Stainless Steel Metal Research Articles

Detection of Laterite Nickel Layer Distribution Based on Correlation of Multispectral Remote Sensing and Magnetic Satellite Data in North Konawe Region, Southeast Sulawesi

Abstract The demand for nickel continues to rise as an essential raw material to produce stainless steel and other metal alloys. Nickel deposits are abundant in Sulawesi Island due to their close association with tectonic plate movements. Therefore, this research aims to detect the distribution of laterite nickel based on the correlation of multispectral remote sensing and magnetic satellite methods in area X, North Konawe, Southeast Sulawesi. The remote sensing analysis utilized Landsat 8 with the combination of 6/5 band ratio to identify iron (Fe) and a 4/7 band ratio to detect quartz-bearing layers. Meanwhile, magnetic satellite data was obtained from The National Oceanic and Atmospheric Administration website with a total of 314 data. Based on the research results, there is a correlation between the two methods and geological mapping data where the iron (Fe) content in the limonite zone is dominant in the research area. The multispectral remote sensing analysis identified areas with high iron (Fe) content, which were further supported by magnetic satellite data showing magnetic anomalies from −0.312 to 0.178 nT. High anomalies within this range, particularly those between 0.004 and 0.178 nT, are indicative of layers rich in iron (Fe) within the limonite zone, thereby confirming the presence of laterite nickel deposits in the study area.

Characterization and Processing of Low-Grade Middle Group 2 Chromite Ore by Gravity Shaking Table and a Comparative SLon Magnetic Separation: A Case Study

Chromite is considered a strategic mineral in the global economy. It is mainly used as an essential raw material in the production of stainless steel and other metal alloys due to its corrosion and heat resistance properties. High-grade chromite resources are gradually depleting; with the increasing chromite demand in metallurgical applications, studies have focused on exploring low-grade and alternative chromite sources. This study proposes a cost-effective processing flowsheet for the low-grade middle group 2 (MG2) chromite layer, a poorly explored chromatite seam within the South African bushveld igneous complex (BIC). The study involved mineralogical characterization followed by gravity and magnetic separation of the low-grade MG2 ore at 18.18% Cr2O3. Characterization by XRD and Auto-SEM revealed that the ore mainly consists of pyroxene, chromite, and feldspar, with other minerals in trace quantities. The gravity separation test by shaking table upgraded the chromite (Cr2O3) to 42.0% at high chromite recoveries, whereas the laboratory Slon wet high-intensity magnetic separation method (SLon WHIMS) upgraded the chromite in the feed to 42.95% grade at lower chromite recoveries. Desliming the sample before the gravity and magnetic separation tests significantly improved the separation. The magnetic separation tests further demonstrated that chromite within the MG2 layer is sensitive to magnetic separation due to its high iron content. The adapted flowsheet is proposed as a cost-effective flowsheet for processing the low-grade MG2 layer. The flow sheet can be optimized by conducting the SLon WHIMS tests at high intensities followed by fine gravity tests by spiral circuits to maximize the chromite recovery while achieving commercial chromite grades and a Cr:Fe ratio greater than 1.5.

Design Modification and Finite Element Analysis of Stainless Steel 316L Locking Compression Plates for Mid-Transverse Fractures

Bone fracture is the most common orthopedics problem. To achieve stability in the internal fixation of bone fragments, apply a Locking Compression Plate (LCP), which consists of a set of plates and screws. Common materials used for the bone fixation plate are stainless steel, titanium, and other metal alloys. Those materials are stiffer than cortical bone, causing a stress shielding effect. The stress shielding phenomenon takes place during bone remodelling, which affects the growth of bone and bone loss upon the healing process. The purpose of this study is to design the best LCP to minimize or eliminate the stress shielding issue for tibia shaft fracture. A reverse engineering process is used to obtain the solid part using 3D scanning, and data clean-up is done in CATIA V5, which is then used to be imported into the finite element software ANSYS 23R2. The fracture simulation is on transverse type fractures with the creation of a gap of 1 mm around the mid-tibial shaft region. Several boundary conditions will be parametrized, such as material properties, contact definitions, meshing, and loading conditions in preprocessing. This paper examines and simulates the behaviour of LCP under a load via finite element analysis (FEA). Design 2 was selected due to its superior stress distribution,resulting in the LCP bearing only 177.98 MPa with a total deformation of 0.57 mm

Modern-Day Green Strategies for the Removal of Chromium from Wastewater.

