Percentage Of Nickel Research Articles

Implementation of an innovative hybrid process based on electrodeionization for nickel and cobalt separation from synthetic pregnant leach solution

ABSTRACT In this study, an innovative hybrid process was proposed and examined as an alternative for nickel/cobalt separation from a synthetic pregnant leach solution. The first step was carried out by employing electrodeionization of a feed solution containing 950 ppm of nickel and 100 ppm of cobalt after adding EDTA to form (Ni-EDTA)−2 complex to suppress migration of nickel cations toward cathodic compartment. This process increased nickel percentage from 90.47 to 97 in the diluted feed solution. This solution was then subjected to cation exchanging process to adsorb the remaining cobalt cations, leading to a nickel purity of 99.7 wt% with an overall recovery 71.1%. On the other hand, the cathode rinse solution of EDI process which contained a major portion of the cobalt cations underwent three stages of extraction process using cyanex 272, resulting in recovery of 65.5 wt% of cobalt with a purity of 100%. It was seen that six stages of solvent extraction process were needed to reach the same purity of cobalt cations by the traditional extraction method. These findings highlight the superior performance of the proposed hybrid process, which not only yielded a relatively high recovery ratio but also ensured excellent purity of nickel and cobalt.

Preliminary Characterisation of Thermal Upgrading of Nickel from Saprolite via Selective Reduction

The mineralogical properties and distribution of information established in saprolite from Indonesia were investigated using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy energy dispersion spectroscopy (SEM–EDS) and differential thermal analysis (DTA) measurements. The findings suggest that laterite ore has a complex inner core. The percentages of nickel, iron, magnesium, aluminium and silicon in saprolite are 1.82 wt%, 30.47 wt%, 10–20 wt%, 4.86 wt% and 8.1 wt%. Saprolite has 53.1 wt% iron oxide/oxyhydroxide, 38.3 wt% lizardite and 8.7 wt% silicate. According to DTA, saprolite undergoes a phase shift from goethite to haematite at low temperatures (200–300°C). This is a suitable phase to optimise nickel diffusion in iron. Furthermore, the thermal upgrading approach was utilised for this saprolite.

SPECIATION OF HEAVY METALS AND MICROBIAL CONTAMINANTS IN HARMATTAN DUST WITHIN THE FEDERAL POLYTECHNIC KAURA NAMODA MAIN CAMPUS, ZAMFARA STATE

Harmattan dust is a natural phenomenon contributing to air pollution due to the presence of heavy metals and microorganisms. This research aimed to determine the speciation of heavy metal and microbial contaminants in Harmattan dust samples within the polytechnic Kaura Namoda. The composite sample of each month, namely, December 2023, January 2024, and February 2024, was collected with the aid of a sterilized petri dish. Five extraction phases were carried out, in order of mobility of the metals: exchangeable ion > metal bound with carbonate > metal bound to iron and manganese oxide > metals bound to organic matter and sulfide > residual phase. This was achieved using Tessie’s method and AAS for extraction and analysis. The result for the heavy metals shows Cr (13.6%) and Zn (25.5%) are more abundant in the exchangeable phases in December and January. Metals bound to Fe and MnO extraction phases have Zn (25.50%) abundance in December and January. The residual phase of extraction shows the highest percentage of pb (95.3%) and nickel (85.40%) for December and January. The bacteria and fungi identified are Bacillus cereus, Staphylococcus, Aspergillum, and Clodosporium, respectively. There is no significant difference in physicochemical parameters between the Harmattan dust samples collected in December, January, and February. The percentages of heavy metals in the Harmattan dust are high in the immobility phase of extraction, and bacterial and fungal levels are high in December and January. There is a need for preventive and protective measures to mitigate the health effects associated with...

