Effect Of Ni Content Research Articles

Effect of Ni on the mechanical and corrosion properties of TiC-reinforced steel matrix composites

Particle-reinforced steel matrix composites typically lead to a decrease in corrosion resistance while enhancing mechanical properties. However, steel matrix composites for marine applications require superior mechanical properties and corrosion resistance. In this study, 8 vol% TiC/Fe–C composites were prepared using the master alloy method. The effects of Ni contents (0, 1.2 wt%, 1.6 wt%, 2.0 wt%, and 2.4 wt%) on the mechanical and corrosion properties of the composites were evaluated. Results indicated that the tensile strength, elongation, and corrosion resistance of the composites initially increased and then decreased with increasing Ni content. The σUTS and εf of Ni2.0 composites increased from 536 MPa and 4.1 % for Ni0 to 1100 MPa and 9.0 %, respectively. The icorr and corrosion rate of the Ni2.0 composite were 0.440 μA/cm2 and 0.0057 mm/year, respectively. The mechanical properties and corrosion resistance of TiC particle-reinforced steel matrix composites were simultaneously enhanced by the addition of 2.0 wt% Ni. The increase in strength is mainly attributed to changes in thermal mismatch resulting from Ni addition, solid solution strengthening of the Fe–Ni solid solution, and improved interface compatibility between the TiC particles and the matrix, thus enhancing load transfer efficiency. The increase in plasticity can be attributed to the significant improvement in interface deformation compatibility with Ni addition. The increase in corrosion resistance primarily results from the steel matrix alloying, uniform distribution of TiC particles, and strong interface bonding between the particles and the matrix.

Laser irradiation induced CoNi@carbon composites as high-performance microwave absorbers

Metal-organic-frameworks (MOFs) derivatives, known for their lightweight and high-performance properties, are highly sought after as microwave absorbers. However, most reported MOFs derived absorbers are pyrolyzed in tube furnaces, which is time-consuming and difficult to finely tune the microstructure due to the low heating-quenching process. In this study, laser irradiation was used as a heat source to pyrolyze CoNi ZIF. By controlling the irradiation power (30 mW, 50 mW), Co/C composites were obtained in just a few seconds, with Co nanocrystals ranging from 10 to 50 nm. The presence of Ni could modulate the microstructure and electric-magnetic parameters of Co/C composites. The effects of Ni content and irradiation power on the electromagnetic absorption properties of Co/C were analyzed. Considering the enhanced dipolar/interfacial polarization, matched impedance, and strong magnetic coupling network, a minimum reflection loss of −45 dB with the effective absorption bandwidth of 6 GHz can be achieved by Co/C at the thickness of 2 mm. Additionally, the laser irradiation was performed in air atmosphere, providing an effective way for industrial production of high-efficiency and broadband wave-absorbing materials.

Effect of Ni content on 475°C embrittlement of directed energy deposited duplex stainless steel using a laser beam and wire feedstock

Duplex stainless steel (DSS), specifically the 2209 grade, is increasingly employed in additive manufacturing, particularly in processes like directed energy deposition using a laser beam with wire (DED-LB/w). However, a significant challenge arises when DSS faces brittleness within the temperature range of 250–500 °C. This study employs advanced characterization techniques, including atom probe tomography (APT) and transmission electron microscopy (TEM), to investigate DSS embrittlement after aging at 400 °C for up to 1000 h. The hardness analysis revealed that the higher Ni content in DED-LB/w-fabricated DSS cylinder promotes the age hardening compared to 2205 wrought DSS plate. Furthermore, APT and TEM demonstrated that, alongside the decomposition of ferrite into Fe-rich (α) and Cr-rich (αʹ) phases, clustering of Ni, Mn, and Si atoms contributes to the embrittlement. Although the Ni-Mn-Si-rich clusters could suggest nucleation of G-phase, the G-phase crystal structure was not observed by TEM. This might be attributed to the short aging time or limitations in the characterization technique. This work underscores the impact of characterization techniques on the measurement of spinodal decomposition, with APT providing capability of detecting nanometer sized clusters. By elucidating the complexities of 475 °C-embrittlement in DED-LB/w DSS, this study offers valuable insights for industrial applications and a deeper understanding of age hardening in duplex DSSs under specific manufacturing conditions.

