = Mo, Cu, or Sn) amorphous alloys. After the addition of Cu and Sn elements, the Fe-Si-B amorphous alloys generate three-dimensional (3D) petal-like nanostructured corrosion products during the decolorization process. These petal-like nanostructures possess a high specific surface area and excellent adsorption capacity, thereby effectively promoting the decolorization of dyes. Furthermore, the influence of Fe content variation on the decolorization performance of Fe_77+xSi_13−xB₉Cu₁ (x = 0, 2, or 4) and Fe_77+xSi_13−xB₉Sn₁ (x = 0, 2, or 4) alloys was investigated. The glass-forming ability of Fe_77+xSi_13−xB₉Cu₁ alloys decreases with increasing Fe content, leading to the precipitation of α-Fe crystalline phases starting from Fe₇₉Si₁₁B₉Cu₁. As the crystallinity increases, the decolorization performance of the alloys gradually deteriorates. In contrast, the Fe_77+xSi_13−xB₉Sn₁ alloys maintain their amorphous structure even with increasing Fe content, and their decolorization performance for Orange II improves accordingly. The high decolorization efficiency of FeSiBSn amorphous alloys for Orange II can be attributed to their unique self-refreshing properties. Full article