Effect Of Nickel Addition Research Articles

Effect of Nickel Addition on Solidification Microstructure and Tensile Properties of Cast 7075 Aluminum Alloy

In order to explore the casting technology of a high–strength aluminum alloy, the effects of nickel on the solidified microstructure and tensile properties of a 7075 aluminum alloy were studied. 7075 aluminum alloys without nickel and with 0.6% and 1.2% nickel were prepared by a casting method. The results showed that the increase of Ni content in the 7075 alloys increased the liquidus temperatures, primary α (Al) grains were refined significantly, and the divorced eutectic structure was gradually formed among α (Al) grains with the preformation of the Al3Ni phase. In comparison, the 7075 alloy with 0.6% nickel content had less intergranular shrinkage porosity, and its elongation and ultimate tensile strength was enhanced 45% and 105% higher than those of the as-cast 7075 aluminum alloy, respectively. When the Ni content was increased to 1.2%, the eutectic phases of the alloy became much coarser compared to the other two alloys, and the mechanical properties obviously reduced too.

Plasma electrolytic oxidation of as-cast and heat-treated binary Al-Ni alloys

In this study, the effect of nickel addition on the plasma electrolytic oxidation (PEO) behavior of pure Al was investigated. Binary Al-Ni alloys containing 1, 3, 5 and 7 at. % Ni were produced by two step vacuum arc and induction melting methods. Produced alloys and pure Al as a reference were PEO coated in a silicate-based alkaline electrolyte through a bipolar power source under constant voltage mode for 45 min. The samples were characterized by XRD, SEM-EDS and Vickers microhardness tester before and after PEO. All alloys were consisted of Al and Al3Ni phases. Fine rod-like eutectic structure was evident for 1 (hypoeutectic) and 3 (eutectic) at. % Ni containing alloys while further addition of Ni resulted in the coarsening of eutectic Al3Ni precipitates. All coatings contained γ-Al2O3 phase while additionally, α-Al2O3 phase formed on pure Al and Al-1Ni alloy. Despite the presence of Ni in the coatings, a Ni-based oxide phase was not evident. Ni, as an alloying element, is found to decrease microhardness and thickness of the coatings, induced a thickness variation between the regions close to the edge and center of the samples. This edge effect was maximum on eutectic alloy, which consisted of homogeneously distributed fine Al3Ni precipitates. To investigate the relationship between eutectic precipitate size and the edge effect, Al-3Ni alloy was heat-treated at 620 °C for 168 h and subsequently coated by PEO. Heat-treatment almost eliminated the edge effect, increased the average coating thickness and promoted the α-Al2O3 formation. Fine eutectic morphology in Al-Ni alloys is found to be detrimental for the coatings produced by PEO.

Effect of nickel addition on the physicochemical properties of SrTiO3-based materials

Synthesis of materials in Ni/SrTiO 3 system was undertaken. Perovskite structure material with nominal composition SrTi 0.98 O 3 was synthesised by the sol-gel method. Nickel was introduced into the system by the wet impregnation method followed by proper thermal treatment. Two research paths were carried out: the evaluation of sintering conditions on material properties (sintering temperature: 1100, 1200, 1300 and 1400 °C; sintering time: 1, 3 and 5 h for sintering at 1300 °C) and the effect of nickel addition on the material properties - 1, 2, and 5 mol% of Ni compared to the amount of Ti was introduced into the analysed system. The microstructures of the materials, together with their structural (XRD analysis) and electrical (total conductivity and Seebeck coefficient) properties, were determined. Furthermore, temperature-programmed reduction (TPR) and temperature-programmed oxidation (TPOx) measurements were performed to evaluate the materials’ redox properties. It was shown that less than 1 mol% of Ni could be incorporated into the strontium titanate structure when a wet impregnation was chosen as the method for the introduction of Ni into the SrTiO 3 -based system. NiO and, for the highest amount of introduced nickel, also NiTiO 3 were the main additional nickel-containing phases. For all materials synthesised in the Ni/SrTiO 3 system, the positive value of the Seebeck coefficient was observed, suggesting that nickel is an acceptor-type dopant while incorporated into the perovskite structure. However, the TPR measurements clearly imply that nickel can be incorporated into the strontium titanate structure in various oxidation states.