Effects of Low Nickel Content on Microstructure and High-Temperature Mechanical Properties of Al-7Si-1.5Cu-0.4Mg Aluminum Alloy

In this paper, the effects of Ni content on the room and elevated temperature (250 °C) tensile strength of Al-7Si-1.5Cu-0.4Mg-0.3Mn-0.1RE-xNi (x = 0, 0.3, 0.6, 0.9 wt.%) alloys were investigated, along with microstructure characterization and tensile testing. In the as-cast state, the dominant Ni-rich phases were primarily the γ-Al7Cu4Ni and δ-Al3CuNi phases. Following the solution heat treatment, a significant reduction in the γ-Al7Cu4Ni phase was noted, accompanied by the emergence of numerous small ε-Al3Ni phases. Both room temperature strength and high temperature strength at 250 °C exhibited a consistent increase with rising Ni content, reaching 405 MPa and 261 MPa, respectively, at 0.9 Ni content, which were increased by 6.4% and 16.8%, respectively, compared with 0 Ni content. The elongation exhibited an oscillating increase within the Ni content range of 0 to 0.6, reaching peak values of 2.6% in room temperature and 4.3% in high temperature at 0.6 Ni, followed by a rapid decline. At 0.6 Ni content, the alloy demonstrated a well-balanced combination of mechanical properties, featuring commendable strength and plasticity.

Effects of Ni Content and Heat Treatment on the Properties, Microstructures, and Precipitates of Cu-0.2 wt% Be-x wt% Ni Alloys.

Cu-Be alloys exhibit excellent comprehensive performance in electrics, thermotics, and mechanics, and hence, they attract much attention. Among them, low-Be copper alloys are more environmentally friendly and promising. This study explores the effects of different Ni contents and heat treatment parameters on the properties, microstructures, and precipitates of Cu-0.2 wt% Be-x wt% Ni (0 < x < 2.0) alloys. The experimental results demonstrate that the fast cooling rate of cast alloys during solidification contributes to retention of the solute atoms in the copper matrix, which is beneficial for subsequent solid solution treatment. Furthermore, solid solution treatment slightly reduces the electrical conductivities, microhardness values, and compressive yield strengths of Cu-0.2 wt% Be-1.0/1.6 wt% Ni alloys. The optimal solution temperature and time are about 925 ℃ and 60 min, respectively. Aging treatment significantly increases the electrical conductivities, microhardness values, and compressive yield strengths of Cu-0.2 wt% Be-1.0/1.6 wt% Ni alloys. The best aging temperature is around 450 ℃. However, the properties of Cu-0.2 wt%Be-0.4 wt%Ni alloys remain unaffected by solution and aging treatments. Around x = 1.0, Cu-0.2 wt% Be-x wt% Ni alloys possess the best comprehensive properties, which are about 72%IACS of electrical conductivity, 241 HV of microhardness, and 281MPa of compressive yield strength, respectively. TEM and EDS analyses reveal that the precipitate evolution of Cu-0.2 wt% Be-1.0 wt% Ni alloys with aging time is GP zones → γ″ → γ'. Notably, a distinct double-peak age strengthening phenomenon emerges with Cu-0.2 wt% Be-1.0/1.6 wt% Ni alloys. The precipitation of plenty of GP zones at the early stage of aging should account for the first strengthening peak, and the strengthening mechanism transformation of the γ″ or γ' phase from shear to Orowan should induce the second strengthening peak. This work may help to design new low-Be copper alloys and their preparation processes.