Chromium is an essential element in various industrial processes, including stainless steel production, electroplating, metal finishing, leather tanning, photography, and textile manufacturing. However, it is also a well-documented contaminant of aquatic systems and agricultural land, posing significant economic and health challenges. The hexavalent form of chromium [Cr(VI)] is particularly toxic and carcinogenic, linked to severe health issues such as cancer, kidney disorders, liver failure, and environmental biomagnification. Due to the high risks associated with chromium contamination in potable water, researchers have focused on developing effective removal strategies. Among these strategies, biosorption has emerged as a promising, cost-effective, and energy-efficient method for eliminating toxic metals, especially chromium. This process utilizes agricultural waste, plants, algae, bacteria, fungi, and other biomass as adsorbents, demonstrating substantial potential for the remediation of heavy metals from contaminated environments at minimal cost. This review paper provides a comprehensive analysis of various strategies, materials, and mechanisms involved in the bioremediation of chromium, along with their commercial viability. It also highlights the advantages of biosorption over traditional chemical and physical methods, offering a thorough understanding of its applications and effectiveness.

Characterization of novel 3D-printed metal shielding for brachytherapy applicators.

To characterize 3D-printed stainless steel metal samples in the presence of an Iridium-192 source for organ-at-risk sparing in gynecologic brachytherapy. Samples of 3D-printed stainless steel (5.5×5.5 cm2, thickness range 1-5mm) were embedded in a solid water phantom at varying distances from source catheters. An Ir-192 brachytherapy source was passed through the phantom and the dose was measured using EBT3 Gafchromic film. The film was initially positioned in the sagittal plane 2cm away from the catheters, with the metal directly below and then 1cm from the film. A uniform dose was delivered at the film plane. A second setup measured a depth dose curve in solid water with film in the transverse plane directly above the metal samples. This setup was recreated using Monte Carlo simulations (EGSnrc egs_brachy). Validation between methods was performed with unshielded (solid water only) measurements. The planar dose passing through the metal samples (thickness 1-5mm) at the midpoint between the film and catheters, decreased compared to solid water by 7.4%±6.9% to 26.5%±5.5%. Dose enhancement on the order of 5% was noted when metal was directly adjacent to the film. The average decrease in depth dose from a single dwell position ranged from 10.0%±5.9% (1mm) to 21.1%±5.3% (5mm) as measured with film, and from 3.8%±0.9% (1mm) to 16.3%±0.9% (5mm) using MC simulation. The average depth dose values were measured using a line width of 2.5mm for film, and 3mm for MC simulation, and the measurements generally agree within standard error. The 3D-printed metal samples show potential for personalized applicators. Maximum dose reduction of 26.5%±5.5% compared to solid water was measured at 2cm from the source using the 5mm sample. An outer layer of solid water could potentially be used to reduce dose enhancement due to increased scatter near the metal.

Innovative pH-triggered antibacterial nanofibrous coatings for enhanced metallic implant properties

