Nickel-chromium Alloy Research Articles

Ultrasound-assisted rapid growth of chemically bonded bifunctional mesoporous covalent organic framework submicrospheres on a nickel-chromium alloy support for efficient solid-phase microextraction of bisphenols from water and milk samples

A layer-by-layer chemical bonding strategy was developed for fast in situ growth of bifunctional mesoporous covalent organic framework submicrospheres (COF SMSs) on the nickel-chromium alloy (Ni-Cr) fiber substrate via the ultrasound-assisted Schiff-base reaction for the first time. COF SMSs showed well-defined morphology, extraordinary high surface area (1211 m2·g−1) and narrow mesopore (2.50 nm) as well as excellent stability. Furthermore, the resulting Ni-Cr fiber presented outstanding adsorption capability and improved selectivity for bisphenols (BPs). Consequently, an attractive SPME-HPLC-UV approach with the Ni-Cr@Ni-Cr LDHs NSs@COF SMSs fiber was proposed for rapid preconcentration and sensitive determination of BPs. By optimizing adsorption parameters, the SPME-HPLC-UV method presented good linearity for five BPs in the ranges of 0.02–200 ng·mL−1 with coefficients of determination (R2) higher than 0.999. Limits of detection and limits of quantitation were obtained from 0.003 ng·mL−1 to 0.006 ng·mL−1 and from 0.010 to 0.019 ng·mL−1, respectively. Moreover, the intra-day and inter-day precision expressed as relative standard deviations (RSDs) was 1.57–3.52 % and 2.65–4.38 % for the proposed method with a single fiber, respectively. RSDs of the proposed method with different duplicate fibers were 3.25–6.72 %. The proposed SPME-HPLC-UV method was available for efficient preconcentration and sensitive detection of five BPs from real water and milk samples. The relative recoveries at three spiking levels of BPs were achieved in the range of 80.00–118.8 % with RSDs below 7.81 %. In addition, the prepared fiber still exhibited satisfactory adsorption performance after 120 adsorption-desorption cycles.

Experimental study on the plate-type fuel melting behavior based on alternative materials

In this paper, low-temperature experiments are carried out on the visualized experimental device to study the melting behavior of plate-type fuel in severe accidents of the reactor. In the experiments, the plate-type fuel with different sizes made of nickel–chromium alloy, zinc and aluminum was used to carry out the visualized experiments in air, argon, and vacuum environment. It was found that both the size of the plate and the experimental environment have a significant influence on the melting behavior in this study. And the temperature distribution, melting behavior characteristic, the key parameters such as blistering position, blistering size, breaking position and breaking size were also obtained. Based on the experimental data, the physical phenomena and processes related to the blistering and melting of the fuel plates are analyzed in this paper, which provides experimental data support for the development of analysis model and formulating perfect mitigation strategies for severe accidents.

Creation of Tool Coatings Based on Titanium Diboride for Highly Efficient Milling of Chromium–Nickel Alloys

Creation of Tool Coatings Based on Titanium Diboride for Highly Efficient Milling of Chromium–Nickel Alloys

Crack characteristics of pulsed laser brazed diamond grinding wheel

Experiments on pulsed laser brazing of diamond grinding wheels were carried out in this paper. The crack characteristics and residual stress of brazed layer were detected and evaluated. The influence laws of pulse width, frequency, diamond mixing ratio, number of stacked layers, powder thickness and preheating temperature on crack characteristics were investigated. The pulsed laser characteristic coefficients (peak pulse power density/pulse interval time) and the correlation law between thermal stresses and cracks are discussed. The results show that the pulse width and frequency of the pulsed laser affect the cracking rate by varying the energy input and the time between pulses. The existence of a suitable value for the pulse characteristic coefficient corresponding to pulse width and frequency corresponds to a lower cracking rate. Thermal stress variations due to changes in process conditions at different diamond percentages, number of stacked layers, and preheating temperatures are the main causes of crack rate variations. Cracking is not only affected by thermal stresses, but also by the quality of the formed surface when pulsed laser brazing diamond to nickel–chromium alloy brazing material. For example, the main reason for the variation in cracking rate is the change in the morphology of the molded surface due to the variation in the thickness of the powder spread at different variations in the thickness of the powder spread.

