Cobalt Alloy Research Articles

Comparing the performance of a femoral shaft fracture fixation using implants with biodegradable and non-biodegradable materials.

Abstract Orthopedic injuries, such as femur shaft fractures, often require surgical intervention to promote healing and functional recovery. Metal plate implants are widely used due to their mechanical strength and biocompatibility. Biodegradable metal plate implants, including those made from magnesium, zinc, and iron alloys, offer distinct advantages over non-biodegradable materials like stainless steel, titanium, and cobalt alloys. Biodegradable implants gradually replace native bone tissue, reducing the need for additional surgeries and improving patient recovery. However, non-biodegradable implants remain popular due to their stability, corrosion resistance, and biocompatibility. This study focuses on designing an implant plate for treating transverse femoral shaft fractures during the walking cycle. 
The primary objective is to conduct a comprehensive finite element analysis (FEA) of a fractured femur's stabilization using various biodegradable and nonbiodegradable materials. The study assesses the efficacy of different implant materials, discusses implant design, and identifies the optimal materials for femoral stabilization. Results indicate that magnesium alloy is superior among biodegradable materials, while titanium alloy is preferred among non-biodegradable options. The findings suggest that magnesium alloy is the recommended material for bone implants due to its advantages over non-degradable alternatives.

Synthesis methods of Mg-based scaffolds and their applications in tissue engineering: A review

Repair and regeneration of damaged tissues due to disease and accidents have become a severe challenge to tissue engineers and researchers. In recent years, biocompatible metal materials such as stainless steels, cobalt alloys, titanium alloys, tantalum alloys, nitinol, and Mg alloys have been studied for tissue engineering applications; as suitable candidates in orthopedic and dentistry implants. These materials and their alloys are used for load-bearing and physiological roles in biological applications. Due to the suitable conditions provided by a porous material, many studies have been performed on the porous implants, including Mg-based scaffolds. Mg alloy scaffolds are attractive due to some outstanding features and susceptibilities, such as providing a cell matrix for cell proliferation, migration, and regeneration, providing metabolic substances for bone tissue growth, biocompatibility, good biodegradability, elastic modulus comparable to the natural bone, etc. Accordingly, in the present study, a general classification of all the production methods of Mg-based scaffolds is provided. Strengths and weaknesses, the effect of the production approach on the final properties of scaffolds, including mechanical and biological capabilities, and the impact of alloying elements and process parameters have been reviewed, and discussed. Finally, the manufacturing methods have been compared and the upcoming challenges have been stated.

One step glow-discharge electrolysis-based preparation of Al doped Ni-Co layered double hydroxide/ graphene oxide as supercapacitor electrode material

Nickel-cobalt layered double hydroxides (LDHs) are promising materials for supercapacitor electrodes; however, they face challenges in terms of cycling stability and rate capability owing to agglomeration and low conductivity. In this study, Ni(III)CoAlx-LDH/GO with an extended layer spacing and excellent electronic conductivity was synthesized by one-step glow discharge electrolysis. A nickel–cobalt alloy was used as the anode, a graphite rod as the cathode, and sodium chloride as the electrolyte. In addition, incorporating an appropriate amount of aluminum chloride into the electrolyte can alter the microstructure of the electrode material, leading to enhanced electrochemical performance. Ni(III)CoAl0.2-LDH/GO, synthesized using 0.2 g AlCl3, demonstrated exceptional electrochemical performance of 1014C g−1 at 2 A/g. At a current density of 5 A/g, the capacitance retention rate was 85.3 % after 10,000 cycles, indicating strong cyclic stability. Moreover, an asymmetric supercapacitor built with Ni(III)CoAl0.2-LDH/GO as the anode and commercial activated carbon as the cathode achieved a specific capacitance of 146.2F/g at a current density of 1 A/g. This device demonstrated outstanding circular stability, retaining 85.07 % of its capacitance after 10,000 cycles. In addition, the device achieves relatively high energy density and power density (energy density of 66.63 Wh kg−1 at a power density of 1022.23 W kg−1). This study introduces a novel synthesis method for the preparation of high-performance electrode materials aimed at advancing energy storage devices.