Metallic stainless steel bone implants are widely used due to their excellent mechanical properties, low cost, and ease of fabrication. Nanofibrous composite polymers have been proposed as coatings to promote biocompatibility and osseointegration, thanks to their biomimetic morphology that resembles the extracellular matrix. However, critical practical issues are often overlooked in the literature. For instance, applying coatings to implants with different shapes presents a significant technological challenge, as does evaluating viable sterilization procedures for hybrid devices containing electrospun polymers. In addition, infections pose a risk in any surgical procedure and can lead to implant failure, there is a need for antimicrobial prevention during surgery as well as in the short term afterward. In this work, we propose a new and straightforward method for manufacturing nanofibrous composite coatings directly on thin cylindrical-shaped metallic implants. Poly(ε-caprolactone) (PCL) nanofibers containing bioactive glass microparticles were electrospun onto stainless steel wires and then post-treated using two different strategies to achieve both hydrophilicity and surface disinfection. To address antimicrobial properties, amoxicillin-loaded Eudragit®E nanofibers were co-electrospun to impart pH-selective release behavior in event of a potential infection. The resulting composite hybrid coatings were characterized morphologically, physically, chemically, and electrochemically. The antibacterial behavior was evaluated at different media, confirming the release of the antibiotic in the pH range where infection is likely to occur. The impact of this study lies in its potential to significantly enhance the safety and efficacy of orthopedic implants by offering a novel, adaptable solution to combat infection. By integrating a pH-responsive drug delivery system with antimicrobial coatings, this approach not only provides a preventive measure during and after surgery but also addresses the growing issue of antibiotic resistance by targeting specific infection conditions.

EVALUATING THE MARGINAL DISCREPANCY AND SURFACE ROUGHNESS OF CAD - CAM MILLED VS 3D PRINTED PROVISIONAL CROWNS - AN INVITRO STUDY

Aims &Objectives: To evaluate Marginal discrepancy and Surface roughness of CAD-CAM Milled and 3D Printed provisional crowns after subjecting them to thermocycling. Materials and Methods: A stainless-steel metal die with ANSI/ADA specifications had been fabricated for the study. It was scanned with an intraoral scanner and the data was sent to VHF S5M CAD CAM milling and R3Pro printing machine. A total of 10 samples Milled Group A(n=10) and 10 Printed Group B(n=10) provisional crowns were fabricated from PMMA material using the scanned data. The temperatures for thermocycling are 37ºC and 60ºC. Each group is subdivided into two subgroups(n=5) based on thermocycling temperatures. The timeduration selected for Thermocycling was 7,14 and21 days. Marginal discrepancy was measured by using Stereomicroscope and Surface roughness was measured with Profilometer. Results: Marginal discrepancy values were greater in CAD CAM milled crowns(141.47 µm) than in Printed crowns(109.87 µm) at 60ºC after a time-period of 21days.Surface roughness values were higher in Milled crowns(3.915µm) than in CAD CAM Printed crowns(3.817µm) at 60ºC for a given time duration of 21days. One-way ANOVA statistical analysis was done. The mean marginal gap of CAD CAM Milled crowns was statistically significant than Printed crowns(p>0.05). Conclusion: Printed provisional restorationshad better Marginal accuracythan CAD CAM Milled provisional crowns. Surface roughness was higher in CAD CAM Milled crowns than in Printed provisional restorations.

Heavy metal in radiation therapy: A simple method to differentiate hip prosthesis materials.

In recent years, the number of hip replacement patients receiving radiation therapy has steadily increased. In parallel, strategies have been developed to reduce metal artifacts in computed tomography (CT) images and improve the accuracy of dose calculation algorithms. However, in certain situations, knowledge of the type of prosthesis material is required to accurately determine the dose distribution. This study aims to identify physical materials in hip prostheses to correctly assign them in the treatment planning system and improve dose calculation accuracy. We first verified the validity of the extended CT mass density calibration curve measured on titanium (Ti) and stainless steel (SS) metal inserts of two different diameters. Then using dedicated reference objects of various circular diameters, we developed a method based on interpolation functions to differentiate between Ti and SS material groups. Forty data sets from 18 patients were used to validate our method on two different reconstruction kernels: a standard Br44f and the electron DirectDensity (Sd40f) kernels from Siemens. Hounsfield units (HU) of Ti and SS inserts were found to vary widely depending on insert diameter, CT spectrum, and reconstruction kernels due to cupping artifacts. The largest HU difference (-79%) was obtained for SS at 70kV with Br44f when the diameter increased from 8 to 30mm. Therefore, under these conditions, the extended CT-density calibration curve is not recommended for heavy metal density determination. Using our interpolation-based method, we achieved excellent detection (100%) and material differentiation (100%) results for stems in both reconstruction kernels. At CT energies between 110 and 140kV, the detection and material differentiation rates were 93.3% and 92.9% for the heads and 93.3% and 92.9% for the acetabular cups, respectively, with the Br44f. Similarly, the use of Sd40f resulted in detection and differentiation rates of 94.7% and 100% for the heads and 100% and 95.0% for the acetabular cups, respectively. This method makes it possible to differentiate between hip prosthesis materials and correctly assign them to the Ti or SS group without prior knowledge of the prosthesis type, regardless of the reconstruction kernels. In combination with the Acuros XB (Varian) or Monte Carlo dose algorithms, excellent dosimetric accuracy can be achieved even in the vicinity of hip prostheses. By performing basic measurements, the method can be adapted to other CT units and reconstruction kernels, replacing the use of an extended CT-density calibration curve.