The impact of various substrates, ceramic shades, and brands on the ultimate color and masking capacity of highly translucent monolithic zirconia: an in vitro study.

This study aimed to examine the impact of substrates, ceramic shades, and brands on the color and masking ability of highly translucent monolithic zirconia (HTMZ) using CIELab and CIEΔE2000 metrics. A total of 156 1-mm thick HTMZ disks in shades A1, A2, and A3 were produced using Dental Direkt and Kerox zirconia brands. Four 3-mm thick substrates (nickel-chromium alloy, non-precious gold alloy (NPG), zirconia shade A2, and resin composite shade A2) were prepared. HTMZ disks were overlaid on these substrates, and color measurements were taken with a spectrophotometer. Color differences (ΔE) were analyzed using CIELab and CIEΔE2000 formulas. The influence of brand, shade, substrate, and their interactions on ΔE values was assessed with a General Linear Model (GLM) and LSD pairwise comparison test. Spearman's correlation test examined the relationship between CIELab and CIEΔE2000 values. Results indicated that ΔEab was significantly influenced by substrate type and shade, while ΔE2000 was also affected by the ceramic brand. Mean color differences across ceramic-substrate groups were within clinically acceptable and perceptible ranges (clinically perceptible: ∆Eab ≥ 1.3 and ∆E2000 ≥ 0.8; clinically acceptable: 0.8 < ∆E2000 ≤ 1.8 and 1.3 < ∆Eab ≤ 2.7), except for NPG, which had ΔE values exceeding the perceptible range (ΔE2000: 1.1 ± 0.11 to 1.8 ± 0.31; ΔEab: 1.61 ± 0.15 to 2.16 ± 0.36). A significant correlation (r = 0.974, P < 0.001) was found between ΔEab and ΔE2000. Various ceramic brands and shades led to notable ΔE variations, yet average color differences within all ceramic-substrate groups remained clinically acceptable. Both ΔEab and ΔE2000 were reliable methods with a strong correlation for measuring color differences.

Research on the Structural–Phase and Physical–Mechanical Characteristics of the Cr3C2-NiCr Composite Coating Deposited by the HVOF Method on E110 Zirconium Alloy

Composite coatings based on chromium carbide (Cr3C2) and nickel–chromium alloys (NiCr) are widely used due to their unique properties, including high heat resistance, wear resistance and corrosion resistance. This article studies the structural–phase and physical–mechanical characteristics of Cr3C2-NiCr composite coatings applied by high-velocity oxygen fuel to E110 zirconium alloy. The HVOF method was chosen to create coatings with high adhesion to the substrate and excellent performance properties. Analysis of the microstructure of the cross-section showed the thickness of the modified surface layer from 75 to 110 μm, depending on the processing modes. Energy dispersive X-ray spectral analysis revealed the presence of elements Cr, Ni, C and O in the coating composition. Structural–phase analysis confirmed the formation of coatings with a high concentration of Cr3C2 carbide particles and NiCr (nickel–chromium) phases. The resulting composite coatings based on Cr3C2-NiCr had a significantly high microhardness, ranging from HV 1190 to HV 1280, and the friction coefficient varied in a significant range from 0.679 to 0.502 depending on the processing conditions. The maximum adhesion strength was 9.19 MPa per square centimeter.