Effects of Ni content on microstructure and fracture toughness of the ZrN/TiNiN nano-multilayer films

ZrN and TiNiN nanolayers are alternately deposited on silicon substrate by magnetron sputtering. A series of ZrN/TiNiN nano-multilayer films with different Ni contents are prepared by varying the Ni:Ti volume ratio of the targets. The effects of Ni content on the microstructures and mechanical properties of ZrN/TiNiN nano-multilayer films are studied by X-ray diffractometer (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and nanoindentation instrument. The results show that with the increase of Ni content, the crystallization degree of ZrN phase first increases and then decreases. Besides, the hardness, elastic modulus and toughness of the films also increase first and then decrease with Ni content increasing. When Ni:Ti= 1:24, the ZrN/TiNiN nano-multilayer films obtain the highest hardness, elastic modulus and fracture toughness, which are 23.2 GPa, 317.8 GPa and 2.29 MPa·m1/2, respectively. This is mainly attributed to the best columnar crystal growth of the ZrN/TiNiN nano-multilayer film. The TiNiN layer changes into face centered cubic structure under the template of ZrN layer, and grows in coherent epitaxy with ZrN layer.

Adjustable damping properties of the AlCrFe2Nix medium entropy alloys by tuning phase constituent

The effects of Ni content on the phase constituent, mechanical properties and damping capacity of the AlCrFe2Nix (x = 1.0, 1.5, 1.7, 2.1, 2.2 and 2.3) medium entropy alloys (MEAs) were studied. When x = 2.1, the microstructure of the MEA consists of BCC phase as the matrix and FCC phase as the second phase with the corresponding volume fractions of 87.7, 12.3 vol%, respectively. The combination of hard BCC matrix and soft FCC secondary phase, especially, the BCC phase is isolated by the circular FCC phase, results in a very high damping capacity up to 0.06936 for the AlCrFe2Ni2.1 MEA at the corresponding strain amplitude of 2.55 × 10−4. Both the BCC matrix and the peculiar microstructure play a key role in increasing the damping capacity of the AlCrFe2Ni2.1 MEA. Excellent damping performance and comprehensive tensile properties of AlCrFe2Ni2.1 MEA indicate that it has potential applications as the candidate of damping materials.

Effect of Ni content on Cu–Mn/ZrO2 catalysts for methanol synthesis from CO2 hydrogenation

Cu–Mn/ZrO2 catalysts with different Ni contents were used for CO2 hydrogenation to methanol, among which the CMNZ-0.01 catalyst was the most effective, and the addition of Ni made the catalyst more oriented toward the COOH* pathway.

Effects of Ni content on microstructure and performance of MAO coatings on binary Al–Ni alloys

In this study, the pure Al and binary Al–Ni alloys with Ni addition of 1, 3, 6, and 10 wt % were coated via micro arc oxidation (MAO) in a tetraborate and phosphate based electrolyte for 60 min. With increased Ni content, the color of MAO coating became darker due to increased Ni-containing compounds on the surface. The Ni played a negative effect on the coating growth, decreasing both the coating thickness and surface roughness. The coatings on the Al–Ni alloys were mainly composed of γ-Al2O3 and α-Al2O3, and the Ni facilitated the formation of α-Al2O3 in the coating. Nanoparticles of NiO were generated around the edge of discharge channels for Al–6Ni and Al–10Ni alloys after a certain oxidation time. All coatings exhibited a uniform and dense surface structure, with the outer layer being more compact than the inner layer. Many tiny pores were found in the inner layer. Despite the corrosion resistance was decreased, the anti-wear performance of MAO treated samples was improved with the increased Ni content in the matrix. While, the corrosion resistance of the coated samples decreased with the adding of Ni content in the matrix.