A Review on Metallurgical Issues in the Production and Welding Processes of Clad Steels.

Carbon and low-alloy steel plates clad with stainless steel or other metals are a good choice to meet the demand for cost-effective materials to be used in many corrosive environments. Numerous technical solutions are developed for the production of clad steel plates, as well as for their joining by fusion welding. For thick plates, a careful strategy is required in carrying out the multiple passes and in choosing the most suitable filler metals, having to take into account the composition of the base metal and the cladding layer. The specificity of the different processes and materials involved requires an adequate approach in the study of the metallurgical characteristics of clad steel, thus arousing the interest of researchers. Focusing mainly on ferritic steel plates clad with austenitic steel, this article aims to review the scientific literature of recent years which deals with both the production and the fusion welding processes. The metallurgical issues concerning the interfaces and the effects of microstructural characteristics on mechanical behaviour and corrosion resistance will be addressed; in particular, the effects on the fusion and thermally affected zones that form during the fusion welding and weld overlay processes will be analysed and discussed.

A Hermetic Package Technique for Multi-Functional Fiber Sensors through Pressure Boundary of Energy Systems Based on Glass Sealants

This paper presents a hermitic fiber sensor packaging technique that enables fiber sensors to be embedded in energy systems for performing multi-parameter measurements in high-temperature and strong radiation environments. A high-temperature, stable Intrinsic Fabry–Perot interferometer (IFPI) array, inscribed by a femtosecond laser direct writing scheme, is used to measure both temperature and pressure induced strain changes. To address the large disparity in thermo-expansion coefficients (TECs) between silica fibers and metal parts, glass sealants with TEC between silica optical fibers and metals were used to hermetically seal optical fiber sensors inside stainless steel metal tubes. The hermetically sealed package is validated for helium leakages between 1 MPa and 10 MPa using a helium leak detector. An IFPI sensor embedded in glass sealant was used to measure pressure. The paper demonstrates an effective technique to deploy fiber sensors to perform multi-parameter measurements in a wide range of energy systems that utilize high temperatures and strong radiation environments to achieve efficient energy production.

Electrospun Nano-Porous Cellulose Acetate Membrane Casted with Chitosan for Solid-State Sodium-Ion Batteries