Tensile Strength Property with PdCo-Cu Multi-Layer Lamination and Heat Treatment of MEMS Probe for Probe Card

Cantilever wire probe card has limited to transport high-speed signal because of long wire but it is suitable for inspecting high-current and high voltage semiconductor such as wide band gap (WBG) power semiconductors.Superior mechanical property of a probe card wire is in demand because it is respectively used wafer inspection with in and out pad on the top surface of the power semiconductor wafer. Therefore, in this study, tensile specimens of micro electro-mechanical systems (MEMS) probe alternatively layered and electroplated with palladium (Pd)-cobalt (Co) alloy layers and copper (Cu) layers. MEMS probe was also measured tensile strength and elongation with multi-lamination and heat treatment conditions. Additionally, fractography of fracture surface after tensile test were analyzed using a scanning electron microscope (SEM). As the number of PdCo-Cu multi-layer increased, 11, 15 and 21 layered specimens showed higher tensile strength and longer elongation than 5 layered specimens because of the increase of laminated interface of PdCo and Cu. 7 layered specimen after isothermal aging had higher tensile strength and longer elongation than before isothermal aging. In 5, 11, 15 and 21 layered specimens, the fracture surfaces of tensile test specimens without aging treatment showed a ductile-brittle mixed fracture mode. Fracture surfaces of 7-layered specimen before and after isothermal aging showed a ductile-brittle mixed fracture mode.

Ремонт деталей авіаційних двигунів із жароміцних нікелевих сплавів із застосуванням адитивних плазмових технологій

In order to improve the maintainability of aircraft engine parts, the article examined the use of additive technologies in repairs. The article establishes that the use of additive technologies by the method of plasma surfacing in the repair of aircraft engine parts, such as turbine blades, sealing discs, NA parts, is very promising and will significantly increase the percentage of parts and assemblies restored after operation, which have a significant area of damage. Turbine blades are made of nickel heat-resistant alloys with a polycrystalline structure (ЖС6К-ВИ, ЖС6У-ВИ), or from alloys with directional crystallization (ЖС32-ВИ, ЖС26-ВИ). After operating for more than 6 thousand hours, in addition to the operational wear of the ends and side walls of the shroud flanges, thermal fatigue cracks up to 6 mm deep are observed on the blades received for repair. The technology of argon-arc surfacing and the surfacing materials existing for this process do not provide the heat-resistant properties of the restored surface necessary for the operation of the blades. The solution to the problem was achieved through the use of a compressed arc source with precision adjustment of the welding current and mechanization of the supply of filler material (powder), which would make it possible to surfacing with a limited penetration depth and, accordingly, mixing the deposited material with the base metal. The developed technology made it possible to restore damaged sections of blades after operation (shroud flanges, labyrinth scallops, z-shaped profiles and airfoil ends) on heat-resistant alloys using filler material equal to the strength of the base metal. For this process, powders of nickel and cobalt alloys with a fraction of +63...-160 microns are used, obtained by atomization with a jet of inert gas (argon). The main powders used are ЖС32-ВИ, ЖС6К-ВИ, В3К, Stellite 12, Stellite 6, ХТН61. Disc material – ЭП742-ИД. Working medium, air, oil and combustion products. The maximum heating temperature of labyrinth scallops is up to 680 ºC at a maximum medium pressure of up to 1.47 MPa. The maximum peripheral speed of the scallop end is 251 m/s. Material of seal mating parts ЭИ435 (cell δ = 0,1 mm). When developing the technology, the successful experience of restoring labyrinthine scallops of turbine blades was taken into account. The restoration of the labyrinthine ridges of the disk was carried out using a compressed arc source with precision control of the welding current and a robotic installation, which included a robot for moving the plasma torch and a manipulator for rotating the disk. This made it possible to carry out surfacing with a limited penetration depth and obtain a uniformly directed bead over the entire diameter of the disk. Testing of the restored disk in order to verify its performance was carried out as part of a run-in aircraft engine. To do this, after the next assembly of the run-in engine, the disk was installed in the MPT rotor. The test was carried out in 5 cycles, the duration of each cycle was 15 hours. No wear of the labyrinth ridges or cracks was detected. The functionality of the restored disk has been confirmed. NA parts are made of heat-resistant, low-aging, high-chromium nickel-based alloy ЭП648-ВИ. They operate in hot engine conditions at temperatures up to 900'C. As a result of operation, both end surfaces and flat surfaces in the tract area are subject to wear. To restore parts of the NA, the technology of additive growth by the method of microplasma powder surfacing was used. To confirm the operability of restored parts, a set of studies of samples grown using the same repair technology was conducted. At the same time, it was established that the chemical composition of the deposited metal corresponds to the requirements of the technical conditions-» the microstructure of the deposited metal after heat treatment corresponds to the normal heat-treated state of the alloy ЭП648-ВИ (ХН50ВМТЮБ-ВИ), the level of mechanical properties of the grown alloy with subsequent serial heat treatment (aging at 700ºC, exposure -16 hours) is not lower than the forging level used in serial production of the part.