Effect of Ni on microstructure and mechanical properties of Al-Cu-Mn alloy

The effects of Ni content on the microstructure and mechanical properties of Al-Cu-Mn alloys were systematically studied at both room temperature and high temperature. The results demonstrate that Ni effectively refines the grains. The primary Ni-containing phases in the 0.3% Ni alloy are Al3CuNi and Al7Cu4Ni phases. When the Ni content exceeds 0.3%, the dominant Ni-containing phase transforms into the Al7Cu4Ni phase. The increase in Ni content leads to the accumulation of Ni-containing intermetallic compounds at grain boundaries. Simultaneously, a significant amount of effective Cu concentration is consumed, reducing the presence of the strengthening Al2Cu phase in the alloy. Consequently, this causes a decrease in the alloy’s mechanical properties at room temperature. At a 0.3% Ni content, the alloy enriches the best high-temperature performance, revealing a tensile strength of 143 MPa at 300 °C and 94.8 MPa at 350 °C, which is 14.72% and 7 MPa higher than that of the base alloy. Due to the high thermal stability of the formed Ni-containing intermetallic compound, the grain boundary slip is effectively hindered under high-temperature conditions, thereby enhancing the high-temperature strength of the alloy. Additionally, the introduction of Ni at 300 °C effectively inhibits the growth of precipitate-free zones (PFZs). With increasing Ni content, the alloy undergoes the transition from ductile fracture to brittle fracture at room temperature. At 300 °C, the fracture evolution mode of the alloy gradually shifts from ductile fracture to ductile-transgranular mixed fracture and finally to transgranular fracture. At 350 °C, there is a gradual shift from the mixed intergranular-transgranular fracture mode to intergranular fracture.

Effect of Ni Content on the Microstructure, Performance, and Mechanical Properties of High-Entropy Alloy Nitride (AlCrTiMoVNi)N Coatings Produced by Cathodic Arc Evaporation

Effect of Ni Content on the Microstructure, Performance, and Mechanical Properties of High-Entropy Alloy Nitride (AlCrTiMoVNi)N Coatings Produced by Cathodic Arc Evaporation

Magnetic Properties of Fe–Mn–Ni Powders Prepared by Hydrogen Reduction of Wet-Synthesized Ferrite Nanopowders

Soft magnetic Fe- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</i> powders with different Ni compositions (Ni = 0, 2.2, 4.4, 6.7, and 8.8 at%) have been synthesized on a 1 kg batch scale, and the effect of Ni content on their magnetic properties has been investigated. The coercivity increased as the Ni content increased. The saturation magnetization was maximum for a Ni content of 4.4 at%. The magnetic properties of the Fe- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</i> powder synthesized in this study on a mass production scale achieved a coercivity of 0.77 Oe and a saturation magnetization of approximately 222 emu/g at a composition of 0.1 at% Mn and 2.2 at% Ni content.

Role of Ni content on microstructural and mechanical responses of Nb-stabilized metastable austenitic stainless steel weld metals

Three Nb-stabilized metastable austenitic stainless steel (15Cr–9Ni–Nb steel) weld metals with Ni contents of 8.4 wt%, 9.2 wt%, and 10.2 wt% were designed and prepared by gas tungsten arc welding. The effects of Ni content on the solidification behavior, microstructure, and the mechanism of deformation-induced martensitic transformation in the tensile process were investigated via scanning electron microscopy, transmission electron microscopy, scanning transmission electron microscopy, and high-resolution transmission electron microscopy, and their effects on mechanical properties were also discussed. As the Ni content increased, the solidification mode of weld metals changed from ferrite-austenite mode to austenite-ferrite mode, which made the segregation of Nb and Si at the interdendritic region more obvious and increased the total volume and the average size of primary NbC significantly. The large amount of coarse primary NbC in the AF weld metal damaged the impact toughness and reduction of area by inducing intergranular cracks and intergranular fractures. Moreover, both the three weld metals had poor mechanical stability and the deformation-induced martensitic transformation (DIMT) (γ→α′) occurred during the tensile process, which contributed to increased tensile strength. As the Ni content increased, the mechanical stability of austenite increased, and the strengthing effect of DIMT decreased, while the uniform elongation of weld metals increased.