Emerging as a safe and economically viable alternative to lithium-ion batteries, the solid-state sodium ion battery (ss-SIB) has captured increasing attention as a transformative technology for realizing a decarbonized economy and ensuring a sustainable energy supply. Here we report a nanoarchitecture strategy of biodegradable, biocompatible, and naturally abundant cellulose derivative (cellulose acetate, CA) and chitosan (CH) biopolymer-based nano-porous electrospun composite electrolyte (ECE) for flexible and wearable ss-SIBs. A simple combination of electrospinning and solution casting was utilized to fabricate mechanically robust (13.76 MPa), thin-film (0.067 mm), highly flexible, and high room temperature Na-ion conductive (1.04 x 10-4 S.cm-2) ECE. Lower activation energy (Ea = 0.13 eV) indicates easy charge carrier diffusion ability of as prepared ECE. The electrochemical stability window (ESW = 3.45 V) of ECE is studied by the linear sweep voltammetry (LSV) with respect to stainless steel and sodium metal electrodes. Uniform galvanostatic Na plating and stripping at room temperature is observed over 900 hrs at 0.5 mA•cm-2 current density in symmetric (Na|ECE|Na) cell performance, this underscores impressive electrochemical stability and compatibility with sodium metal. Using Na3V2(PO4)3 (NVP) as cathode, ECE, and Na metal as anode in the full cell, specific discharge capacity of 83 mA×h×g-1 at room temperature was attained at 0.1 C rate, highlighting the practical applicability of the nanostructured electrospun composite electrolyte for flexible and wearable ss-SIBs. Keywords Cellulose acetate, chitosan, electrospun, solid-state sodium-ion battery, specific discharge capacity.

Corrosion Evaluation of Metal Binder-Jetted Stainless Steel Parts: Influence of Printing Parameters on Performance

Additive manufacturing is a rapidly expanding fabrication process in both research and industry, capable of constructing parts layer by layer from a 3D CAD model. ASTM recognizes seven distinct additive manufacturing processes, with the majority capable of producing metal components. Among these technologies, binder jetting stands out, offering the potential to create a variety of metallic parts for applications in the biomedical and energy sectors at reduced costs and shorter lead times. Achieving acceptable corrosion resistance is crucial for such applications. Binder jetting exhibits advantages such as relatively high part density (~99%) and good surface roughness (~6μm for as-sintered parts), making it an ideal candidate for investigating corrosion behavior, given the general correlation between low surface roughness, high density, and improved corrosion performance. Despite its promise, binder jetting lacks standardized procedures for producing parts with specific properties, necessitating users to determine parameters through trial and error. The corrosion behavior of parts created through binder jetting remains uncertain due to various influencing parameters. This study focuses on two key printing factors: layer thickness and binder saturation, chosen due to their impact on surface roughness, density, and thereby on corrosion. Existing literature suggests that increased layer thickness may reduce powder bed density, potentially affecting green part density and causing more significant shrinkage during sintering. Simultaneously, binder saturation is recognized as a critical factor influencing final part quality. Predicting the combined impact of layer thickness and binder saturation on corrosion performance proves challenging. To unravel this relationship, we conducted experiments using an ExOne Innovate Plus metal binder jetting machine and 316L stainless steel metal powder (mean powder size of 22μm) which is widely recognized as the most common powder in research. A number of test runs were conducted by varying layer thickness and binder saturation, offering insights into their nuanced interplay in the context of corrosion performance. Initially, to address insufficient green strength, printer drying time and curing cycle time were optimized by conducting a series of experiments changing the drying time and curing time. Subsequent printing involved changing binder saturation parallel to the layer thickness variations, resulting in distinct parts with varying properties. Then the predetermined curing cycle was executed, followed by de-powdering, and sintering in a furnace. Sintering is imperative to increase the part density and enhance the overall strength of the final product. However, it's essential to acknowledge that sintering may adversely impact corrosion resistance due to the remaining porosity and surface fissures. The choice of sintering profile becomes crucial, necessitating careful consideration to minimize elemental migration during sintering and mitigate porosity. Scanning electron microscopy and optical microscopy are used to analyze sintered parts and interpret corrosion mechanisms. Electrochemical tests were conducted to identify corrosion rates, corrosion potential, passivation behavior, pitting potential, etc. in contrast with conventionally manufactured 316L in M NaCl solution. This study offers insights and recommendations aimed at enhancing the corrosion resistance of binder jetted stainless steel parts.