Synthesis and characterization of magnetic nanoparticles decorated by carbon layers acting as defenders against bacterial infectious agents

High stability magnetic nanocomposites wrapped by carbon layers were efficiently synthesized using electrical arc powered by single arc unit. This is sufficient to ionize the nickel, and carbon electrodes immersed in distilled water through applying strong electric field between carbon rotatory cathode and nickel anode. Nickle decorated by carbon (Ni@C) nanocomposite was fully characterized by transmission electron microscope (TEM), X-ray Diffraction (XRD), Vibrating-sample magnetometer (VSM), UV/Visible Spectrophotometer (UV), Fourier-transform infrared spectroscopy (FTIR), Particle size analyzer (PZ), Zeta potential, and X-ray photoelectron spectroscopy (XPS). Ni particle was spherical with average size equals to 17 nm wrapped by carbon where its energy band gap values were 2.84 for C, and 3.36 eV for Ni. The estimated phase percentage of nickel was 64.8 % which is higher than the percentage of carbon layers that's donating the sample the observed high stability of zeta potential was found to be 26.4 mV. The saturation magnetization (Ms) and coercivity (Hc) examined were 10.624 emu/g and 80.648 G, respectively. The antibacterial effect of the synthesized nanocomposites was tested against standard ATCC (American Type Colony Collection) strains namely Pseudomonas aeruginosa 27853, Proteus mirabilis 35659, Proteus vurgalis 13315, Klebsiella pneumoniae 13883, and Staphylococcus epidermidis 12228. Proteus vurgalis 13315 was the most resistant strain which wasn't completely eradicated after 24 h incubation with the prepared nanoparticles. Further assessments through confocal microscope and reactive oxygen species (ROS) generation percentage were done to predict the possible antibacterial mechanism of the synthesized nanocomposite. Ultimately, the combined influence of nickel ions and carbon in the prepared Ni@C nanocomposite results in the suppression of bacterial respiration and the induction of oxidative stress, ultimately leading to bacterial cell death.

Waste to wealth: development of cladding flux from steel slag for submerged arc welding

A novel methodology has been developed which permits to transform waste slag into welding flux meant for stainless steel cladding. The developed flux has been applied for stainless steel cladding using submerged arc welding process. The claddings prepared using developed flux has been evaluated in terms of bead geometry, mechanical properties and chemical composition. The depth of penetration, weld bead width and height of reinforcement achieved with developed flux are 7.64 mm, 14.01 mm, and 4.07 mm, respectively, which are superior than obtained with fresh flux (8.05 mm, 12.85 mm, and 3.44 mm), as far as cladding is concerned. It observed that the developed flux is capable to produce chemical composition of claddings as per ASME SFA 5.4 standard. The percentage of chromium, nickel and manganese in claddings is 18.1%, 8.56% and 1.04% respectively which satisfy the ASME requirements. The side bend test proves a good bonding strength between substrate and claddings. The hardness of claddings produced with developed flux is also comparable with that of fresh flux. The average hardness of cladding produced with developed flux is 459 Hv, compared with that of fresh flux (435 Hv). The cost of developed flux is 54.86% economical than that of fresh flux. This research advocates that steel slag could be utilized as a raw material for manufacturing welding flux for stainless steel cladding.

Surface engineered sustainable nanocatalyst with improved coke resistance for dry methane reforming to produce hydrogen