Development of Nickel-Chromium Alloy Electroplating and Its Surface Morphology Studies for Automobile Industries

In the electroplating industry, alloy plating is typically one of the most difficult processes. We are showcasing the Ni-Cr (Nickel Chromium) alloy electroplating in our work. Trivalent chromium bath is made in order to resist the hazardous hexavalent chromium, and co-deposition of chromium and nickel is accomplished. Our work is appropriate for industrial electroplating in the automotive industry because Ni-Cr alloy exhibits good corrosion resistance along with features including wear resistance, ductility, and thermal stability. Through the use of SEM (Scanning Electron Microscopy), EDAX (Energy Dispersive X-Ray Analysis), and XRD (X-Ray Diffraction) studies, we are able to clearly observe the surface morphology in this project. These research allow us to observe the Porous behavior surfaces. Figure 1

Design and Manufacturing of Air Conditioning Coil

This paper consists of the detail design process of a cooling coil which is used in Evaporator of VARC System for given cooling load. The process consists of designing a part using the calculation and various other parameters. The stability of long-term materials is becoming increasingly important as the demand for air conditioning systems in commercial and residential applications grows. Because of temperature variations and heat flow, materials in air conditioning systems can fail, reducing the cooling effect of the system. Low thermal transitions through the coil's material cause a significant amount of heat to be wasted in the evaporator coil, which lowers the system's overall efficiency. This paper outlines the methodology used to choose the right material for the evaporator coil in an air conditioning system using the CES Granta design software. Based on design and functional requirements, nickel-chromium alloys, pure titanium, copper, low alloy steel, cast iron, and pure titanium are the candidates that made the shortlist for evaporator coils. The best candidates are low alloy steel, titanium, and stainless steel.

Study on seawater corrosion resistance of copper alloy

Abstract The Marine environment is a very complex and corrosive environment. Marine corrosion environment can be generally divided into Marine atmospheric environment and seawater environment. Because the seawater is rich in a variety of free ions mixed with corrosive media, the main component is sodium chloride, in addition to containing magnesium, potassium, iodine, bromine, and other elements of salt, which has strong corrosion to metal materials, if serious, it will cause safety accidents. Therefore, ensuring the effectiveness of the anticorrosion system is very important for the safe and reliable operation of the offshore platform. pulse plating is used and the metal nickel coating and metal nickel-chromium coating are prepared to analyze the microstructure and corrosion resistance of each film layer. From the macroscopic, it can be found that three coatings have more or less corrosion phenomenon, there is obviously no nickel-chromium and nickel layer on the surface of nickel-chromium corrosion defects, and through scanning electron microscopic observation, microscopic level nickel chromium corrosion after corrosion phenomenon is the least of three layers, which suggests that nickel chromium seawater corrosion resistance is strong. The three layers are then electrochemical corroded to study the corrosion resistance of the three layers. The results show that the corrosion resistance of the nickel-plated layer, nickel-chromium coating, and nickel-iron chromium coating prepared in the copper substrate is improved successively, which shows the influence of different membrane elements on the corrosion resistance of copper substrate against seawater medium. Although the composition parameters of the various membrane layers vary, they experience the same corrosion mechanism-pitting; Nickel chromium and chromium, iron and other atoms are present in the nickel matrix in the form of solid solution and finally form the solid solution alloy coating. For nickel-chromium coating, the content of iron and chromium in the surface layer has a certain influence on the corrosion resistance of the metal coating. The electrochemical parameters of nickel plating are studied separately, and the comparison with the nickel-chromium alloy coating and the coating is conducted. The equivalent circuit is fitted and determines the largest impedance value and the largest phase Angle among the three membrane layers, which finally has the strongest seawater corrosion resistance.

