Phase Composition Research Articles

Deep Cryogenic and Thermal Aging Treatments of Ti–5Al–5Mo–5V–3Cr Alloy Additively Manufactured by Powder Bed Fusion–Laser Beam

The properties of 3D‐printed components via powder bed fusion–laser beam (PBF–LB) depend strongly on the processing parameters, particularly due to the rapid solidification conditions involved. In this study, an innovative post‐treatment strategy combining deep cryogenic treatment (DCT) and thermal aging treatments are introduced to enhance the properties of Ti–5Al–5V–5Mo–3Cr alloy (Ti‐5553) alloy fabricated by PBF–LB. In the results, it is revealed that DCT of as‐built material can refine the grain size and introduce defects and sub‐grain boundaries, thereby improving strength and ductility without significantly altering the microstructure or phase composition. However, applying DCT after aging can significantly improve ductility and maintain strength, primarily by refining β‐phase grains. Conversely, thermal aging followed by DCT of as‐built materials tends to increase strength at the expense of ductility, due to the formation of the ω phase and defects induced by the cryogenic treatment that in turn promote the development of more abundant and finer α phase within grains during aging. In the findings of this research, significant insights and valuable methodologies are offered for optimizing the mechanical properties of Ti‐5553 alloy manufactured by PBF–LB via an extra DCT following thermal aging.

Water-in-oil microemulsions with greener oil solvents as sustainable nanoreactors of biopolymer nanoparticles

Microemulsions have been widely used in multidisciplinary fields, yet reverse water-in-oil microemulsions are traditionally dispersed in petroleum-based oil solvents. For greener approaches, it should be also feasible to use less toxic, bio-based hydrocarbon solvents as continuous oil phase. Herein, reverse microemulsions in different alkanes, middle-chain alkanols, middle-chain esters or combinations of nonpolar solvent with alkanol are compared, using Aerosol-OT as common surfactant. As model of bio-based solvents, ethyl caprylate, isoamyl acetate and isoamyl alcohol are proposed as a more sustainable approach of oil solvents. Various characterization techniques were used to compare the properties and stability of reverse microemulsions for the different oil phase compositions, ranging from ternary phase diagrams to conductometry and turbidity titrations, micro-Differential Scanning Calorimetry and cryo-Scanning Electron Microscopy. As sustainable application, these microemulsions in bio-based solvents were proved suitable as template phase for the synthesis of cross-linked chitosan nanoparticles. The sizes of the resulting biopolymer nanoparticles were characterized by Dynamic Light Scattering and Atomic Force Microscopy, so that the effect of different crosslinkers and different the oil phase compositions was also compared. Thus, the use bio-based alkyl esters can provide similar microemulsion properties as the conventional alkanes, especially when using a combination of nonpolar solvents with alkanols.

Development and validation of the RP-HPLC method for quantification of tavaborole.

The stability-indicating approach for tavaborole quantification was developed and validated to establish a precise, linear, accurate, and robust HPLC method. The development section includes optimizing the detection wavelength, the mobile phase ratio, and the type of column used to achieve the best possible separation and sensitivity for analysis. The chromatographic conditions were established, considering peak symmetry, resolution, and retention time. The mobile phase composition, comprising a buffer: acetonitrile (75 : 25, %v/v), with an injection volume of 15 μL, showed suitable elution and recovery at 265 nm. A constant column oven temperature of 35 °C and a 1 mL min-1 flow rate were maintained. The pH of the buffer was changed to 3.0 by using orthophosphoric acid. Linearity was observed from 5 to 1000 ppm (r2 = 1.00000). The capacity (retention) factor (k) of 3.43 was observed, indicating significant interaction and good separation. Forced degradation (FD) or stress tests were performed for chemical and physical photolytic stress conditions, and the results observed were within the specified limits. The stability in the analytical solution was observed for up to 35 hours at 5 °C, confirming the stability of the solution. Validation of the developed HPLC method confirmed the system's suitability, precision, linearity, accuracy, FD, robustness, and results. All validation criteria for the technique were within acceptable limits.