Experimental investigation and validation on the effect of nickel addition on properties of the pressureless sintered boron carbide composites using machine learning models

This research work aims to investigate the effect of a low amount of nickel (<0.6 wt%) on the properties of the boron carbide. The samples are synthesized through pressureless sintering at 2150 °C under an argon atmosphere (1 bar). Firstly, the thermodynamic simulation is carried out using the HSC software to determine the free energy change of reactions and their viability. The prepared samples are analyzed by employing various characterization techniques such as XRD, FESEM, and EDS. It is concluded that the presence of nickel (i.e., a low melting point than the boron carbide) results in the formation of the liquid phase during the sintering process. Thus, the sinterability of the samples is significantly enhanced. Moreover, the optimum sample is obtained by adding the 4 wt% of nickel in boron carbide. The maximum density, hardness, elastic modulus, and fracture toughness for the sample containing 4 wt% nickel are obtained as 91.00%, 21.83 GPa, 374.45 GPa, and 3.11 MPa m0.5, respectively. Furthermore, machine learning (ML) techniques (i.e., M5P tree model, random tree, REPTree (Reduced-Error Pruning), and artificial neural network (ANN)) are also utilized to check the adequacy of the results. It is concluded that the maximum value of CC, i.e., 0.9929, is obtained for the REPTree technique with a minimum value of MAE (i.e., 0.0869) and RMSE (i.e., 0.0968). It is observed that the ML technique showed the validation of experimental results.

Effect of nickel addition on enhancing nano-structuring and suppressing TRIP effect in Fe40Mn40Co10Cr10 high entropy alloy during high-pressure torsion

The present work unravels the effect of nickel (Ni) addition on the deformation mechanism and hardness evolution in a Fe40Mn40Co10Cr10 high entropy alloy (HEA) during high-pressure torsion (HPT) processing. For this purpose, two variants of the high entropy Cantor alloy, with compositions (atomic%) Fe40Mn40Co10Cr10 (Ni0 alloy) and Fe35Mn35Co10Cr10Ni10 (Ni10 alloy) were selected. The study revealed a transition in the predominant plasticity mechanism with addition of Ni from TRIP in Ni0 to dislocation slip in Ni10 alloy. Such transition of plasticity mechanism was the direct consequence of an increase in the free energy of phase transformation, ΔGγ→ε towards a more positive value with Ni addition. Interestingly, the Ni10 alloy showed a greater extent of nano-structuring than the Ni0 alloy with nearly three-fold refined grain sizes, that is, lesser than 30 nm in Ni10 alloy and ∼90 nm in Ni0 alloy. Furthermore, a 3–4 times higher dislocation density was observed in the FCC phase of the Ni10 alloy compared to that in the transformed HCP phase in the Ni0 alloy for any given HPT processing conditions. These differences in mechanism(s) of deformation and the extent of nano-structuring manifested as a greater ability of Ni added Ni10 alloy to harden itself during HPT. The present study suggests that a large fraction of hard HCP phase originating from TRIP effect in the Ni0 alloy has a lower hardening ability than the high dislocation density and nano-structuring in the Ni10 alloy.

Effect of Nickel Addition on the Microstructure and Toughness of Shielded Metal Arc Welded SS400 Steel

Nickel alloying element has been known to play a role in controlling the formation of microstructures in the weld metal (WM). This experiment aims to study the relationship between nickel addition to the microstructure evolution and toughness of shielded metal arc welded SS400 low carbon steel plates. Three welded samples, Ni-01, Ni-03 and Ni-09 were fabricated using electrodes containing different nickel: &lt;0.1% Ni, 0.3% Ni, and 0.95% Ni, respectively. Microstructure of WM was examined using an optical microscope and scanning electron microscopy, and mechanical properties were measured in strength and toughness. The results showed the impact toughness increased when the nickel content of electrodes increased. From the three experimental welded samples, WM of Ni-09 which using electrodes containing 0.95% Ni demonstrated the best result for the impact toughness. It may caused Ni-09 has more AF and finer grains size compared to Ni-01 and Ni-03. It seems with nickel addition in the WM, finer grain size and acicular ferrite (AF) formation were developed.

The catalytic activity of microporous and mesoporous NiCoBeta zeolite catalysts in Fischer–Tropsch synthesis

Two kinds of microporous and mesoporous NiCoBeta zeolite catalysts were prepared. The effect of bimetallic zeolite preparation method, dealumination degree, the presence of micropores in the support structure and the effect of nickel addition on the activity and selectivity of cobalt-based microporous and mesoporous dealuminated and non-dealuminated zeolite catalysts in Fischer–Tropsch synthesis were determined. These catalysts were obtained by sequential impregnation (Ni3.0Co20AlBeta and Ni3.0Co20SiBeta) and co-impregnation (co-Ni3.0Co20AlBeta and co-Ni3.0Co20SiBeta). The study showed that the presence of Ni leads to a lower cobalt oxide reduction temperature and an increase in CO conversion. Nickel–cobalt zeolite systems showed high activity and selectivity throughout the lifetime of the reaction. The use of a two-step post-synthesis method and the promotion of cobalt systems with nickel allow to obtain active, selective, and stable zeolite catalysts for Fischer–Tropsch synthesis.