A Technique for In-Situ Displacement and Strain Measurement with Laboratory-Scale X-Ray Computed Tomography

Abstract Purpose: Establish a technique for simultaneous interrupted volumetric imaging of internal structure and time-resolved full-field surface strain measurements during in-situ X-ray micro-computed tomography (XCT) experiments. This enables in-situ testing of stiff materials with large forces relative to the compliance of the in-situ load frame, which might exhibit localization (e.g., necking, compaction banding) and other inhomogeneous behaviors.Methods: The system utilizes a combination of in-situ XCT, 2D X-ray imaging, and particle tracking to conduct volumetric imaging of the internal structure of a specimen with interrupted loading and surface strain mapping during loading. Critically, prior to the laboratory-scale XCT experiments, specimens are speckled with a high-X-ray-contrast powder that is bonded the surface. During in-situ loading, the XCT system is programmed to capture sequential 2D X-ray images orthogonal to the speckled specimen surface. A single particle tracking (SPT) or digital image correlation (DIC) algorithm is used to measure full-field surface strain evolution throughout the time-sequence of images. At specified crosshead displacements, the motion and 2D image sequence is paused for volumetric XCT image collection. Results: We show example results on a micro-tensile demonstration specimen additive manufactured from Inconel 718 nickel-chrome alloy. Results include XCT volume reconstructions, crosshead-based engineering stress, and full-field strain maps. Conclusion: We demonstrate an in-situ technique to obtain surface strain evolution during laboratory-scale XCT testing and interrupted volumetric imaging. This allows closer investigation of, for example, the effect of micro-pores on the strain localization behavior of additive manufactured metal alloys. In addition to describing the method using a representative test piece, the dataset and code are published as open-source resources for the community. Graphical abstract

Advancing the Frontiers of Neuroelectrodes: A Paradigm Shift towards Enhanced Biocompatibility and Electrochemical Performance.

The aim of this study is the fabrication of unprecedented neuroelectrodes, replete with exceptional biological and electrical attributes. Commencing with the synthesis of polyethylene glycol and polyethyleneimine-modified iron oxide nanoparticles, the grafting of Dimyristoyl phosphatidylcholine was embarked upon to generate DMPC-SPION nanoparticles. Subsequently, the deposition of DMPC-SPIONs onto a nickel-chromium alloy electrode facilitated the inception of an innovative neuroelectrode-DMPC-SPION. A meticulous characterization of DMPC-SPIONs ensued, encompassing zeta potential, infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction analyses. Evaluations pertaining to hemolysis and cytotoxicity were conducted to ascertain the biocompatibility and biosafety of DMPC-SPIONs. Ultimately, a comprehensive assessment of the biocompatibility, electrochemical properties, and electrophysiological signal acquisition capabilities of DMPC-SPION neuroelectrodes was undertaken. These findings conclusively affirm the exemplary biocompatibility, electrochemical capabilities, and outstanding capability in recording electrical signals of DMPC-SPION neuroelectrodes, with an astounding 91.4% augmentation in electrode charge and a noteworthy 13% decline in impedance, with peak potentials reaching as high as 171 μV and an impressive signal-to-noise ratio of 15.92. Intriguingly, the novel DMPC-SPION neuroelectrodes herald an innovative pathway towards injury repair as well as the diagnosis and treatment of neurological disorders.

Characteristics of Si (C,N) Silicon Carbonitride Layers on the Surface of Ni-Cr Alloys Used in Dental Prosthetics.

Chromium- and cobalt-based alloys, as well as chrome-nickel steels, are most used in dental prosthetics. Unfortunately, these alloys, especially nickel-based alloys, can cause allergic reactions. A disadvantage of these alloys is also insufficient corrosion resistance. To improve the properties of these alloys, amorphous Si (C,N) coatings were deposited on the surfaces of metal specimens. This paper characterizes coatings of silicon carbide nitrides, deposited by the magnetron sputtering method on the surface of nickel-chromium alloys used in dental prosthetics. Depending on the deposition parameters, coatings with varying carbon to nitrogen ratios were obtained. The study analyzed their structure and chemical and phase composition. In addition, a study of surface wettability and surface roughness was performed. Based on the results obtained, it was found that amorphous coatings of Si (C,N) type with thicknesses of 2 to 4.5 µm were obtained. All obtained coatings increase the value of surface free energy. The study showed that Si (C,N)-type films can be used in dental prosthetics as protective coatings.