Preparation and characterization of innovative cement mortar incorporating fatty acid/expanded graphite composite phase change material for thermal energy storage

To explore the application of phase change energy storage materials in building energy conservation, in this study, an innovative composite thermal energy storage cement mortar (CTESCM) was developed using lauric acid–palmitic acid/expanded graphite (LA-PA/EG) as the composite phase change material (CPCM). Seven different CTESCM test blocks with different CPCM mass contents were prepared. The thermal characterization of the CTESCMs was achieved using a differential scanning calorimeter (DSC), a thermogravimetric analysis (TGA), thermal conductivity tests, and heat storage/release tests. The physical behavior was assessed using density, mechanical performance was assessed using compressive strength, and the microstructure was observed using a scanning electron microscope (SEM). The results indicate that the phase transition temperature of the CTESCMs was lower than that of the LA-PA/EG CPCM, and the latent heat consistently decreased with the decrease of the CPCM mass content. With the addition of the CPCM, which had a low-density porous structure, the thermal conductivity, density, and compressive strength of the CTESCMs decreased. CTESCM with a mass fraction of 20%C (20% cement) CPCM can be used for building energy conservation such as floor radiation heating systems.

Complex Modification of the Surface Layer of a High-Entropy Al-Cr-Fe-Co-Ni Alloy by Electron-Ion-Plasma Treatment

Using the technology of wire-arc additive manufacturing (WAAM – wire arc additive manufacture), a high-entropy alloy (HEA) of non-equiatomic composition Al, Cr, Fe, Co, Ni was manufactured. Using the methods of modern physical materials science, an analysis of the elemental and phase composition, defective substructure, mechanical and tribological properties of the HEA surface layer, formed as a result of complex modification, combining the deposition of a film (B + Cr) and irradiation with a pulsed electron beam in an argon medium, was carried out. In the initial state, the alloy has a simple cubic lattice with a lattice parameter of 0.28795 nm; the average grain size of the HEA is 12.3 µm. Chemical elements (at. %) 33.4 Al; 8.3 Cr, 17.1 Fe, 5.4 Co, 35.7 Ni, which form HEA, are distributed quasi-periodically. The irradiation regime was revealed (energy density of the electron beam ES = 20 J/cm2, pulse duration 200 µs, number of pulses 3 pulses, frequency 0.3 s more than 5 times), allowing to increase microhardness (almost 2 times) and wear resistance (more than 5 times), reduce the coefficient of friction by 1.3 times. Regardless of the value of ES, HEA is a single-phase material and has a simple cubic crystal lattice. High-speed crystallization of the surface layer leads to the formation of a subgrain structure (150–200) nm. It is shown that an increase in the strength and tribological properties of HEA is due to a significant (4.5 times) decrease in the average grain size, the formation of particles of chromium and aluminum oxyborides, and the incorporation of boron atoms into the crystal lattice of HEA.

Development of δ-Bi2O3/Bi2SiO5 heterostructures based on biogenic silica for photocatalytic treatment from organic pollutants

ABSTRACT δ-Bi2O3/Bi2SiO5 heterostructural photocatalysts with different contents of bismuth in samples (X-Bi-Si, where X = 10–60% Bi2O3) were prepared by the facile sol–gel method using bismuth nitrate and biogenic silica from rice husk biomass as precursors. FT-IR, scanning electron microscope, XRD, energy-dispersive X-ray fluorescence, and UV–Vis methods were systematically used to characterize the as-obtained materials. The photodegradation of methyl orange (MO) in neutral aqueous solutions (pH (6.8)) under UV irradiation was studied to evaluate their photocatalytic activities. The phase composition, morphology, and photocatalytic activity of the samples depended on the content of bismuth oxide in the samples. The maximum degree of MO degradation was 45% for 50-Bi-Si samples containing photoactive δ-Bi2O3 and Bi2SiO5 phases.