Beyond Traditional fuel cells: Development and a comprehensive analysis of mechanically Robust metal mesh-supported solid oxide fuel cell

At elevated operating temperatures, a large temperature gradient can cause irreparable damage to the solid oxide fuel cells (SOFCs) stack, eventually interrupting the durability of the stack. Metal substrate support could be used to overcome this challenge. However, the application of metal substrate support poses various challenges such as different thermal expansion coefficients, pore diameters, and complex fabrication techniques. Therefore, a first-ever novel and mechanically strong ferritic stainless-steel metal mesh-supported SOFC design is developed to mitigate these challenges. The metal mesh of 200 μm thickness is laminated with tape-casted green films of anode-support, anode functional layer (AFL), and electrolyte films of SOFC. The iso-static pressure of 300 MPa exhibits a firm attachment of the green films of SOFC with the metal mesh. Subsequently, the metal mesh-supported planar SOFC exhibits 3.3 times higher flexural strength compared to the conventional commercial anode-supported planar SOFC. The nano-CuO is added to constituent layers as a sintering aid to attain the maximum density at a lower sintering temperature of 1100 °C. The result shows that the practical application of the metal mesh-supported cell technology has a great potential to overwhelm the mechanical durability of SOFCs.

Composite scaffold of electrospun nano-porous cellulose acetate membrane casted with chitosan for flexible solid-state sodium-ion batteries

Emerging as a safe and economically viable alternative to lithium-ion batteries, the solid-state sodium ion battery (ss-SIB) has captured increasing attention as a transformative technology for realizing a decarbonized economy and ensuring a sustainable energy supply. Here we report a nanoarchitecture strategy of biodegradable, biocompatible, and naturally abundant cellulose derivative (cellulose acetate, CA) and chitosan (CH) biopolymer-based nano-porous electrospun composite electrolyte (ECE) for flexible and wearable ss-SIBs. A simple combination of electrospinning and solution casting was utilized to fabricate mechanically robust (13.76 MPa), thin-film (0.067 mm), and highly flexible ECE. The ionic conductivity of ECE was enhanced through optimization, taking into account the amount of sodium salt (NaPF6). The resulting ECE exhibited a sodium-ion conductivity of 1.04 ×10−4 S·cm−1 and a sodium ion transference number of 0.48 at room temperature (RT=23 °C). The obtained Na+ transference number of 0.48 and a low activation energy (Ea = 0.13 eV) indicate the easy charge carrier diffusion ability of as-prepared ECE. The electrochemical stability window (ESW = 4.04 V) of ECE is studied by the linear sweep voltammetry (LSV) with the assembly of stainless steel and sodium metal electrodes. Without any interfacial modification, a uniform, stable, and long-time room temperature (RT) galvanostatic Na plating-stripping was observed for 1000 hrs at 0.5 mA·cm−2 current density in a symmetric (Na|ECE|Na) cell, this underscores impressive electrochemical stability and compatibility of ECE with sodium metal. Utilizing Na3V2(PO4)3 (NVP) as cathode, fabricated ECE, and Na metal as anode in a hybrid full cell, a notable RT specific discharge capacity of 98.1 mA·h·g−1 was attained at a rate of 0.1 C with a capacity retention of 93.4 % over 120 charge-discharge cycles. This highlights the practical applicability of the nanostructured electrospun composite electrolyte for flexible and wearable ss-SIBs.

An in vitro comparative evaluation of cyclic fatigue resistance of two rotary and two reciprocating file systems.