Design, fabrication and experimental verification of a drag sail based on thermal-driven controllable bi-stable shape memory polymer composite booms

Deployable drag sails are used for passively deorbiting defunct satellites and other spacecraft. Designing the deployable boom is the main challenge in this technology. We present a bi-stable shape memory polymer composite (Bi-SMPC) boom with high stiffness, a high unfolding/folding ratio, and consistent roll-out deployment. It was designed and fabricated by a strategy of controlling the gradual release of elastic energy stored in a bi-stable composite structure through thermal-driven SMP matrix. Two heating layer strategies were investigated experimentally to determine the optimal driving layer and driving parameters. Based on these parameters, verification tests of a four-stage deployment Bi-SMPC boom were conducted. Meanwhile, a proof-of-concept prototype of a four-stage deployment drag sail based on the Bi-SMPC booms was designed and fabricated. Tests were conducted to verify the effectiveness of the drag sail deployed by the booms. It was found that SMPs can effectively control the deployment of bistable composite structures. The nickel-chromium alloy heating layer offers a more uniform driving temperature field compared to carbon fiber. The drag sail can be deployed successfully under the driving of four Bi-SMPC booms.

Excitation functions of the α-particle-induced reactions on natCr up to 50 MeV

Activation cross sections of the α-particle-induced reactions on natCr were measured. A stacked foil activation technique and γ-ray spectrometry were used. Nickel-chromium alloy, nickel and titanium metallic foils were stacked as a target. The target was irradiated with a 51.2-MeV α-particle beam at the AVF cyclotron, RIKEN. The γ rays were measured for the irradiated foils using an HPGe detector. Production cross sections of 52gFe, 52g,54Mn, 48,51Cr and 48V radionuclides were determined. The cross sections determined in this experiment were compared with the literature data and found to be consistent with them.

Analysis of subgingival microbiota and IL-1β, TNF-α and CX3CL1 levels in gingival crevicular fluid of fixed dental prostheses.

Prosthetic biomaterials can affect the composition of the subgingival microbiota and consequently the production of proinflammatory cytokines, causing damage to the periodontium. A total of 40 patients were divided into two groups: 20 with monolithic zirconia (MZ) prostheses and 20 with porcelain fused to metal (PFM) with nickel-chromium (Ni-Cr) alloy prostheses. Subgingival plaque and gingival crevicular fluid samples were taken. The Checkerboard technique for DNA-DNA hybridization and the enzyme-linked immunosorbent assay technique were performed. Teeth with MZ presented a lower percentage of bleeding on probing and tooth mobility compared to teeth with PFM with Ni-Cr alloy. Prosthodontic teeth harbored higher total levels of the 18 bacterial species than non-prosthodontic teeth. There was a higher prevalence of S. gordonii and V. parvula species in PFM with Ni-Cr alloy compared to MZ. There was an increase in IL-1β, TNF-α and CX3CL1 levels in PFM with Ni-Cr alloy compared to MZ. MZ is a candidate biomaterial with fewer negative effects on the periodontium, allowing for longer prostheses longevity in the mouth.

The Impact of Recasting on the Bond Strength of Metal Ceramic Restorations

Objective The objective of this study is to evaluate the effect of recasting of Nickel Chromium (Ni-Cr) alloy on the bond strength of metal-ceramic restoration. Materials and Methods Forty-five samples fabricated from one Ni-Cr alloy were divided into three groups. Group 1 consisted of 100% fresh alloy; Group 2 consisted of 50% fresh alloy mixed with 50% alloy taken from sprue and button remnants of group 1 and group 3 consisted of 50% new alloy mixed with 50% alloy taken from sprue and button remnants of group 2. All samples were then bonded to a ceramic material. The bond strength of the Metal-Ceramic was then assessed using a 3-point bending test. The failure mode was investigated under a stereomicroscope and confirmed under scanning electron microscopy (SEM). Results Group 1 (100% fresh alloy) showed the highest bond strength amongst the other groups, while the lowest was recorded for group 3 (50% fresh alloy with 50% cast twice alloy). According to the International Organization for Standardization (ISO), the bond strength of fresh alloy and the group casted once attained the required level. Conclusion The outcome of this study indicates that the use of 100% fresh Ni-Cr base metal alloy yields the highest bond strength of metal ceramic restoration.