Influence of a Constant Magnetic Field on the Parameters of the Magnetoplastic Effect in Aluminum Alloy B95pch

The present work is devoted to the comprehensive experimental study of the magnetoplastic effect found in the aluminum alloy B95pch aged in a weak constant magnetic field. The data on chemical composition of aluminum alloy B95pch, modes of thermal and thermomagnetic treatments and main experimentally observed regularities of changes in values of microhardness, modulus of elasticity of separate local areas and phase composition of aluminum alloy B95pch, aged at temperature 140°С, time from 2 to 8 h, in a constant magnetic field with intensity 557.0 kA/m and in its absence are presented. It was found that the constant magnetic field significantly affects the strength properties and structure of aluminum alloy B95pch. The negative magnetoplastic effect has been detected, the value of which is 21%. It is observed that the constant magnetic field does not significantly affect the average grain size, however, the size and number of observed foreign inclusions within the grain become significantly smaller compared to aging in the absence of magnetic field. In addition, the imposition of the constant magnetic field on the phase formation process leads to the formation of a more distorted structure: the half-width of diffraction lines becomes wider. The results of microhardness and modulus of elasticity measurements of aluminum alloy B95pc were found to be correlated.

Carbide slag and sodium metasilicate synergistic activation of sludge ash-based alkali-activated materials: Towards a cleaner activation approach

Traditional activators such as sodium hydroxide and sodium silicate are commonly used in the preparation of alkali-activated materials; however, their significant environmental impact, high cost, and operational risks limit their sustainable use in treating solid waste. This study explores the innovative use of carbide slag (CS) and sodium metasilicate (NS) as alternative activators in the production of sewage sludge ash-based alkali-activated materials (SSAM) with the aim of reducing the carbon footprint of the preparation process. The results demonstrate that CS effectively activates the sewage sludge ash, enhancing the compressive strength of the SSAM to 40 MPa after curing for 28 d. When used in conjunction with NS, it synergistically improves the mechanical properties. Furthermore, the microstructure and phase composition of the SSAM are characterized. Increasing the quantities of CS and NS accelerates the dissolution of the precursor materials, promoting the formation of a higher quantity of hydration products. This significantly reduces the number of voids and defects within the samples, further enhancing the densification of the microstructure. Environmental assessments reveal that CS and NS offer substantial sustainability benefits, confirming the feasibility of activating SSAM using these materials. This approach provides a less energy-intensive and more environmentally friendly alternative to conventional activation methods and presents an effective strategy for managing large volumes of sewage sludge ash and CS.

Electrochemical and statistical study of Nickel ion assessment in daily children intake samples relying on magnesium aluminate spinel nanoparticles

Lately, children's daily consumption of some products, such as cereals and candies, has been rising, which provides a compelling rationale for determining any metallic substances that may be present. Monitoring the concentration of certain metals, like nickel, in these products is necessary due to medical issues in humans when consumed regularly. So, in this work, a novel and highly selective carbon paste as a Ni(II) ion-selective sensor was prepared and investigated using ceramic magnesium aluminum spinel nanoparticles as the ionophore and tritolyl phosphate (TOCP) as a plasticizer. A modified co-precipitation method was used to synthesize the spinel nanoparticles. X-ray diffraction, scanning electron microscope with EDAX, transmission electron microscope, and BET surface area were used to determine the phase composition, microstructure, pores size, particle size, and surface area of the synthesized nanoparticles. The spinel nanoparticle was found to have a nano crystallite size with a cubic crystal system, a particle size ranging from 17.2 to 51.52 nm, mesoporous nature (average pore size = 8.72 nm), and a large surface area (61.75 m2/g). The composition ratio of graphite carbon as a base: TOCP as binder: spinal as ionophore was 67.3:30.0:2.7 (wt%) based on potentiometric detections over concentrations from 5.0 × 10−8 to 1.0 × 10−2 mol L−1 with LOD of 5.0 × 10−8 mol L−1. A measurement of 29.22 ± 0.12 mV decade−1 over pH 2.0–7.0 was made for the Nernstian slope. This sensor demonstrated good repeatability over nine weeks and a rapid response of 8 s. A good selectivity was shown for Ni(II) ions across many interferents, tri-, di-, and monovalent cations. The Ni(II) content in spiked real samples, including cocaine, sweets, coca, chocolate, carbonated drinks, cereals, and packages, were measured. The results obtained indicated no significant difference between the proposed potentiometric method and the officially reported ICP method according to the F- and t-test data. In addition to utilizing ANOVA statistical analysis, validation procedures have been implemented, and the results exceed the ICP-MS methodology.

