Aluminum Bronze Research Articles

Quantitative Analysis of Silicon Influence and Deformation Impact on the Mechanical and Corrosion Characteristics of Nickel Aluminium Bronze (NAB) Alloy

Nickel aluminum bronze (NAB) alloy has become increasingly popular due to its superior strength, corrosion resistance, and thermal properties. This study provides an in-depth analysis of the effect of silicon and deformation percentages on the mechanical and corrosion characteristics of NAB alloy, for marine and architectural applications. The research was carried out by systematically varying the silicon percentage (0-10%) while the percentage of deformation ranges from 0-10% at ambient temperature (32 oC), and subsequent changes in its mechanical properties and corrosion resistance were observed. Mechanical properties such as ultimate tensile strength, ductility, and hardness were evaluated using standard testing methods. The results indicated a significant correlation between the silicon percentage and the mechanical properties. Specifically, an increase in the silicon percentage was found to enhance the tensile strength from 190.7 MPa to 590.8 MPa, the ductility from 23.7% to 46.9% and the hardness from 130.5 HV to 262.4 HV values of the NAB alloy. The corrosion rate of 5.49 mm/a was obtained for the reference material containing 0% Si at 0% (X0-0) deformation, while the least corrosion rate of 9.8x10-5 mm/y was recorded for 2 wt. % Si at 10% deformation (X2-5). These findings have significant implications for the use of NAB alloy in marine and architectural applications. When the silicon percentage is optimized, the mechanical strength and corrosion resistance of the alloy are enhanced, thereby improving the durability and longevity of structures made from the developed NAB alloy

Effect of Tin Addition on the Mechanical Properties and Microstructure of Aluminium Bronze Alloyed with 4% Nickel

The current study investigates the impact of adding tin to aluminium bronze alloyed with 4% nickel on its microstructure and mechanical properties. Sand casting was chosen as the most cost-effective and efficient method of preparing the aluminium bronze alloy. Following their melting points, six distinct samples of aluminium bronze alloyed with 0% to 10% tin were added into the crucible furnace. Nickel with the highest melting point of 1453°C was added into the crucible furnace first, while tin with the lowest melting of 231.9°C was added last into the crucible furnace. The alloying components were mixed well by manually mixing the liquid for around five minutes. After sand casting, the specimens were machined, sectioned, and grounded then tests were carried out to measure their hardness, tensile strength, and impact resistance. The results of the tests indicate that the tensile strength first increases and subsequently declines as the tin addition increases. The hardness of the aluminium bronze alloy increases as the proportion of tin addition increases. The results of the investigations also demonstrate that as the hardness of the specimens increases, their impact resistance decreases and the tensile stress of each specimen increases with strain.

Single-Bubble Cavitation-Induced Pitting on Technical Alloys

Repeated single cavitation bubble experiments were performed primarily on 316L stainless steel, and some on nickel–aluminum–bronze (NAB) and pure aluminum. The bubble dynamics were recorded with two high-speed cameras and correlated with surface images, also acquired in situ. These experiments were performed for a range of stand-off distances γ (the ratio of the distance of the solid surface from the bubble to the bubble’s maximum radius) from 0.3 to 2.15. For all stand-off distances, single pits were the only surface change detected at the beginning of damage formation. Later phases of the collapse are not axisymmetric but show regions of “stronger” collapse, and the pits occur on the material underneath those regions. For γ < 0.4, the damage is attributed to the second collapse. For γ > 0.4, the first bubble collapse is most likely responsible for pitting. Shock-wave emission was detected from the collapse regions that were linked to the damage. On 316L, the pitting rate was found to be linearly dependent on the bubble radius, indicating a non-zero lower limit for the bubble radius below which pits do not occur. In terms of stand-off distance, the pitting rate (defined here as average pits per bubble) was non-monotonic, with maxima for bubbles initiated closest to the sample (γ = 0.3) and at γ = 1.4.