Role of Ni Content on Microstructure, Mechanical Property, and In‐Site Local Corrosion Behavior of Welded Joints Produced by Laser Welding of Dual‐Phase Steel

Herein, the effects of Ni content on the microstructure, microhardness, and in‐site local corrosion behavior of laser‐welded joints in dual‐phase steel are investigated. The experimental results indicate that the microstructure of the fusion zone (FZ) changes from martensite to austenite as the Ni content increases. The FZ hardnesses of the 0Ni (no Ni foil addition) and 50Ni (50 μm Ni foil) welded joints are higher than that of the 100Ni (100 μm Ni foil) welded joints because of the austenite in the 100Ni welded joint. The welded joint without Ni shows severe pitting corrosion (more than 15 pitting sites in each zone of the welded joint) at the tested corrosion time. However, when immersed in the corrosion solution, the welded joints with added Ni exhibit slight pitting corrosion (less than five pitting sites). The Ni addition inhibits the pitting corrosion of the welded joints of high‐strength dual‐phase steel.

Effect of Ni content on the corrosion behavior of Mo2NiB2–Ni cermet in H2SO4 solution

To promote the utilization of Mo2NiB2–Ni cermet under sulfuric acid drew corrosion conditions, it is essential to elucidate the resistance mechanism of these cermets to sulfuric acid corrosion. In this study, the corrosion behavior of Mo2NiB2–Ni cermets with different Ni content in 90 wt % H2SO4 solution at 110 °C was investigated, and the corrosion resistance mechanism was analyzed. The results reveal that the corrosion weight losses and corrosion rates of the cermets decreased with increasing Ni content. Mo2NiB2–Ni cermets with higher Ni contents exhibited improved corrosion resistance. This improvement can be attributed to the generation of a considerable amount of NiSO4 corrosion products from the Ni binder phase corroded by H2SO4, which led to the subsequent formation of a large-scale, flat, and dense corrosion products layer with a certain thickness. This effectively prevented further erosion of the inner matrix and improved the corrosion resistance of the cermet. Additionally, the electrochemical results indicate that the corrosion product layer hindered the passage of electric charges through the layer, which inhibited the corrosion reaction.

Effects of Ni content and tempering temperatures on microstructure and properties of medium-carbon cast steel

Effects of Ni content and tempering temperatures on microstructure and properties of medium-carbon cast steel

Microstructure and low-temperature impact fracture behavior of QT400-18AL containing Ni

The effects of Ni content on the microstructures and low-temperature impact fracture behaviors of QT400-18AL ferritic ductile cast iron were systematically investigated by XRD, SEM, EBSD, and low-temperature impact test technique. The results demonstrate that the average diameter of graphite spheres and HAGBs increase with the increase of Ni content, whereas the nodule count, the crystal lattice constant and average grain size of the ferrite phase decrease. Additionally, the UTS, YS, and hardness of the QT400-18AL at room temperature increase with the increasing Ni content. The Ni-0.75 cast iron has the best room temperature mechanical properties with UTS of 391 MPa, YS of 253 MPa, and hardness of 140 HB. The average impact energy of the QT400-18AL decreases with the decrease in test temperatures and increase with the increase in Ni content at the same test temperatures. The fracture morphologies show that the ductile fracture zones increase with the increase in Ni content at the same impact temperature. Moreover, they decrease with the decreasing impact temperatures at the same Ni content, and the fracture types change from ductile fracture to ductile-brittle mixed fracture. The Ni-0.75 cast iron exerted satisfactory impact performance at −40 °C owing to the optimized combination of GBCD and dislocation density (KAM value), and its low-temperature impact energy was 12.64 J.