Nonlinearity association of blood cobalt with the risk of anemia among middle-aged and older adults: National Health and Nutrition Examination Survey

ABSTRACT Objective The use of cobalt alloys in medical implants poses a high risk of cobalt exposure, yet there is a lack of evidence regarding the association between blood cobalt levels and anemia. This study aimed to explore the link between blood cobalt levels and the onset of anemia and to identify potential threshold levels of blood cobalt that could affect anemia. Methods The US National Health and Nutrition Examination Survey data from 2017 to 2020 were analyzed for this cross-sectional study. This study primarily employed multivariate logistic regression, stratified interaction analysis, restricted cubic splines (RCS), and threshold effect analysis to explore the relationship between blood cobalt concentration and anemia. Results The study included 5510 participants and among them 12.2% were diagnosed with anemia. Logistic regression model indicates a positive correlation between blood cobalt levels and the risk of anemia. RCS shows that the relationship between ln cobalt concentration and anemia was non-linear (J-shaped). The ln cobalt inflection point was approximately 0.81. The odds ratio of anemia with ln cobalt ≥ 0.81 was 4.00 (95% CI: 2.95–5.43, p < 0.001), the odds ratio of anemia with ln cobalt < 0.81 was 0.73 (95% CI: 0.45–1.18, p = 0.201). Conclusions The analysis unveiled a non-linear relationship, indicating that elevated blood cobalt levels were linked to a heightened likelihood of developing anemia in middle-aged and older adults; the cut-off value of ln cobalt was approximately 0.81. The findings of this study warrant further investigation.

Determination of the geometric parameters of the defects based on the tomographically obtained data and their influence on the fatigue behavior of the S960 with laser cladded protective layers

This article deals with identifying defects of layered high strength steel materials with the help of tomography measurement. Test samples were made of S960 High Strength Steel to which layers of either aluminium bronze, hardchrome, cobalt alloy or stainless steel were applied by a laser cladding technology. The experimental campaign included a study of morphometric parameters of internal defects in and near the bi-material interface region using X-ray micro-tomography and their potential influence on the fatigue behavior during a three-point bending test.

A Tribological Study of CrN and TiBN Hard Coatings Deposited on Cobalt Alloys Employed in the Food Industry

In this work, a comparative study of the tribological performance of two hard coatings, CrN/TiBN, was conducted for research purposes and industrial applications in food products, particularly for food packaging into cans using the double hermetic sealing process. CrN and TiBN coatings were successfully deposited on a base-cobalt metal substrate of a CoCrW commercial alloy using physical vapor deposition by arc evaporation (AEPVD) technology to improve the tribological properties of the commercial alloy, including wear and corrosion resistance, lower coefficient of friction, and overall durability. This research focuses on conducting scratch and abrasion wear resistance tests in dry conditions; specifically, it pursues to evaluate the wear corrosion properties, known as tribocorrosion performance, on CrN/TiBN hard coatings. The experimental results show that the CrN coating (2.9 μm) is slightly thicker than the TiBN coating (2.7 μm), with a 47 N critical load. It also shows a lower coefficient of friction (CoF) in a dry environment, while the TiBN coating showed total detachment and a high coefficient of friction in a dry environment condition. Tribocorrosion testing in brine aqueous solution indicated that CrN coating shows a high friction coefficient with a higher open circuit potential value (Ecorr), and TiBN shows the lowest corrosion potential (Ecorr) and the lowest friction coefficient. This suggests that CrN could provide better corrosion protection for commercial cobalt alloys and improve tool performance during the food canning process in brine environments.