A Lab-Based Study to Assess the Surface Roughness of Various Investments: An Original Research.

Surface roughness of the crowns is dependent on the pattern material used for the making as well as the procedure of investing. The study was aimed to examine the impact of various pattern materials and investment procedures on the surface roughness of nickel-chromium alloy raw castings. An in-vitro study was piloted at a tertiary care hospital. Eighty samples of inlay wax and pattern resin were divided equally. They were invested in phosphate-bonded investment material and kept under normal atmospheric pressure as well as invested under a pressure of 3 bars. The surface roughness was calculated with a Profilometer. The values obtained were compared using statistical tools keeping P < 0.05 as significant. Lowest surface roughness was seen for the wax pattern invested under positive pressure. While the highest was seen for the resin patterns invested at room pressure. A significant variance between the wax 1 and wax 2 (P < 0.01); as well as between the wax 2 vs. Resin 2 specimens (P < 0.01) was noted. Wax patterns can be suggested as the material and method of choice because they showed the least amount of surface roughness when placed under pressure. Resin patterns when invested under pressure can also be suggested as an alternate as they also exhibited similar surface roughness as that of the wax.

Design and synthesis of a nickel–chromium alloy catalyst for hydrogen generation from hydrazine monohydrate

A combined theoretical and experimental study found that nickel–chromium alloying could significantly improve the activity and selectivity towards hydrogen generation from hydrazine monohydrate.

ANALYSIS OF THERMODYNAMIC, STRESS-STRAIN, AND LOADED STATES OF CHROMIUM-NICKEL ALLOY WORKPIECES USING MACHINING PROCESS SIMULATION IN ADVANTAGE SOFTWARE

Machining difficult-to-cut materials, which include most high-alloy chromium-nickel steels and alloys, requires optimization of cutting parameters, correct application of tool materials, cutting blade geometry, etc. The particular relevance of a scientifically based analysis in addressing these issues is due to the large costs incurred in machining products made from such materials. The possibilities of experimental research to provide correct technological recommendations are quite limited. Instead, analytical modeling is imperfect due to the complexity of formalizing dynamic processes accompanied by fast-moving power, thermodynamic, and stress-strain phenomena. An effective research mechanism is simulation modeling of the cutting process of a hard-to-machine material (including in the AdvantEdge software). The article presents an analysis of the results of simulation studies of the influence of the main parameters of machining (depth and cutting speed) on the formation of power, thermodynamic, and stress-strain (including residual) parameters formed during cutting of chromium-nickel alloy Inconel IN 718. This analysis allows us to conclude the feasibility of choosing cutting parameters to ensure the effective performance properties of products made of this material

Characteristics of dental materials in the oral cavities of Asian individuals between their 20s and early 40s living temporarily in Japan based on 38 case studies.

Characterization of materials used in dental restorations and fixed prostheses is useful for personal identification. This study investigated the dental treatment trends and use of metal materials among non-Japanese Asian temporary residents and Japanese individuals aged from 20 to 40 years living in a city in Japan. Analysis of 38 participants from different Asian countries showed prominent use of resin fillings, with metal element analysis revealing nickel-chromium (Ni-Cr) or cobalt-chromium (Co-Cr) alloys. Among five Japanese participants of the same age with dental metal treatment scars, resin fillings and silver-palladium-copper-gold (Ag-Pd-Cu-Au) or silver-indium (Ag-In) alloys were observed. This study suggested some regional differences in dental material choices in Asia.