The ever-growing carbon-based economy has led to alarming increases in greenhouse gas (GHG) emissions, particularly methane (CH4) and carbon dioxide (CO2). These emissions accelerate global warming, pollution and environmental challenges. Methane Dry Reforming (DRM) offers a promising technology to address this issue by converting CH4 and CO2 into a valuable syngas (CO + H2) mixture, which is a valuable fuel and a building block for many important chemical reactions (Fischer-Tropsch process). However, finding affordable and environmentally friendly catalysts for large-scale applications remains a critical hurdle. This study delves into the development of stable nickel-zirconia catalysts prepared via impregnation method. The weight percentage of nickel and zirconia was varied to optimize the catalyst's activity by controlling deactivation phenomenon that is a major challenge at higher temperatures during DRM. Various characterization techniques (XRD, FT-IR, SEM-EDX, TGA, TEM and BET) were employed to evaluate synthesized catalysts physio-chemical properties. Additionally, catalytic performance was assessed at temperatures ranging from 550 to 750 °C and a gas hourly space velocity (GHSV) of 72,000 mL/h.gcat. Among tested catalysts, 15% Ni/ZrO2 displayed remarkable conversion values for both CH4 (62.9%) and CO2 (64.9%). Importantly, it exhibited significantly lower weight loss (ca. 15.42%) compared to other variants, indicating better resilience against coke deposition. This enhanced stability can be attributed to synergistic interplay between nickel and zirconia support, effectively suppressing carbon formation. These findings demonstrate potential of 15% Ni/ZrO2 as a promising catalyst for experimental DRM application. With the obvious high activity and stability, 15% Ni/ZrO2 candidate serves as an eco-friendly candidate for greenhouse gas conversion into green fuel energy, contributing to a sustainable economy and clean environment.

Dyes Degradation Using Cooper-Nickel Ferrite and Its Tunable Structural and Photocatalytic Properties

Water pollution is a serious worldwide problem. Among its pollutants, dyes that are overused by various types of industries and are resistant to conventional effluent treatments stand out. In this study, mixed copper and nickel ferrites NixCu(1-x)Fe2O4 (x = 0, 0.2, 0.4, 0.6, 0.8 e 1.0), were produced by the EDTA-Citrate complexation method, characterized and applied in photocatalysis with methylene blue (MB) and rhodamine B (RhB) dyes, varying the reaction pH between 2, 6 and 10. The ferrites with the highest percentages of copper had a tetragonal structure, while those with the highest percentages of nickel had a cubic structure, all with inverse spinel and all presenting bandgap values lower than 2 eV. Samples with higher percentages of copper (x = 0 and 0.2) at pH 10 showed degradation of approximately 55% for RhB and 40% for MB. A mixture of MB and RhB was also evaluated, showing a greater removal of methylene blue due to its preferential adsorption on the surface of the material. In this way, mixed copper and nickel ferrites proved promising as catalysts in photocatalytic processes.

Microstructure investigation of light weight Al/Si/Ni hypoeutectic material prepared by powder metallurgy method

In this study, the researchers examined the impact of adding different percentages of nickel (0 %, 0.01 %, 0.05 %, 0.1 wt%) to an aluminum-silicon (Al-Si) alloy. Aluminum alloys are widely used in various industries due to their lightweight nature and favorable mechanical properties. The microstructure of the alloy was analyzed using X-ray diffraction (XRD) and scanning electron microscope (SEM) tests.The XRD and SEM analyses revealed that the Al-Si alloy consisted of two phases: α-Al and Si. The introduction of nickel resulted in the detection of an intermetallic compound (IMC) known as Al3Ni. This IMC caused changes in the lattice constant and interatomic spacing (dhkl). The observed distortions and densification in the microstructure were identified as indicators of increased hardness and strength in the alloys. The researchers attribute this enhancement in microstructure properties to the elevated temperature, which facilitated greater diffusion of nickel atoms into the aluminum lattice.

Investigation of ternary composites of polyaniline comprising benzalazine and nickel ions and its characterization

Recent research works are based on ternary polyaniline composite with nickel oxides, nickel ferrite, cobalt (II), copper (II) doped with graphene, manganese, PVA, carbon and more. Nickel itself being a magnetic material it is much suitable for super capacitive behaviour. Incorporating Nickel (II) chloride and Benzalazine in polyaniline composite will enhance its electromagnetic, electrochemical and mechanical properties. In the present work, ternary composites containing polyaniline, benzalazine and nickel (II) chloride were synthesized by the oxidative polymerization of aniline with different weight percentages of benzalazine and Nickel (II) chloride. Benzalazine gets physically adsorbed on the polymer chain and nickel ions get coordinated in the polymer chain. X-ray diffraction pattern was carried out to determine the crystalline nature of the synthesized samples. The synthesized polymer composites were subjected to the technique of Ultraviolet visible and Fourier transform infrared spectroscopic techniques to find out the optical properties. Surface morphology of the synthesized samples were analyzed using atomic force microscopy and Scanning electron microscopy. Redox behavior and capacitance studies were carried out by using cyclic voltammetry at different solution pH value and the synthesized composites at solution pH value pH 1.0 found to exhibit well defined capacitance behavior.