Protein-metal interactions due to fretting corrosion at the taper junction of hip implants: An in vitro investigation using Raman spectroscopy

Modular hip implants are a clinically successful and widely used treatment for patients with arthritis. Despite ongoing retrieval studies the understanding of the fundamental physico-chemical mechanisms of friction and wear within the head-taper interface is still limited. Here, we Raman-spectroscopically analyze structural features of the biotribological material which is formed within the taper joint between Ti6Al4V and low-carbon cobalt alloy or high-nitrogen steel surfaces in in vitro gross-slip fretting corrosion tests with bovine calf serum. As a function of the fretting duration, we investigate short and long aliphatic chains and their adsorption behavior on the cobalt- and steel-type surfaces. Using the intensity and frequency shifts of the amide I and III Raman bands, we furthermore identify progressive protein folding and unfolding including the secondary structures of α-helix, β-sheet, and random-coil configuration as well as the formation of proteinaceous clusters depending on the hydrophilicity of the metallic surfaces. We additionally find a mixture of chromates and iron oxides with tryptophan and tyrosine at the worn cobalt alloy and high-nitrogen steel surfaces, respectively. Also, for long fretting duration, sp2 hybridized amorphous carbon is formed due to fretting-induced cleavage of proteins. Statement of significanceDespite efforts enhancing the biomedical tribology of hip implants, the impact of the organic environment on friction and wear at the femoral head-stem taper interface is limitedly understood. Using Raman spectroscopy we resolve structural changes within the biotribological material agglomerated at biomedical-grade metal alloys due to metal-organic interactions during in vitro fretting corrosion tests. Adsorption of short and long aliphatic chains, progressive protein (un)folding and proteinaceous cluster formation depend to a distinguishable extent on the fretting duration and type of alloy. Chromates and iron oxides are mixed with tryptophan and tyrosine, and amorphous carbon is formed resulting from a fretting-induced cleavage of serum proteins. Such information spectroscopically gleaned from biotribological material are vital to improve the design and performance of taper junctions.

Mechanical and microstructural profiling of additively manufactured cobalt–nickel functional gradient structure

In this study, a functional gradient material (FGM) structure composed of a nickel alloy (IN718), and a cobalt alloy (CoCrMo) was additively manufactured using a co-axial powder-fed laser-directed energy deposition (L-DED) system. The high manufacturing flexibility of L-DED enabled the seamless deposition of IN718-CoCrMo FGM structure through interfacial bonding driven by thermal gradient and cool-down mechanisms. Microscopic analysis confirmed the absence of cracks or delamination in the CoCrMo-IN718 interfacial bonding region. The SEM-EBSD microstructural analysis and micro-hardness testing were performed on the as-printed CoCrMo-IN718 FGM primarily to correlate the hardness properties-microstructural grain phase morphology between the parent alloys and their interfacial bonding region. It was observed that the average hardness of the CoCrMo-IN718 interface zone (322.83 HV1) fell between IN718 (268.67 HV1) and CoCrMo (359.75 HV1) regions. The EBSD analysis reports indicated that along the build direction of CoCrMo-IN718 FGM, the preferential grain orientation aligned in [100] with grain structure transitioning from equiaxed → columnar → elongated columnar dendrites → equiaxed grain, predominantly comprised of face-centered cubic (FCC)-gamma (γ) phase crystal structures. Relatively, coarser grain structures were observed in the interface bonding region, attributed to the analogous crystallography space groups, and prolonged localized thermal gradients.

Study of the Influence of Ferromagnetic Impurity Concentration on Magnetic Properties of Binary Palladium–Cobalt Alloy

A comparative study of the magnetic properties of a palladium–cobalt alloy with an impurity content of up to 0.05 at. % was made using calculations based on the density functional theory and experimental methods. It was found that the alloys had ferromagnetic ordering, which depended on the impurity concentration. At very low concentrations, less than 1 at. %, the magnetic moment per impurity atom can reach 25 µB.

Comparative investigation on the microstructure and corrosion properties of surfacing cobalt alloys by various methods

This study applies three different welding methods, namely tungsten inert gas (TIG) welding, laser welding, and plasma arc welding, to perform cobalt alloy surfacing on austenitic stainless steel substrates, and compares their microstructure and corrosion properties. The results reveal that samples obtained through all three methods exhibit excellent metallurgical bonding between the austenitic stainless steel substrate and the cobalt alloy surfacing layer, with no observed defects such as cracks, pores, or inclusions. Among them, the cobalt alloy surfacing layer produced by laser welding shows a finer and more uniform microstructure, displaying a distinct growth direction along the surfacing direction away from the interface. Additionally, electrochemical polarization curve testing demonstrates that the corrosion resistance of the laser-welded surfacing layer surpasses that of TIG welding and plasma arc welding, exhibiting a lower corrosion rate. This study offers valuable insights into the selection of cobalt alloy surfacing welding methods on austenitic stainless steel substrates and the evaluation of the corrosion properties for the cobalt alloy surfacing layer, providing essential guidance for engineering practices in the power plant valves.