Comparison of the corrosion and cavitation erosion behaviors of the cast and surface-modified manganese-aluminum bronzes in sodium chloride solution

Modified layers with refined and homogenized microstructure were obtained on a cast manganese aluminum bronze (MAB) by friction stir processing (FSP) and laser surface melting (LSM). In 3.5% NaCl solution, a much more protective film was formed and uniform corrosion occurred for the two surface-modified MABs. The corrosion rate of the cast sample was reduced by a factor of 29.73% after FSP and 51.35% after LSM. The cavitation erosion (CE) rate of the cast MAB was about 1.83 and 3.07 times larger than that of the FSP and LSM samples, respectively. The CE resistance increment was highly attributed to the improved hardness and enhanced nano-indentation behavior after FSP or LSM. For each MAB, the CE resistance decreased with extended pre-immersion time. Compared with the result of the correspondingly freshly-prepared sample, the CE rate was raised by a factor of 36.22%, 42.97% and 44.00% after 30 days’ pre-immersion for the cast, FSP and LSM MABs, respectively. For the cast and FSP MABs, mechanical impact was the leading factor accounting for CE degradation. For the pre-corroded samples, corrosion damage at the β and κ phases weakened the mechanical properties and thus triggered more grievous material exfoliation under CE. For the LSM MAB, CE-corrosion synergy dominantly gave rise to the CE damage. Corrosion at grain boundaries after pre-immersion also deteriorated the CE performance. The LSM MAB possessed the highest corrosion and CE resistances because the fine single-phase microstructure reduced the galvanic corrosion effect and crack propagation tendency under CE impact.

More resource efficient recycling of copper and copper alloys by using X-ray fluorescence sorting systems: An investigation on the metallic fraction of mixed foundry residues.

According to the state of the art, most of the mixed copper and copper alloy scrap and residues are processed in a copper smelter. Despite the environmental and economic advantages relative to primary production, the recycling of copper and its alloying elements (zinc, tin, lead, nickel, etc.) requires significantly more energy and cost than remelting unmixed or pure scrap fractions such as separate collected material or production scrap. To date, however, less attention has been given to the mechanical purification of mixed scrap. Therefore, sorting by alloy-specific components (SBASC) using an industrial X-ray fluorescence (XRF) sorting system was tested on the coarse metallic fraction (10-32 mm) of mixed foundry residues. The findings show that XRF-SBASC can recover higher-grade copper concentrates (reaching 98.3% Cu), leaded brass and complex alloys, such as aluminium bronze and red brass with high purities, for the use in the production of new materials. XRF-SBASC can therefore contribute to a more resource efficient metal recycling, mainly by reducing the energy consumption and loss levels in copper metallurgy.

A novel (CuMnNi)100-xSnx medium entropy bronze alloys with excellent mechanical properties and wear resistance

Cu-Mn-Ni-based medium-entropy bronze (MEB) alloys exhibit attractive compressive strength and ductility, making them highly promising for structural applications in comparison to conventional copper alloys. Here, a series of (CuMnNi)100-xSnx (x = 0, 5, 10, 15, and 20, mass ratio) MEB alloys were fabricated using the induction melting technique, and the effects of Sn content on the phase formation, microstructure evolution, and mechanical properties were extensively studied. Additionally, the tribological properties of the MEB alloys were investigated and compared with the conventional aluminum bronze C6161 alloy. The results indicate that adding Sn element promotes the formation of body-centred cubic (BCC) phase in the MEB alloys and causes a distinct microstructure transition from the single face-centered cubic (FCC) phase to the duplex phase structure consisting of FCC and BCC. Benefiting from the solid solution strengthening induced by Sn atoms and the formation of hard BCC phase, the MEB alloys exhibit significantly enhanced hardness, yield strength, and compressive strength as the Sn content increases from 0 to 20 wt%. The wear resistance of the MEB alloys improves with increasing Sn content, surpassing that of the C6161 alloy when x exceeds 5. The competitive mechanical and tribological properties of the MEB alloys are primarily attributed to the synergistic effect between the ductile FCC phase and the hard BCC phase.

Dissimilar welding between Cu–6Al–2Ni alloy and stainless steel 316L using continuous ytterbium YAG laser