Influence of Nickel Percentage on Lattice Structure and Mechanical Strength in Al‐Si Alloy

Aluminum alloys play a crucial role in various industrial applications due to their low weight and favorable mechanical properties. The specific mechanical properties of aluminum alloys can be tailored through alloying and heat treatment processes to meet the requirements of different applications. This study focused on investigating the impact of Ni addition at different concentrations (0, 0.01, 0.05, and 0.1 wt. %) on the microstructure and mechanical strength of Al‐Si alloy. The evaluation was performed using X‐ray diffraction (XRD) and Vickers hardness (HV) tests. XRD analyses revealed that the Al‐Si alloy consisted of α‐Al and Si phases. Upon the addition of Ni, an intermetallic compound (IMC), Al3Ni, was identified. The presence of this IMC leads to changes in the lattice constant and interatomic spacing (dhkl). Vickers hardness (HV) measurements were performed on the samples before and after sintering. The results indicated that the highest hardness value obtained was 93 HV for the sample containing 0.1 wt.% Ni after sintering, whereas the lowest hardness value was 56 Hv for the sample without any nickel content before sintering. This increase in hardness can be attributed to the elevated temperature, which facilitated greater diffusion of nickel atoms into the aluminum lattice.

Spontaneous corrosion on the surface: Ni-regulated oxalates grown in situ on stainless steel for efficient oxygen evolution

Bimetallic NiFe-based materials are widely certified for their high performance in the oxygen evolution reaction (OER). In this work, a hydrothermal method was used to activate stainless steel (SS) with oxalic acid. The SS was used as the Fe source and carrier, and the in situ-grown NiFe oxalate microcrystals were synthesized by introducing a certain percentage of nickel to modulate the crystallographic appearance. In the crystal, the doped Ni couples with the surrounding Fe, prompting coordination defects in the lattice and generating more active vacancies. Meanwhile, the lattice deformation hinders the further stacking of the crystals, and the morphology of oxalates is regulated. This phenomenon is beneficial to optimize the intermediate adsorption step. In addition, the oxalate anions with strong complexation ability prevent the dissolution of the active substances during the catalytic process. Hence, NIO-SS electrode require only 315 mV and 391 mV of overpotential to achieve current densities of 50 and 100 mA·cm−2. At the same time, the stability of 100 h is maintained. This work presents a novel idea to improve the OER performance of stainless steel by spontaneous corrosion and Ni-regulated of the generated oxalates, promising to be used in actual production.

Influence of precursor compounds on the structural and catalytic properties of CoNiMo/SBA-15 catalysts used in the hydrodesulfurization of dibenzothiophene