The Impact of Cryogenic Temperatures on the Hardness and Tribological Properties of Cobalt Alloys

The Impact of Cryogenic Temperatures on the Hardness and Tribological Properties of Cobalt Alloys

Cobalt nanoparticles attenuate microplastic-induced vascular endothelial injury via Nrf2 pathway activation

The widespread utilization of plastic and cobalt alloy products in industries and medicine has led to the increased presence of their degradation byproducts, microplastics (MPs), and cobalt nanoparticles (Co NPs), in the environment and organisms. While these particles can circulate throughout the body via the circulatory system, their specific adverse effects and mechanisms on the vascular system remain unclear. Employing scanning electron microscope (SEM) analysis and other methodologies, we demonstrate the potential adsorption and aggregation phenomena between MPs and Co NPs. In vitro experiments illustrate that ingestion of either MPs or Co NPs compromises vascular endothelial cell function and induces the generation of reactive oxygen species (ROS). Notably, this effect is markedly attenuated when a combination of MPs and Co NPs is administered compared to MPs alone. Additionally, zebrafish experiments validate our in vitro findings. Mechanistic studies have demonstrated that both MPs and Co NPs induce aberrant Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling. Intriguingly, a weaker activation level is observed when these agents are administered in combination compared to when they are administered individually. Our study provides novel insights into the interaction between MPs and Co NPs and their detrimental effects on vascular endothelial cells.

Powder Bed Fusion Techniques in Metal 3D Printing: A Review

The use of 3D printing (additive manufacturing) with metal has grown significantly in demand recently, greatly reducing the time and expense required to produce complex interconnected metal components. This method minimizes material wastage, facilitates material recycling, and eliminates the need for support materials. Among the various Metal Additive Manufacturing techniques, Powder Bed Fusion (PBF) processes stands out as the most prevalent for manufacturing parts. Within the realm of PBF, electron beam melting technique, selective laser sintering technique, and selective laser melting technique are the primary methods employed. Selective laser melting and selective laser sintering operate without the need for any special conditions, unlike EBM, which necessitates a vacuum environment. Regarding the choice of materials, laser melting/sintering processes are suitable for almost all types of metals except those which surpasses beam melting capabilities. While electron beam melting is constrained to a few materials such as titanium alloys, cobalt and chromium alloys, and nickel alloys, whereas selective laser melting and sintering allows for a broad range of materials, including iron and steel alloys. However, electron beam melting exhibit the ability to process brittle materials that would typically be challenging for melting and sintering through laser. Nevertheless, the ductility, yield testing, and ultimate testing of materials created through EBM are inferior to those processed by laser methods. Although all PBF techniques excel at creating complex structures, finishing products to have a smooth surface directly over a rough surface remains a subject of ongoing research. To attain suitable mechanical properties such as hardness, tensile strength, and endurance, critical process factors include power of laser or beam, speed for scanning, density for powder bed, thickness of laser or beam, and material characteristics. Inadequate material selection coupled with incorrect process settings can lead to issues such as porosity, slag formation, and other flaws.

Carbon-Monoxide Assisted Synthesis of Cobalt-Nickel Phosphides for Hydrogen Evolution Reaction

Alkaline water electrolysis is a method for production of hydrogen as an alternative source for renewable energy. This method can be completely free of greenhouse gas emissions if it is paired with another alternative energy source, such as solar energy or wind power, to provide the necessary electricity to drive the reaction. Water electrolysis requires catalysts to make that necessary amount of electricity low enough for competitive hydrogen production in the current market. Vast numbers of studies have been performed in an attempt to fill this need for cost-effective catalysts for water electrolysis. This work focuses on the development of synthesis methods for cobalt-nickel phosphide catalysts for the hydrogen evolution reaction (HER) for water electrolysis in alkaline media. The methods for preparation of the catalysts are explored for cobalt, nickel, and cobalt-nickel alloy phosphides in the presence of carbon monoxide as a shape-controlling capping agent. Depending on the condition of carbon monoxide addition, the reaction results in high vs. low-aspect ratio nanorods or nanospheres for mono- or bimetallic cobalt-nickel phosphide nanostructures. These phosphides are then subjected to evaluation for HER via cyclic voltammetry and linear sweep voltammetry to study the effects of morphology on their HER activity. Materials characterization such as XRD, TEM, and ICP-MS are performed before the HER electrochemical evaluation for better understanding of the structure-activity relationship. The catalytic activities of these phosphides are also compared to the noble metal benchmark HER catalyst Pt/C in the same environment at their equal mass loadings. The best-performing phosphide is further tested for HER at increased mass loadings to study the effects of catalyst loadings on the mass transport and thus the activity. Further TEM characterization is performed on the most active catalyst after HER to evaluate morphological stability. It is found that in order to achieve an overpotential at the current density of 100 mA/cm2 comparable to Pt/C for 50 μg/cm2, the necessary loading for the phosphide is 250 µg/cm2.