Root canal instrumentation is one of the important procedures for successful endodontic therapy. Unexpected fracture of files occurs during root canal instrumentation without any visible signs of deformation compromising the success of root canal treatment. The aim of the study was to evaluate and compare cyclic fatigue resistance (CFR) of rotary and reciprocating files in simulated canals with 45°, 60°, and 90° angle of curvature. The study design was an In vitro study. Sixty nickel-titanium files, 30 each of rotary and reciprocating files were selected and divided into four groups (n = 15) of Neoendo Flex, ProTaper Next, WaveOne Gold (WOG), and Reciproc Blue (RPB) files. Each group was further subdivided into three subgroups containing five samples each based on their use in simulated canals with 45°, 60°, and 90° angle of curvature. To simulate root canals with 45°, 60°, and 90° angle of curvature, three artificial canals were designed in a stainless steel metal block. Each file was autoclaved, immersed in 3% sodium hypochlorite (NaOCl), and coated with 17% ethylenediaminetetraacetic acid (EDTA). Each file was tested for CFR using a torque-controlled reduction handpiece by instrumenting in a simulated canal for 10 s until fracture. The cycle of autoclaving, exposure to NaOCl, EDTA, and testing of CFR for 10 s per canal as per groups and subgroups was repeated again and again until the respective file fracture. The time taken to file fracture was recorded using a digital chronometer. The time taken for each file fracture (in minutes) was multiplied by the number of rotations per minute to attain the number of cycles to failure (NCF). The obtained results were subjected to statistical analysis using one-way analysis of variance and independent t-test. One-way ANOVA test showed a statistically significant difference between the four groups, P < 0.001. Independent "t"-test between individual subgroups showed a statistically significant difference, as P < 0.05. WOG and RPB reciprocating file systems showed superior CFR, more especially in canals with abrupt 90° angle of curvature compared to both rotary file systems tested. Among rotary file systems tested, Neoendo Flex showed greater CFR than ProTaper Next.

Metallic biomaterials in biopharmaceuticals and biomedical applications

Metallic biomaterials have captured a lot of interest because of their distinct mechanical characteristics, biocompatibility, and usefulness in biopharmaceutical and biomedical applications. These materials are essential for the creation of several medical equipment and treatment strategies. They include titanium, cobalt-chromium alloys, stainless steel, and biodegradable metals. Metallic implants in orthopaedics offer strong support for bone mending and joint replacement; they have outstanding load-bearing capacity and are resistant to corrosion and wear. Metallic heart valves and stents provide structural integrity and functionality in cardiovascular applications, enhancing patient outcomes in heart valve and coronary artery illness. Metallic biomaterials are manufactured systems created to give biological tissues intrinsic support, and they are commonly employed in stents, dental implants, orthopaedic fixations, and joint replacements. Increased implant-related issues are linked to higher biomaterial utilization because of weak implant integration, infections, mechanical instability, necrosis, and inflammation, as well as ensuring extended patient care, discomfort, and functional loss. The performance and integration of metallic biomaterials inside biological systems have been improved by developments in surface modification techniques, such as coating with biocompatible polymers and drug-eluting technology. Researchers are exploring the possibility of using biodegradable metals that eventually dissolve within the body reducing the risk of long-term issues and repeat procedures. Metallic nanoparticles have also demonstrated potential in increasing therapeutic efficacy, minimizing systemic adverse effects, and selectively targeting disease locations when included in drug delivery systems. The main metallic biomaterials will be briefly discussed in this review, along with the most important established and new methods for modification, which are used to enhance the durability, flexibility, biointegration, and of the biometals, and boost their suitability for 3D printing.

Failure analysis of stainless steel metal hose used for welding

While using ammonia (NH3) gas at 10 bar/500℃, a stainless steel 304 metal hose used as a bellow expansion joint was fractured. It was observed that the fracture of the metal hose started near the weld between the hose and the flange, and progressed to approximately 1/4 of the circumference of the weld.No metallurgical defects were found in the weld where the crack occurred. However, the folded part of the metal hose is welded to the flange, which can cause cracks. In other words, when the metal hose is forcibly compressed or stretched in order to weld it to the flange, the stress concentration due to cold work, including residual stress cause the metal hose to become brittle or crack. It is determined that when a high strain cyclic load or torsional deformation is applied to a high-hardness metal component, the metal hose will reach fatigue failure in a short period of time.