In the present research project, it was studied in detail how the incorporation of different precursor compounds and the supplementary addition of amounts of nickel in the MoS2 slabs can influence the structural and catalytic properties of trimetallic CoNiMo catalysts supported on SBA-15 mesoporous support with precise control of the amount and nature of the promoters. The catalysts were prepared by the incipient impregnation method using ammonium heptamolybdate and cobalt and nickel acetate, and nitrate as precursors adding nickel in molar amounts (5, 10, and 20%) of the cobalt atomic loading. Adding the Ni in small amounts allows us to keep the (Co + Ni)/(Co+Ni+Mo) molar ratio near 0.3. The catalysts formed were labeled according to the precursor compounds used (CoNixMo-Ac for acetates and CoNixMo-N for nitrates), where x is the percentage of nickel. Catalysts were then characterized by N2 adsorption-desorption isotherms, X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Catalysts were tested in the HDS of dibenzothiophene (DBT).Results show a significant impact of adding small amounts of nickel and the type of precursor compounds used for the CoNiMo trimetallic catalysts on the final HDS activity. In the case of the catalysts prepared with cobalt and nickel acetates, it was observed that the initial reaction rate values increased as the amount of Ni increased, being the CoNi5Mo-Ac, the catalyst with the lower catalytic activity. Increasing the amount of Ni causes an increase in the HDS of DBT. In the case of the catalysts prepared with nitrates, it could be observed a similar effect. The catalyst with the higher catalytic activity in both series was the CoNi20Mo-Ac. These results agree with the TEM analysis in which a decrease in the slab length of the MoS2 could be regarded as the de Ni amount increase. This means that the type of precursor used has an essential effect on the catalysts since modify their properties and catalytic activity and suggests that the materials synthesized with acetate precursors can help to improve the intrinsic activity of the HDS sites.

Effects of Alloying Element and Heat Treatment on Mechanical Properties of Alloy Steels

The effects of Cr and Ni on three different types of steel with different carbon ratios under constant conditions such as the welding current 120A, voltage 80V, Diameter 10 mm and angle 60 degree was observed. Nickel percentage of up to 0.147% and Chromium 0.083% contributed to affecting the mechanical properties of the steel. Undissolved carbide particles refine the austenite grain size. In the presence of nickel, chromium carbide is less effective in austenite grain refinement than chromium carbide in absence of nickel at temperature below 975°C. Nickel does not produce any austenite grain refinement but presence of nickel promotes the formation of acicular ferrites. It was also found that Ni and Cr as chromium carbide also refines the ferrite grain size and morphology. Cr as chromium carbide is more effective in refining ferrite grain size than nickel. The microstructure of the base metal as a reference material was analysed before heating to support the results of chemical analysis. Nickel percentage of up to 0.147% and Chromium 0.083%. Molybdenum was 0.03% which contributed to affecting the mechanical properties of the steel.Keyword: Alloy steel, Heat treatment, Chromium, Nickel, Grain size

A Comparative study on Annealing and phase transition effect in SS 304 and SSLNA from low Nickel Austenite to Martensite

The critical investigation for the study of Stainless Steel (SS) properties modification by annealing process is carried out by three different phases. Generally Annealing of metals improves the straining element of that metal and makes it soften to elongation. The SS metals have been variedly used as utensils in the house wares. The drawability index for the SS has naturally evident with the mixture of alloying elements in it. Standard composition consists of considerable percentage of Nickel (Ni) in it say 8% in SS 304. The resource and availability of Ni in India is marginably reduces in recent years. To compensate the absence of Ni with 8% annealing process in different types of SS metals deployed including new standards SSLNA (Low Ni Austenitic grade of SS) in Steel Authority of India Limited. As discussed the three phases were, Coating of Metals during annealing, Morphological/structural modification using recrystallisation and Sample preparation technique for the softening process. This review entirely aims to improve the metallurgical characteristics of SS with low Ni composition.