Effect of nickel addition on microstructure, tensile and corrosion properties of cold rolled silicon bronze

In this study, silicon bronze (Cu-Si) with nickel addition was fabricated using double stir casting technique. The influence of nickel addition and cold deformation on the microstructure, hardness, tensile and corrosion properties of the fabricated alloys were investigated. The microstructure of the alloy was evaluated using an optical microscope. Microhardness tester was used to determine the hardness while the tensile property was obtained from the hardness data. Potentiodynamic polarization measurement was used to study corrosion behaviour in 0.5 M H2SO4. The result show that the Ni modified Cu-Si alloys revealed the presence of Cu rich α-phase and δ-Ni2Si precipitates along the α grain boundaries. The δ-Ni2Si precipitates increased with increase in Ni content. The addition of Ni reduces the grain sizes and refine the microstructure. The hardness and tensile strength of the Ni modified Cu-Si increased with an increase in Ni addition from 0.2 to 0.8 wt%. The silicon bronze showed excellent corrosion resistance in a sulfuric acid environment with Ni addition. This is evident from the reduction in corrosion current density (Icorr) with an increase in Ni content.

Effect of microstructural phases on thermo-mechanical analysis of ductile Cu–Al–Mn–Ni memory alloys for structural applications

In this present study, the particulars of an experimental investigation on the effect of nickel addition on microstructural, strain recovery and strain absorption capacity of ternary (Cu–Al–Mn) shape memory alloys has been deliberated. Six dissimilar compositions with varying amounts of Ni in (Cu–Al–Mn) shape memory alloys have been synthesized and investigated to measure their potential for structural applications. Microstructural and detailed phase analysis has been studied. Additions of Ni have enhanced the tensile strength of these alloys. These compositional variations have influenced shape memory and damping properties in from of dissipated strain energy as well as the super elasticity of the alloys.

Effect of Nickel Addition on the Corrosion Resistance of Steel in a Subtropical Seashore Environment

Effect of Nickel Addition on the Corrosion Resistance of Steel in a Subtropical Seashore Environment

Effect of Nickel Alloying and Mechanical Stirring on the Microstructure and Mechanical Properties of Al – 10% Si – 5% Cu Alloy

The effect of nickel additions on the microstructure and ultimate tensile strength of alloy Al – 10% Si – 5% Cu in cast and heat treated conditions is studied. The nickel content optimum for obtaining a maximum-strength alloy is determined. The conditions at which a fishbone morphology negatively affecting the mechanical properties does not form are determined. Mechanical stirring of the melt before crystallization is shown to affect positively the strength and the structure of the alloy.

Effect of nickel addition on densification, microstructure and wear behaviour of spark plasma sintered CP-titanium

Titanium alloys with varying amounts of nickel additions (2, 6 and 10 wt%) were prepared through the spark plasma sintering technique. The influence of nickel additions on densification, microstructure and wear behaviour of the sintered alloys was investigated, against commercially-pure titanium (CP–Ti). SEM analysis results showed a mixed portion of dark background (α-Ti), white patches and bright spots within the matrix of the sintered binary alloys compared to sintered CP-Ti matrix. These white patches and bright spots were confirmed by the X-ray diffraction (XRD) results to be a mixture of intermetallic phases of Ti2Ni (FCC) and TiNi2 (HCP). The relative density and the microhardness value were found to increase from 91.42% to 99.6% and 212 HV0.1 to 343 HV0.1 respectively. Estimated yield and tensile strength values were observed to vary linearly with increasing concentration of Ni in the sintered alloys. Analysis of the worn surfaces indicated improved resistance to adhesive and abrasive wear with increasing nickel content in the sintered alloys.

Effect of Nickel Addition on the Magnetic and Microstructural Properties of Cu-Al-Fe Alloy

The Ni addition on the magnetic properties of a Cu-10%Al-5%Fe (wt.%) alloy was studied. The alloy was produced by an arc melting method, and its magnetic properties such as coercivity and magnetization saturation were measured using a physical property measuring system (PPMS) instrument. In addition, structural properties of the alloys were characterized by the use of X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. From SEM observations, two distinct phases were found to be in the microstructure consisting of (α + γ2) eutectoid and kappa (κI, κII, and κIII) phases. After the addition of the Ni element in the Cu-10%Al-5%Fe, we observed a decrement for the secondary κII phase. The magnetization curves, M-H, exhibited a clear ferromagnetic behavior. Present results indicate soft magnetic properties for the investigated alloy.