The Cu–6Al–2Ni alloy has much higher ultimate tensile strength compared to pure copper and may potentially replace it in the dissimilar joints between titanium alloys and stainless steels. Laser welding of aluminum bronze to stainless steel has not been reported in the scientific literature, which motivated the present weldability study of Cu–6Al–2Ni/316L dissimilar joint with a continuous ytterbium Yb:YAG laser. Different laser spot offsets from the joint line were selected in order to produce the joints with various dilutions of welded materials. Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) probe and X-ray diffraction (XRD) analyses of the melted zones were performed, along with microhardness measurements and tensile testing. The phase evolution in the obtained microstructures was evaluated using Thermo-Calc software. For the dilutions ranging from 23 to 63 at.% Cu, the melted zones showed globular microstructures with primary and secondary phase separation due to the miscibility gap existing in the Cu–Fe system. Lower Cu contents resulted in cellular γ-Fe structures with rare globular Cu-rich inclusions. The XRD analysis indicated the presence of ∼10% of ternary AlFe2Ni phase, however, it did not harm the mechanical properties of the welds. According to Thermo-Calc, this phase is formed from γ-Fe during the cooling process. Microhardness measurements did not indicate the embrittlement of the melted zones, which can be explained by the submicronic dispersion of AlFe2Ni. The welds exhibited a ductile fracture in Cu–6Al–2Ni at ultimate tensile strength of 350–420 MPa in a wide range of laser offsets, which is much higher than previously reported results for pure copper/316L joints.

Electropolymerized conducting polyaniline coating on nickel-aluminum bronze alloy for improved corrosion resistance in marine environment

Corrosion of metals in marine environments is a vital problem with significant negative economic impacts and coating is an effective measure of protection. In this work, polyaniline (PANI) conducting polymer was deposited as a protective layer on a nickel-aluminiumbronze (NAB) alloy using the galvanostatic electropolymerization method at different current densities. The deposited coating was characterized by various techniques such as FTIR and SEM. To evaluate its effectiveness in corrosion protection, the anticorrosion properties of different PANI coatings were evaluated in a 3.5 wt% NaCl solution by both potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The electrochemical results revealed that PANI coatings acted as a barrier towards the corrosive species and provided significant corrosion resistance to NAB degradation, with an inhibition efficiency of about 93% and a mixed-type inhibition behavior with cathodic predominance. Furthermore, corrosion protection was found to be dependent on the coated film properties and the optimum corrosion inhibition was achieved under the test conditions for films deposited at a current density of 5 mA cm-². Moreover, Raman spectroscopy confirmed the presence of the partially oxidized conductive polyaniline, the emeraldine form and its polaron structure, on the alloy surface. In addition, atomic force microscopy (AFM) was used to monitor the changes in the microstructure of the coating after exposure to the saline environment and demonstrated the formation of a robust coating with a significantly lower (5 times) surface roughness for the coated alloy than the uncoated surface after immersion. Overall results strongly support the potential of PANI for corrosion protection of the NAB alloy.

Observation of the formation of CuAl2O4 by the direct consumption of Al2O3 in an NAB alloy at elevated temperature

The oxidation behaviors of a commercial C95500 nickel aluminum bronze (NAB) alloy at elevated temperatures were investigated. The oxide scale exhibited a triplex structure with an outmost CuAl2O4 layer, an intermediate spinel-type Al2O3 layer, and a deepest nano Al2O3 film. The observation of CuAl2O4 and Al2O3 in the same grain with the same crystallographic orientation indicated that the outmost CuAl2O4 was formed by directly consuming the spinel-type Al2O3. Such a transformation process can avoid the formation of defects in the oxide scale caused by the transformation between different Al2O3 variants, attributing to the origin of the excellent oxidation resistance.

Fabrication and anti-corrosion performances of robust superhydrophobic surface on NAB via solution-etching

A labyrinth microstructure interconnected by micron and submicron acicular structures was successfully prepared by immersing nickel-aluminum bronze in 9 wt% FeCl3·6H2O solution at room temperature for 40 min. After being modified with 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (FAS-17), the microstructure surface displays robustly low-adhesion superhydrophobicity, and the water contact angle is above 160 ° on it. In addition, the superhydrophobic surface exhibits excellent corrosion resistance and stability in 3.5wt % NaCl aqueous solution and corrosion solution with different pH values.

INVESTIGATION OF THE MACHINING PERFORMANCE OF ALUMINUM–BRONZE ALLOY IN WEDM USING TAGUCHI METHOD

Aluminum–Bronze alloys (Al-10%–Cu-balance) are difficult-to-machine cut alloys. Copper (Cu) metal itself is not suitable for machining. The machining performance of the Aluminum–Bronze alloy sample was investigated by the Wire Electric Discharge Machining (WEDM) method, which is among the non-traditional manufacturing methods used in conductive materials that are difficult to process. The aluminum–bronze sample with a diameter of 20[Formula: see text]mm was cut with 0.18[Formula: see text]mm molybdenum wire electrode. Table feedrate, pulse-on-time and pulse-space were used as experimental parameters. Surface roughness and energy consumption values were measured in WEDM process. According to Taguchi analysis and ANOVA results, it was determined that the pulse-on-time parameter was effective on the surface roughness and the table feedrate parameter was effective on the energy consumption.