Phase interface engineering enables state-of-the-art half-Heusler thermoelectrics

In thermoelectric, phase interface engineering proves effective in reducing the lattice thermal conductivity via interface scattering and amplifying the density-of-states effective mass by energy filtering. However, the indiscriminate introduction of phase interfaces inevitably leads to diminished carrier mobility. Moreover, relying on a singular energy barrier is insufficient for comprehensive filtration of low-energy carriers throughout the entire temperature range. Addressing these challenges, we advocate the establishment of a composite phase interface using atomic layer deposition (ALD) technology. This design aims to effectively decouple the interrelated thermoelectric parameters in ZrNiSn. The engineered coherent dual-interface energy barriers substantially enhance the density-of-states effective mass across the entire temperature spectrum while preser carrier mobility. Simultaneously, the strong interface scattering on phonons is crucial for curtailing lattice thermal conductivity. Consequently, a 40-cycles TiO2 coating on ZrNi1.03Sn0.99Sb0.01 achieves an unprecedented zT value of 1.3 at 873 K. These findings deepen the understanding of coherent composite-phase interface engineering.

Efficient hydrogen absorption and dehydrogenation of synergistically catalyzed Mg10Fe by MoS2 and Y2O3 via one-step synthesis and multistage regulation

To effectively deal with the long preparation period and low hydrogen absorption capacity issue of Mg-based hydrogen storage materials. One-step multistage control strategy and high-pressure hydrogenation have been employed to prepare Mg10Fe-M (M = MoS2 or Y2O3 or both) composites. The phase composition, microstructure, morphology, non-isothermal dehydrogenation thermodynamics and isothermal dehydrogenation kinetics at different milling time (2, 4, 8 h) were explored, and the catalytic hydrogen absorption and discharge mechanism of Mg10Fe–MoS2–Y2O3 was proposed. The addition of MoS2 nanoflowers and Y2O3 powder can synergistically regulate and improve the hydrogenation capacity and dehydrogenation temperature of Mg10Fe. The hydrogen absorption and dehydrogenation of Mg10Fe–MoS2–Y2O3 in short time milling for 2 h are 3.64 wt% and 3.27 wt% respectively. After extending the milling time to 8 h, the thermodynamic and kinetic behavior of Mg10Fe-M (M = MoS2 or Y2O3 or both) is greatly improved. Kinetically, the hydrogenation or dehydrogenation capacity increases significantly, Mg10Fe–MoS2 doesn't need activation, and the hydrogenation capacity reaches 5.42 wt% at 623 K, with a yield of about 85.9 % in 60 min. Thermodynamically, the initial dehydrogenation peak temperature drops to about 310 °C, and the apparent activation energy also decreases significantly, among which Mg10Fe–MoS2–Y2O3 was 91.87 kJ/mol. These are attributed to the fact that MoS2 nanoflowers provide many active sites for H2 adsorption and H atom dissociation. Synchro-efficient synthesis and regulation of Mg-rich composite hydrogen storage materials are expected to shorten the synthesis cycle, improve the hydrogen storage performance, and lay a material foundation for the design and development of solid hydrogen storage devices.