Bio Removal of Heavy Metals from Soil and Plants Treated with Sludge

Sludge is one of the sources of organic fertilizer and it is rich in the necessary mineral elements, but global warnings confirm the presence of heavy elements that greatly hinder its use in agriculture, so this study was conducted as four levels of sludge were used (0,10,20,30) tons ha-1 and two types of the two bacteria, Enterobacter aerogenes, and Serratia marcescens, for the biological removal of heavy metals from the soil and reducing their uptake in plants. The results showed that the level is 30 tons ha-1 sludge gave the highest increase in the percentage of heavy metals in the plant and soil as it gave lead 4.81 ppm, cadmium 0.563 ppm and nickel 9.4 ppm in the plant. As for the soil, it gave lead 88.29 ppm, cadmium 2.134 ppm and nickel 78.8 ppm. The microorganisms had a positive effect in reducing the content of heavy elements in the plant, as the bacteria S. marcescens showed a significant effect in reducing the proportion of lead and cadmium, while the bacteria E. aerogenes had a significant effect in reducing the proportion of nickel. As for the soil, the bacteria S. marcescens and Enterobacter aerogenes had a significant effect in reducing the rate of lead, cadmium and nickel. The interaction also had a significant effect on reducing the content of heavy metals in the plant. The bacteria S. marcescens and E. aerogenes had a significant effect in reducing the percentage of lead when adding 30 tons ha-1 only. As for cadmium and nickel, S. marcescens and E. aerogenes achieved a significant response in reducing their content upon addition of 10, 20 and 30, respectively. As for the soil, the bacteria S. marcescens and E. aerogenes had a significant effect on reducing the percentage of lead when adding 20 and 30 tons ha-1 and S. marcescen bacteria also had a significant effect in reducing the percentage of nickel when adding 20 tons ha-1, while cadmium did not show any significant differences at any addition.

Performance of Electrocoagulation Process Using Iron and Aluminum Electrodes with and without Perforations

Electrocoagulation process is widely used for the removal of pollutants from the industrial wastewater. In the present study, an attempt was made to investigate the performance of electrocoagulation process using alu-minum and iron electrodes to treat the metal ions present in the synthetic galvanic wastewater. The electrodes used are with and without perforations and it was observed that the efficiency of electrodes with perforation (80 %) was higher than without perforations (50 %). The removal efficiency of heavy metal ions increased with retention time and direct current. The optimized values of residence time, voltage, pH, current, electrode spacing were 160 min, 6 V, 5, 0.2 A, and 3 cm, respectively. The maximum removal percentage of nickel and copper ions using perforated iron electrodes was 90.7 % and 86.0 %, respectively, and for chromium using a combination of perforated iron and aluminum electrodes it was 93.1 %. The removal of metal ions followed pseudo second order kinetic model with current dependent parameters.

Geological and Geochemical Investigation of Host Rocks of Ni-Cu in Suwar Area North Western Yemen

The Suwar Ni-Cu sulfide host rocks are located at the northwest of Yemen, about 18 km of Hajjah city. The host rocks at Suwar are associated with the ultramafic component of differentiated gabbroid intrusive.
 The results of chemical analysis of the major elements present in host rocks of Ni-Cu in Suwar area shows that, the magnesium oxide ranges from 20 to 30% , the silica oxide has an average 40% and iron oxids is also variegate between 14.4 and 18%.
 Based on the comparison between the results of the studied Ni-Cu sulfides in Suwar area with that obtained from famous international host rock, it is clear that there is a possible large collection of sulfides and Suwar host rocks which belong to the group which contains magnesium oxide (MgO) ranged between 15 and 33%, associated with high percentage of nickel and low percentage of copper. It also indicates similarity to Jinchuan and Kambalda magmatic bodies in China and Australia respectively. In addition, it shows that the nickel increases in ore with the increase of MgO contents in hosted rocks. Thus, there is a possibility of increasing percentage of nickel concentration in Suwar ore while the study is in progress. 

Perspective on ultrathin layered Ni-doped MoS2 hybrid nanostructures for the enhancement of electrochemical properties in supercapacitors