Corrosion mechanisms of plasma welded Nickel aluminium bronze immersed in seawater

Nickel Aluminium Bronzes (NAB) are copper-based multi-phase alloys used extensively in marine applications. NAB is vulnerable to seawater corrosion, however the interaction between its corrosion mechanisms and real-world factors including biofouling, weld microstructure and residual stress are poorly understood. Seawater corrosion tests were performed on plasma-welded NAB in laboratory and marine environments, demonstrating that the retained β’ phase in the Heat Affected Zone (HAZ) experiences Selective Phase Corrosion (SPC), whereas crevice corrosion associated with SPC of the κIII phase occurs at biofouled and stressed areas of parent material. These factors, seldom simulated in physical tests, severely impact NAB’s corrosion resistance.

Effect of Al/Ni Ratio on the Microstructure and Properties of Nickel-Aluminum Bronze Alloys.

To study the effect of aluminum and nickel elements on the microstructures and properties of the nickel-aluminum bronze (NAB) alloy, four kinds of alloys with different compositions, ZCuAl7-7-4-2, ZCuAl8-6-4-2, ZCuAl9-5-4-2, and ZCuAl10-4-4-2, are prepared by vacuum-melting technology. The effects of different Al/Ni ratios on the microstructures of NAB are investigated using a metalloscope, scanning electron microscopy, transmission electron microscopy, and XPS analysis. The mechanical property is evaluated with microhardness testing and tensile mechanical testing. The corrosion resistance is evaluated using mass-loss testing, electrochemical testing, and corrosion-product characterization. The results show that with the increase of the Al/Ni ratio, the content of precipitated phases increases, while β' and hard κ, which have a different morphology, appear. As the Al/Ni ratio rises from 1 to 2.5, the hardness increases from 104 HV to 202 HV, and the tensile strength increases by 394 MPa from 356 MPa to 751 MPa, but the elongation decreases substantially from 50.50% to 11.00%. The best corrosion resistance is shown on ZCuAl7-7-4-2, with a corrosion rate of 0.00267 mm/a after 30 d of static immersion corrosion in 3.5 wt.% NaCl solution. Through electrochemical testing and corrosion-product characterization, it is found that ZCuAl7-7-4-2 has the largest polarization resistance Rp, and the selective corrosion of the surface is mild.

Advanced cavitation erosion-corrosion resistance of nickel-aluminum bronze prepared by directed energy deposition

The mechanical properties and cavitation erosion-corrosion behavior of directed energy deposition (DED) and as-cast nickel-aluminum bronze (NAB) alloys in 3.5 wt% NaCl solution were investigated. The DED-produced NAB alloy showed a finer microstructure, and the content of κ phases significantly decreased, improving yield strength (increased by 27.76%) and elongation (increased by 54.89%) of NAB alloy. The DED-produced NAB exhibited a more uniform microstructure, fewer high-angle grain boundaries (HAGBs), and twin boundaries (∑3), resulting in a weakened synergistic effect between corrosion and mechanical attack. Compared with the as-cast counterpart, the mass loss rate of DED-produced NAB decreased by 74.77%.

Advancements in Additive Manufacturing for Copper-Based Alloys and Composites: A Comprehensive Review

Copper-based materials have long been used for their outstanding thermal and electrical conductivities in various applications, such as heat exchangers, induction heat coils, cooling channels, radiators, and electronic connectors. The development of advanced copper alloys has broadened their utilization to include structural applications in harsh service conditions found in industries like oil and gas, marine, power plants, and water treatment, where good corrosion resistance and a combination of high strength, wear, and fatigue tolerance are critical. These advanced multi-component structures often have complex designs and intricate geometries, requiring extensive metallurgical processing routes and the joining of the individual components into a final structure. Additive manufacturing (AM) has revolutionized the way complex structures are designed and manufactured. It has reduced the processing steps, assemblies, and tooling while also eliminating the need for joining processes. However, the high thermal conductivity of copper and its high reflectivity to near-infrared radiation present challenges in the production of copper alloys using fusion-based AM processes, especially with Yb-fiber laser-based techniques. To overcome these difficulties, various solutions have been proposed, such as the use of high-power, low-wavelength laser sources, preheating the build chamber, employing low thermal conductivity building platforms, and adding alloying elements or composite particles to the feedstock material. This article systematically reviews different aspects of AM processing of common industrial copper alloys and composites, including copper-chrome, copper-nickel, tin-bronze, nickel-aluminum bronze, copper-carbon composites, copper-ceramic composites, and copper-metal composites. It focuses on the state-of-the-art AM techniques employed for processing different copper-based materials and the associated technological and metallurgical challenges, optimized processing variables, the impact of post-printing heat treatments, the resulting microstructural features, physical properties, mechanical performance, and corrosion response of the AM-fabricated parts. Where applicable, a comprehensive comparison of the results with those of their conventionally fabricated counterparts is provided.