High-Speed Steel Technology Substitution in Mining Machinery – an Experimental Study

The growth of mineral extraction in countries with a developed mineral resource sector under conditions of external restrictions requires the modernization of the domestic mining machinery – an indispensable condition of which is the replacement of technologies for the production of high-speed steels and machine tools. This research was aimed at experimental studies of microstructure, phase composition and microhardness distribution in the surface layer of the R6M5 high-speed steel samples after laser cutting, cold treatment and laser tempering. It was demonstrated that after laser cutting in the surface layer of the cut there was the carbide dissolution and enrichment of the metal matrix with carbon and alloying components, resulting in an increase of residual austenite content up to 50...60 %. After the cold treatment in liquid nitrogen the content of residual austenite decreased up to 7...9 %. The laser cut surface microhardness increased up to 1000...1100 MPa. At further laser tempering the dispersion hardening processes took place, as a result the V2C carbides appeared in the steel structure amounting to 4.7 %. The microhardness increased up to 10400...10600 MPa. The study showed the possibility of using the high-speed steel laser cutting not only as a separating operation, but also as a hardening treatment. The findings contribute to the technological support for the development of domestic mining machinery in terms of replacing imported high-speed steels and machine tools.

Study on mullitization of sillimanite group minerals and its effect on properties of the Al2O3‐SiC‐C gunning material

AbstractThis study aimed to compare and summarize the mullitization mechanism of the sillimanite group minerals and investigated its effect on the mechanical properties of Al2O3‐SiC‐C gunning materials. By comparing the phase composition and microstructure of kyanite, andalusite, and sillimanite at different temperatures, the mullitization mechanism of sillimanite group minerals was clarified. Furthermore, the Al2O3‐SiC‐C gunning materials with sillimanite group minerals addition were prepared by bauxite and fused brown corundum as aggregates, fused white corundum (≤0.045 mm), SiC (≤0.075 mm), α‐Al2O3 (≤10 µm), pitch sphere, SiO2 micropowder (≤2 µm) as a matrix, and silica sol as a binder. Then, the effect of the addition of sillimanite group minerals on the mechanical properties of Al2O3‐SiC‐C gunning materials was characterized. The results indicate that kyanite requires the lowest temperature for mullitization compared to andalusite and sillimanite. The mullitization process involves the migration of Al3+ and Si4+, resulting in a decrease in the lattice constant of sillimanite group minerals followed by the production of mullite and SiO2. Incorporating sillimanite group minerals into Al2O3‐SiC‐C gunning materials effectively controls their linear change rate after firing while enhancing their mechanical properties. Notably, the addition of kyanite yields superior performance in Al2O3‐SiC‐C gunning materials.

Development and Validation RP-HPLC Method for Estimation of Antidiabetic Drugs in Pharmaceutical Dosage Form

This study details the development and validation of an RP-HPLC method for estimating Canagliflozin and Metformin in pharmaceutical dosage forms. Canagliflozin, an SGLT2 inhibitor, and Metformin, an antihyperglycemic agent, were obtained from Arti Drug Pvt. Ltd. Marketed formulation Invokamet was sourced locally. Chromatographic separation was achieved on a C18 column (250 x 4.6 mm, 5 µm) using a mobile phase of Methanol: Water (80:20) with 0.1% ortho phosphoric acid at a 1.0 ml/min flow rate and detection at 254 nm. The retention times for Canagliflozin and Metformin were 8.183 min and 3.633 min, respectively. Method validation parameters included system suitability, accuracy, precision, and robustness. System suitability tests confirmed adequate resolution and repeatability. Accuracy was evaluated through recovery studies at 80%, 100%, and 120% concentration levels, yielding satisfactory results. Precision was demonstrated with intra-day and inter-day % RSD values below 2. Robustness was assessed by varying mobile phase composition and flow rate, showing consistent retention times and tailing factors. The method proved selective, accurate, precise, and robust, with a short run time, facilitating rapid quantification of samples. It is suitable for routine quality control analysis of Canagliflozin and Metformin in pharmaceutical formulations