Over the last two decades, extensive study has been done on two-dimensional Molybdenum Sulphide (MoS2) due to its outstanding features in energy storage applications. Although MoS2 has a lot of active sulphur edges, the presence of inactive surfaces leads to limit conductivity and efficiency. Hence, in this article, we aimed to promote the additional active sites by doping various weight percentages (2%, 4%, 6%, 8% and 10%) of Nickel (Ni) into the MoS2 matrix by simple hydrothermal technique, and their doping effects were investigated with the help of Physio-chemical analyses. X-ray diffraction (XRD) pattern, Raman, and chemical composition (XPS) analyses were used to confirm the Ni incorporationin MoS2 nanosheets. Microscopic investigations demonstrated that Ni-doped MoS2 nanosheets were vertically aligned with enhanced interlayer spacing. Cyclic voltammetry, Galvanostatic charge–discharge, and electrochemical impedance spectroscopy investigations were used to characterize the electrochemical characteristics. The 6% Ni-doped MoS2 electrode material showed better CSP of 528.7 F/g @ 1 A/g and excellent electrochemical stability (85% of capacitance retention after 10,000 cycles at 5 A/g) compared to other electrode materials. Furthermore, the solid-state asymmetric supercapacitor was assembled using Ni-doped MoS2 and graphite as anode and cathode materials and analysed the electrochemical properties in the two-electrode system. To determine the impact of the Ni-atom on the MoS2 surface, first-principles computations were performed. Further, it was examined for electronic band structure, the projected density of states (PDOS) and Bader charge transfer analyses.

THE EFFECT OF ADDED NICKEL SLAG TO COMPRESSION AND SHEAR STRENGTH ON LATERITE SOIL SOUTH KALIMANTAN

Laterite soil is an embankment soil that is often used because it is easy to find and is widely found in South Kalimantan. However, this land has many shortcomings to be used as embankment soil. This is because the lateritic soil has a clay content and a high Plasticity Index (PI) value. So the quality is still questionable to be used as landfill. To overcome this, it is necessary to improve or stabilize the lateritic soil. In this study, the lateritic soil was stabilized by the addition of slag nickel This study aims to determine the physical characteristics of laterite soil after being given a mixture of nickel slag addition, this study also aims to determine the effect of the percentage of nickel slag on primary consolidation (Sc) of laterite soil. As well as knowing the effect of the percentage of nickel slag on the parameters of shear strength in the form of cohesion (c) and shear angle (f). Consolidation and shear strength specimens were made with 90% of the optimum moisture content. The variations of the nickel slag mixture used in this study were 0%, 5%, 10%, 15%, and 20% of the weight of the soil used. Based on the results of data analysis, the addition of a mixture of nickel slag in each sample variation can reduce the plasticity index value of the lateritic soil. In addition, the addition of nickel slag also affects the value of the primary consolidation settlement value (Sc) of the laterite soil. The addition of the percentage of nickel slag also affects the parameters of the shear strength of the soil, for the cohesion value (c) of the laterite soil experiences a value that decreases with the increase in the percentage of nickel slag. Meanwhile for the shear angle (φ) of the laterite soil, the value increases with the increase in the percentage of nickel slag.Keywords: laterite soil, nickel slag, plasticity index, consolidation of laterite soil, shear strength of laterite soil

Effects of Plasma Nitriding Process on AISI 304 Stainless Steel

AISI 304 stainless steel is a type of austenitic stainless steel that contains a high percentage of chromium and nickel. It is one of the most widely used grades of stainless steel and is commonly used in a variety of applications, including kitchen equipment, food processing equipment, and chemical processing equipment. AISI 304 stainless steel is a versatile and widely used material due to its excellent corrosion resistance, durability, and non-magnetic properties. Low-temperature processes like ion implantation, plasma nitriding can prevent the corrosion resistance of stainless steels by diffusion of plasma into the surface of the material, forming precipitation of Chromium nitride. For this research work, plasma nitriding is carried out on AISI 304 at low-temperatures 550°C for the time duration of 8 hrs, 16 hrs and 32 hrs. The formation of nitrogen-enriched layers with high nitrogen content promoted to increase in surface hardness. Wear test were carried out with pin on disc machine and the samples were undergone with hardness tests. The microstructures of plasma treated samples were compared with untreated microstructures. It was noted that phase change occurred from austenite to expanded austenite forming a hard layer from the surface level improving the wear resistance of the material.