Effects of boron on microstructure, wear and corrosion properties of external magnetic field assisted laser metal deposition coatings

Coatings with different boron content were prepared by magnetic field-assisted Co-based laser metal deposition on 300 M ultra-high strength steel. The effects of boron content on the magnetic properties, mechanical properties, friction and wear properties, and corrosion resistance of the coating were investigated. The research results indicate that adding 6 wt% of boron to cobalt alloy in a 35 mT alternating magnetic field is beneficial for refining the microstructure, which can improve the mechanical properties of the coating. This research also discusses the effect of boron content on the wear and corrosion resistance of the coating. The results show that adding boron content enhances the magnetostrictive effect, and reduces the elastic modulus of the laser metal deposition coating while ensuring its hardness, thereby improving the wear and corrosion resistance of the laser metal deposition layer. The hardness of the coating can reach 1215 HV. The friction coefficient and corrosion current density of the coating are reduced by 26.9% and 60.2% respectively compared with the substrate. This work can help promote the application of laser metal deposition technology, reduce costs, and ensure performance.

Fatigue life of S960 high strength steel with laser cladded functional surface layers

This study evaluates the fatigue life of S960 high-strength steel with laser-cladded layers of aluminium bronze, hard chrome, cobalt alloy, and stainless steel, using three-point bending tests. Our results demonstrate that while these cladded layers offer potential for enhanced surface properties, they generally reduce the material’s fatigue life due to alterations in the heat-affected zone and the introduction of microstructural defects at layer interfaces. The extent of fatigue life reduction varies with the type of cladded layer, highlighting the importance of optimizing laser cladding parameters to minimize detrimental effects and improve component longevity.

Alloy modification and ultrasonic-assisted milling of wear-resistant alloys with defined surfaces

The reduction of CO2 emissions is closely linked to the development of highly efficient and economical steel components in plant and process engineering. To withstand the high combined corrosive, tribological, thermal, and mechanical stresses, wear-resistant coatings tailored to the application and steel grade are used. In addition to the increasing demand to substitute conventional cobalt alloys with nickel alloys, there is also a growing need for defined or functional surfaces of high integrity. Due to high tool wear, milling operations required to produce the complex geometries of the components are often not economically feasible for SMEs. By means of alloy modification of the filler metals for nickel-based plasma build-up welded wear-resistant coatings and by the use of innovative ultrasonic-assisted milling processes more favourable machinability shall be achieved without reducing the wear protection potential. In this paper, the influence of the microstructure and precipitation morphology adjusted by means of alloy modification on the machinability is investigated. This is done based on a wear protection alloy NiCrMoSiFeB (trade name: Colmonoy 56 PTA) typically used for screw machines, which substitutes conventional CoCr alloys (Stellite). Metallurgical investigations and in-situ measurements of occurring process forces and temperatures at the tool cutting edge during milling as well as subsequent investigations of tool wear and surface integrity allow a detailed analysis and correlation between microstructural properties and machinability. For the cast samples, a clear change in the microstructure and hardness can be seen through the addition of Al, Ti, or Nb. These differences lead to an improvement in the machining process for Nb. Al and Ti cause long-needled or star-shaped precipitations and hardness increases, which lead to higher cutting forces and increased tool wear.

Study of the Influence of Ferromagnetic Impurity Concentration on Magnetic Properties of Binary Palladium–Cobalt Alloy

Study of the Influence of Ferromagnetic Impurity Concentration on Magnetic Properties of Binary Palladium–Cobalt Alloy