Effect of Mo Content on the Structural, Mechanical, and Tribological Properties of New Zr-Nb-Mo Alloys Obtained by Combining Powder Metallurgy and Vacuum Arc Melting Methods

Considering the high demand for innovative solutions in medicine, a major increase in interest in biomaterials research has been noticed, with the most significant advancements in metals and their alloys. Titanium-based alloys are one of the most recognised in the scientific community but do not represent the only way to achieve optimal results. Zirconium alloys for medical applications are a novelty with significant research potential based on their outstanding properties, which may be of value for medicine. The aim of the present study was to obtain new biomedical Zr-Nb-Mo alloys with varying ratios of their respective elements—Zr and Mo—using combined powder metallurgy (PM) and arc melting (VAM) methods. The obtained samples underwent microstructure analysis using an optical microscope (OM) and a scanning electron microscope (SEM). The study of element distribution was conducted with energy dispersive spectroscopy (EDS), whereas the phase composition was determined using X-ray diffraction (XRD). Mechanical properties were examined with a Micro Combi Tester MCT3, whereas tribological properties were assessed with a TRN Tribometer, and Ringer’s solution was used as a lubricant. Additionally, the wear tracks of the studied samples were observed using the SEM. The research results indicated that increased Mo content conduced to microstructure refinement and homogeneity. Furthermore, the higher content of this element contributed to the growth of the HVIT, HIT, and EIT parameters, together with the improvement in the tribological performance of the alloys. XRD analysis revealed that the obtained samples were multiphase, and raising the Mo addition promoted the formation of new phases, including a ternary phase—Zr0.9Nb0.66Mo1.44 (Fdm). The chemical composition study showed uneven distribution of niobium and areas of uneven mutual distribution of zirconium and molybdenum.

Synthesis and in vitro bioactivity of sodium metasilicate-derived silicon-substituted hydroxyapatite

Structural alteration of synthetic implants aims to achieve better bioactivity, higher cellular response, and regulated degradability, all of which are critical criteria for a biomaterial to serve as a graft in bone regeneration. The aim of this work was to synthesize silicon-substituted hydroxyapatite and test its bioactivity in simulated body fluid (SBF) by proving the use of sodium metasilicate (Na2SiO3.9H2O) as an affordable precursor of silica. Thus, the study evaluated the in vitro bone-bonding capacity of hydroxyapatite (Ca10(PO4)6(OH)2) (HA) substituted with silicate ion (Ca10(PO4)6-x(SiO4)x(OH)2-x; SixHA). The SixHA with x = 0.4 was synthesized by utilizing a wet precipitation method with sodium metasilicate as a low-cost silica alternative for alkoxysilane precursors. The SixHA was then examined for properties such as morphology, elemental composition, phase composition, and the nature of chemical bonds using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffractometry (XRD), and Fourier transformed infrared spectroscopy (FTIR), respectively. An in vitro bioactivity experiment was also carried out by incubating the SixHA in simulated body fluid (SBF) at 36.5 °C for 7 and 14 days. The obtained results revealed the substitution of SiO44- for some PO43- groups in the hydroxyapatite structure. The SixHA nucleated more apatite crystals on its surface and demonstrated some degradability during the periods of immersion in SBF. The characteristics of the SixHA imply that it could be used as a graft in bone restoration applications, thus signifying that sodium metasilicate could serve as an economic silica source for silicon-substituted hydroxyapatite production.