Anti-Corrosion Effects of Aluminum Bronze Film Coatings and Cathodic Disbondment Resistance of Coating Films

Anti-Corrosion Effects of Aluminum Bronze Film Coatings and Cathodic Disbondment Resistance of Coating Films

Experimental analysis for optimization of process parameters in machining using coated tools

Manufacturers are facing challenges in achieving high productivity and quality in manufacturing through machining. PVD-coated tools can control several machining challenges by enhancing hardness and abrasion resistance of the cutting tool. These tools facilitate turning operations in terms of efficiency, accuracy, and productivity by extending cutting performance and tool life. Aluminum bronze, a copper alloy valued for its mechanical, thermal, corrosion, and wear-resistant properties, finds application in diverse industries such as aerospace, automobile, marine, and electrical engineering, as well as in the creation of sculptures, decorative elements, and thermal devices. However, machining aluminum bronze presents common challenges, including achieving a smooth surface finish and minimizing high cutting force due to its inherent strength and abrasiveness. This research aims at identifying the optimal levels of cutting velocity, feed, and depth of cut to minimize surface roughness and cutting force during dry turning of wear-resistant high-strength CuAl10Fe5Ni5-C. PVD AlTiN-coated tools were utilized, which offer many advantages over others. Experiments were conducted through Taguchi’s L27 OA (orthogonal array) of factors. The results indicate that coated tools have superior performance in reducing surface roughness and cutting force. When it comes to designing and optimizing experiments, integrating PCA with Taguchi method is a potent strategy. Again, it was observed that feed is the most influential factor affecting responses.

Biofouling and corrosion rate of welded Nickel Aluminium Bronze in natural and simulated seawater

Updated understanding on the effect of biofouling on corrosion rate is needed to protect marine structures as climate change is altering seawater physiochemistry and biofouling organism distribution. Multi-disciplinary techniques can improve understanding of biofouling development and associated corrosion rates on metals immersed in natural seawater (NSW). In this study, the development of biofouling and corrosion on welded Nickel Aluminium Bronze (NAB) was investigated through long-term immersion tests in NSW, simulated seawater (SSW) and air. Biofouling was affected by geographic location within the marina and influenced corrosion extent. The corrosion rate of NAB was accelerated in the initial months of exposure in NSW (1.27 mm.yr−1) and then settled to 0.11 mm.yr−1 (annual average). This was significantly higher than the 0.06 mm.yr−1 corrosion rate measured in SSW, which matched published rates. The results suggest that corrosion rates for cast NAB should be revised to take account of biofouling and updated seawater physiochemistry.

Effect of liquid nitrogen cryogenic cooling during wire arc directed energy deposition of nickel aluminum bronze

Effect of liquid nitrogen cryogenic cooling during wire arc directed energy deposition of nickel aluminum bronze

Effect of seawater salinity on the fretting corrosion behavior of nickel-aluminum bronze (NAB) alloy

In industrial applications, components made by Nickel-aluminum bronze (NAB) alloys are commonly encountered by fretting corrosion. This study aims to investigate the effect of seawater salinity on fretting corrosion behavior of the material. Research indicates that due to the synergistic effect of wear and corrosion, both the friction force and wear volume reach the peak value under the salinity of 3.5%. The reduction in wear observed when the salinity increases from 3.5% to 7.5% can be attributed to the hydrolysis of water-soluble CuCl2 to produce Cu2O, which reduces the corrosion degree and provides a lubrication effect. Furthermore, the combination of chloride ions and aluminum leads to the formation of an AlCl3 passivation layer, which serves to protect the alloy surface.