Utilization and Experimental Use of Stainless Steel Metal Scrap Machinery Waste, St-40 Iron, Copper and Aluminum to Reduce Co, Hc, Co2 Elements in Vehicle Exhaust

Air pollution due to motor vehicle exhaust emissions is increased. Polluted air harms human health dan the environment. Consequently, it is essential to make a sustained effort to reduce air pollution. The purpose of this research is to investigate the effect of adding aluminum scrap to the exhaust system of a motor vehicle on gas emissions composition. The motor vehicle exhaust system was modified to accommodate aluminum scrap placement. A gas analyzer was utilized to observe exhaust gas composition, such as carbon dioxide, hydrocarbon, and carbon monoxide. Aluminum scrap with different masses was wrapped around the exhaust's inner tube in 50 gr, 70 gr and 90 gr. The engine speed was maintained at 500 rpm throughout the testing process. It was found that the temperature of the outer exhaust tube is in a range of 40 degrees Celsius to 50 degrees Celsius. The results revealed that the most appropriate amount of aluminum scrap was 90 gr n to reduce carbon monoxide, hydrocarbon, and carbon dioxide in an exhausts gas. The surprising outcome was 76.78 % of carbon monoxide content declined, and furthermore hydrocarbon, and carbon dioxide content were deteriorated by 61.63% and 78.37%, respectively.

Results of Palliative Stenting in Malignant Superior Vena Cava Syndrome Analyzing Self-Expanding Stainless Steel and Nitinol Venous Bare Metal Stents.

The purpose was to analyze the technical, clinical, and survival outcomes of our patients with malignant superior cava vein syndrome (SVCS) treated with endovascular approach and analyze the efficacy of different stent types used. It is an observational, retrospective, single-center study. From 2006 to 2023, 42 patients (32 male, 10 female, mean age 62 years, age range, 41-87 years) underwent percutaneous stent placement for malignant SVCS. One stainless steel stent (Wallstent) and 2 venous nitinol stent type (Sinus-XL, Venovo) were used. Follow-up mean was 276 days. A total of 53 stents were deployed. Clinical success was 97.6% in less 24 hours. Technical success was achieved in 97.6%. No complications were found except 1 patient died during the procedure due to stent migration and atrial dissociation (2.3%). Overall intraprocedural stent migration rate was 11.9% (18.8% stainless steel stent, 9.6% nitinol stent, p>0.05). Overall survival rates were 87.8%, 41.99%, and 34.12%, and overall primary patency rates were 100%, 93.3%, 91.6% at 1, 6, and 12 months, respectively. Endovascular treatment is a safe and effective therapeutic option for SVCS with high technical and clinical success rates and low complication and recurrence rates. The malignant superior cava vein syndrome is a rare clinical entity treated classically with radiation and chemotherapy with a slower response, or surgical bypass, which is an aggressive surgical technique. Endovascular treatment offers a low-invasive technique with quick clinical resolution and good permeability results. However, further studies are lacking to deal with procedure technical characteristics, stent type used, technical complications, and medium- and long-term patency studies. This study aims to evaluate all these items, analysing self-expanding stainless steel and nitinol venous bare metal stents, and add value to endovascular treatment, confirming the good results of this technique.

Evaluation of the clinical application of personalized 3D printing and CAD/CAM resin crowns to replace stainless steel crowns in paediatric dentistry.

Children with dental caries are treated with stainless steel metal crowns (SSC), but the aesthetics and precision still need to be improved. Currently, both 3D-printed resin crowns (PRC) and computer-aided design/computer-aided manufacture (CAD/CAM) resin crowns (CRC) meet the clinical requirements for crown applications in terms of strength, production time, cost, and aesthetics. This study replaced SSC with customized resin crowns by 3D printing and CAD/CAM. In this study, PRC, CRC, and SSC were used for incisor and molar restorations, and 60 crowns were made with 10 for each group. The fabrication efficiency, surface characteristics, marginal fit, and stability of the two different crowns were evaluated. PRC and CRC show superior color and surface characteristics, though production times are longer (5.3-12.4 times and 3.3-9.1 times, respectively) than for SSC (p < .05). They, however, can be completed within 80 min. Edge gaps for PRC and CRC are significantly lower (13.0-19.2 times and 13.0-13.7 times) than for SSC (p < .05). All materials exhibit good stability. The 3D-PRCs and CAD/CAM resin crowns may replace SSCs as a potential choice for clinical child caries.