Enhancement of Elevated‐Temperature Strength in Al–Cu–Ce–Mn–Zr Cast Aluminum Alloy Through Ni Alloying

Herein, to enhance the elevated‐temperature strength of heat‐resistant aluminum alloys to satisfy application requirements, the effect of Ni content (0.5, 1.0, 2.0, 4.0 wt%) on the microstructures and tensile properties of Al–8.4Cu–2.3Ce–1.0Mn–0.2Zr alloy is investigated. The metallographic analysis techniques are used to quantitatively examine the microstructural changes. The skeleton‐like Al7Cu4Ni phase is formed after the addition of Ni and its morphology is gradually transformed into a coarse reticular‐like shape with Ni content increasing. However, the thermally stable Al8CeCu4 and Al24MnCu8Ce3 phases disappear when Ni content exceeds 1.0%. Al–8.4Cu–2.3Ce–1.0Mn–0.2Zr–0.5Ni alloy exhibits the optimal elevated‐temperature tensile performance at 400 °C, and its ultimate tensile strength, yield strength, and elongation at 400 °C reach 105, 85 MPa, and 16.5%, respectively. The optimal tensile performance is attributed to synergistic enhancing action of the thermostable Al8CeCu4, Al24MnCu8Ce3, Al16Cu4Mn2Ce, and Al7Cu4Ni phases at the grain boundaries and the nano‐sized Al20Cu2Mn3 and Al2Cu precipitates inside the grains. The typical brittle fracture is dominating in the five alloys with different Ni contents at ambient temperature, but the fracture mode at 400 °C is changed from ductile fracture to ductile and brittle mixed fracture with the increase of Ni.

Effect of Ni content on microstructure and mechanical properties for cold rolled 301L stainless steel

301L stainless steel (SS) ingots were prepared via aluminothermic reaction. In order to investigate effect of different content Ni addition on microstructure and mechanical properties of cold rolled 301L SS plate, real industrial process was simulated heat treatment and subsequent rolling process used. The results indicated that the tensile strength increased first and then decreased with the increasing of Ni content from 6.34% to 7.22%. The peak of tensile strength approximately reached 1275 MPa. The hardness remained basically unchanged at first and then decreased significantly to 305 HV. Fracture elongation tended to increase to 13.33%. It was found that when the Ni content reached 6.75%, the best mechanical property matching with strength of 1275 MPa and fracture elongation of 8.46% was obtained after rolling. The results provided experimental basis and theoretical support for the composition design of 301L SS for rail vehicles with both high strength and good plasticity.

Microstructure and mechanical properties of squeeze-cast Al-5.0Cu-1Mn-based alloys with different Ni content

In this study, the effects of Ni content on the microstructure and mechanical properties of Al-5.0Cu-1Mn-based alloys were investigated. The results demonstrate that Ni alloying refines the grain size and enhances castability. At low Ni content, some of Ni atoms participate in forming Al7Cu4Ni at the grain boundaries. The rest Ni segregates to the interface between α-Al and AlCu3Mn2 phase, which inhibits AlCu3Mn2 growth. The amount of Ni-rich phase at grain boundaries increases significantly as Ni concentration increases at the expense of the decline precipitates. After T6 treatment, the lamellar Ni-rich phase spheroidized into discrete particles that were uniformly distributed along the grain boundaries. Ni-rich phase of particles can effectively pin grain boundaries and prevent grain rotation. The optimum mechanical property is achieved with 1% Ni addition, predominantly due to the synergistic strengthening of eutectic strengthening and precipitation strengthening. The ultimate tensile strength, yield strength and elongation reach 505 MPa, 348 MPa and 16.5% respectively, which far exceed the current commercial cast aluminium alloys. With increasing Ni concentration, the fracture mode of the alloy changes from ductile fracture to brittle-ductile mixed fracture, because the high amount of Ni-rich phase intermetallic compounds increase the sites for localized brittle fractures.