Effect of nickel additions on microstructure evolution and mechanical properties of low-alloy Cr-Mo cast steel

This paper presents investigation of nickel additions on the low-alloy Cr-Mo cast steel which was normalized at temperature of 920 °C. In this experiment, approximately 0.3, 0.5, and 1.0 wt% Ni was added into the Fe-1.0Mn-0.8Cr-0.4Mo cast steel. The microstructure of low-alloy Cr-Mo cast steel was observed by optical microscope and scanning electron microscope, and the phase compositions were identified by EDX analysis. Tensile, hardness, and Charpy impact tests were conducted to investigate correlation between nickel additions to microstructure characteristics and mechanical properties. The results show that increasing nickel from 0.3 to 1.0 wt% on the alloys has improved the strength without sacrificing the impact toughness. Ni addition into low alloy steel increased the austenite stability due to the grain refinement. The strength was found increase linearly with Ni addition which may caused mainly by solid solution strengthening due to Ni dissolved into the ferrite matrix.

A new intermetallic phase formation in Mg[sbnd]Si[sbnd]Ni magnesium-based in-situ formed alloys

The effects of nickel addition on the microstructure and phase formation in the magnesium-silicon alloy were studied. Besides the primary and eutectic in-situ formed Mg2Si phase in the MgSi alloys, a new intermetallic phase was identified in the Ni-containing alloys. Based on energy-dispersive spectroscopy (EDS) and X-ray diffraction analyses, it was shown that this phase contains Mg, Ni, and Si elements, which contradicts the presence of the expected Mg2Ni phase. Through rigorous EDS analysis, the new in-situ formed phase was identified as (Mg,Ni)3Si or more accurately as Mg8Ni7Si5 intermetallic compound, called χ-phase, which has not been reported so far in the MgSiNi ternary space. Finally, the properties of the studied MgSiNi alloys were also briefly discussed.

Effect of Nickel Addition on Sintering Behavior and Electrical Conductivity of BaCe0.35Zr0.5Y0.15O3-δ

Effect of Nickel Addition on Sintering Behavior and Electrical Conductivity of BaCe0.35Zr0.5Y0.15O3-δ

Effect of Nickel Addition on Microstructure and Mechanical Properties of the Spark Plasma Sintered Ti–6Al–4V Alloy

The effect of nickel addition (2–6 wt%) to Ti–6Al–4V has been investigated using spark plasma sintering. The sintered samples were studied and characterized by using field emission scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy and X-ray diffraction techniques. Mechanical properties of the sintered samples were determined. Results show that an increase in nickel addition significantly reduces the relative densities from 97.9 to 95.9% and the microhardness of the alloys increases from 330 to 502 HV500. The microstructural studies reveal a transformation; as Ni content increases, the equiaxed alpha phase and Widmanstatten alpha platelets in the Ti–6Al–4V alloy get refined and develop the clear grain boundaries with Widmanstatten lamellar microstructure. Sintered samples held for 30 min has the highest hardness value, while fracture morphology of the sintered compacts shows a transgranular fracture with fine dimple’s features, confirming good strength and cohesion of the grains. The percentage of elongation is greatly affected by the addition of nickel so that the sample exhibits a brittle nature with high ultimate tensile strength.

Effect of nickel addition on the microstructure and corrosion resistance properties of porous alumina composites shaped with sugarcane bagasse pore-forming agent

In this study, the effect of nickel (Ni) addition on the microstructure and corrosion resistance properties of porous alumina (Al2O3) composites shaped with sugarcane bagasse pore-forming agent were evaluated. Plain and Ni-reinforced porous alumina sampels (Al2O3-xNi-RH; x = 2, 4, 6 and 8wt%) were prepared using the powder metallurgy method. Experimental results showed that the porosity (50.4-57.1vol%) and the pore size (62-109µm) of the porous alumina composites increased with rising content of Ni reinforcement. The XRD results showed that the Al2O3 matrix and Ni reinforcement reacted during the heat treatment process to produce nickel aluminate (NiAl2O4) spinel. Corrosion resistance results showed that the porous alumina composites exhibited better chemical stability in strong alkali solution as compared with strong acid solution.

Effects of nickel addition during different phases of solid waste decomposition

Effects of nickel addition during different phases of solid waste decomposition

Effect of nickel addition on mechanical properties of powder forged Fe-Cu-C

Fe-Cu-C system is very popular in P/M industry for its good compressibility and dimensional stability with high strength. Fe-Cu-C is a structural material and is used where high strength with high hardness is required. The composition of powder metallurgy steel plays a vital role in the microstructure and physical properties of the sintered component. Fe-2Cu-0.7C-Ni alloy with varying nickel composition (0%, 0.5%, 1.0%, 1.5%, 2.0%, and 3.0%) wt. % was prepared by powder metallurgy (P/M) sinter forging process. The present work discuss the effect of varying nickel content on microstructure and mechanical properties.