Body composition and phase angle in rugby union athletes: A comparison between forward and back positions

IntroductionRugby union has been increasingly attracting a multitude of enthusiasts over the past years. Nevertheless, there is a need for a more profound understanding of body composition, particularly regarding body fluids, and phase angle by playing position in rugby union athletes. MethodsThis study aimed to compare body composition components and phase angle among rugby union athletes based on their playing positions (forwards vs. backs). The sample consisted of 26 male athletes from rugby union clubs in Florianópolis, Brazil. Body composition [fat mass, lean soft tissue mass (LSTM)], body fluids (total body water, intra and extracellular water, and their proportions) and phase angle were evaluated using dual emission X-ray absorptiometry and bioelectrical impedance analysis, respectively. Statistical analysis was carried out using the analysis of covariance to compare body composition, and phase angle between playing positions (forwards vs. backs). ResultsThe primary findings indicated that rugby union athletes playing as forwards demonstrated higher values for fat mass, FFBM, and body fluids (total body water, intracellular, and extracellular water) compared to those playing as backs (p < 0.01). No difference was observed between playing positions for the other variables. ConclusionsBody composition may vary depending on the playing position in rugby union athletes.

Corrosion Behavior of Al-Containing CoNiV Medium Entropy Alloy Coating Fabricated by Laser Cladding.

CoNiV medium entropy alloys (MEAs) have been widely recognized for their superior corrosion resistance. Nonetheless, their extensive application has been hindered by high production costs and complex fabrication processes. In this study, CoNiVAlx MEA coatings were synthesized on AISI 304 stainless steel substrates via laser cladding technology. The microstructure, phase composition, corrosion resistance, and corrosion mechanisms of the coatings were systematically investigated by using advanced characterization techniques, including optical microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffractometry, and electrochemical workstation analysis. The ratio of O2-/OH- in the passivation film of the coated surface exhibited a gradual increase with the addition of Al. The formation of the Al-containing precipitated phase L21 was observed at x = 0.3 and 0.4. The results demonstrated that moderate Al doping (x ≤ 0.2) enhanced corrosion resistance by improving the stability of the passivation film and reducing the thermodynamic tendency toward corrosion. In contrast, excessive Al doping (x > 0.2) led to the formation of the L21 phase, which increased the susceptibility to localized corrosion, thus compromising the overall corrosion resistance.

Long-term ablation behavior of Al4SiC4-YB4 modified Cf/ZrB2-SiC composites at 2600 °C

Long-term ablation behavior of Al4SiC4-YB4 modified Cf/ZrB2-SiC composites was characterized by air plasma torch at 2600 °C for 300 s. The phase composition and the microstructure evolution of the composites were investigated. The addition of YB4 promotes the formation of nano t-Zr0.92Y0.08O1.96 crystals, decreasing the phase transition stress in the oxide layer and reducing the volatilization of the glassy phase. However, the addition of Al4SiC4 reduces the melting point of Zr-based oxides and the viscosity of the oxide layer. Therefore, the air plasma torch blows the oxide layer away, leading to the increase of linear recession rate.

High-temperature erosion behavior of Al2O3 reinforced Inconel625 high velocity oxy-fuel sprayed and direct-aged composite coatings

In this study, Inconel625+30%Al2O3 (IN30AL) blended powders were sprayed on a commercially used boiler steel ASTM SA210 GrA1 using high-velocity oxy-fuel approach (HVOF). The microstructure, mechanical properties and elevated temperature erosion behavior of post-processed coatings and as-sprayed IN30ALcoatings were investigated. The elevated temperature erosion studies on IN30AL coatings both as-sprayed and post-processed were investigated at 900 °C temperature at two impact angles 30° and 90° using standard high temperature erosion test rig. Phase composition, interface of substrate/coating, and morphologies of eroded coatings were examined using x-ray diffraction, x-ray maps, scanning electron microscope, & energy dispersive spectrometer techniques. Compared with the as-sprayed IN30AL coatings, the heat-treated coatings have refined microstructure, better mechanical properties which improve the elevated temperature erosion resistance of IN30ALcoatings.