Mo Addition Research Articles

Influence of Mo addition on microstructure and mechanical properties of Ti(C,N)-based cermets fabricated by in-situ carbothermal reduction of TiO2

Series of Ti(C,N)-based cermets, with various amounts of Mo, are fabricated by in-situ carbothermal reduction of TiO2. SEM, TEM, XRD and EDS analysis are utilized to analyze the phase composition and microstructure of as-prepared cermets. The results reveal that the volume percentage of white-core grains in as-prepared cermets significantly larger than that in cermets fabricated by traditional methods. In addition, there are two types of white core/gray rim grains. One is the grains with bright white cores and the other is grains with offwhite cores. Mo plays an important role in the formation of rims and white cores. With increasing Mo addition, the rims of grains with white core tend to be complete and the rims of grains with black core become thinner. The volume percentage of grains with white core significantly increases due to the diffusion of Mo during solid-state sintering. Moreover, the dislocation formed in rim phase adjusts the misfit of rim/binder interface. As a result, the semi-coherent interface is observed in rim/binder interface of grains with black core. Overall, the cermet, with Mo content of 14 wt %, renders optimal mechanical properties, with fracture toughness (KIC) of 11.2 MPa m1/2, transverse rupture strength (TRS) of 2403 MPa and a hardness of 90.8 HRA.

Facile fabrication of amorphous NiMo catalysts for alkaline hydrogen oxidation reaction

The performance of HOR was improved due to the synergistic effect of alloying of Ni with Mo and the enhanced bifunctional effect through repeated potential cycling. • Binary Ni-Mo catalysts with various compositions are prepared via electrodeposition. • Prepared Ni-Mo catalysts are evaluated for HOR activity in alkaline media. • Ni 62 Mo 38 shows excellent catalytic activity and durability after repeated cycles. • This is attributed to the structural advantages and modified electronic structure. Abstract 1 1 Hydrogen oxidation reaction (HOR), anion exchange membrane fuel cell (AEMFC), proton exchange membrane fuel cell (PEMFC), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), KetjenBlack (KB), glassy carbon (GC), reversible hydrogen electrode (RHE), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). For the anion exchange membrane fuel cell (AEMFC), the development of non-precious hydrogen oxidation reaction (HOR) catalysts is crucial for overcoming cost-related limitations in commercialization. Among the non-precious HOR catalysts, NiMo catalysts with various compositions are studied. The composition of Mo is explored up to 45 % through the fast and facile electrodeposition technique. The prepared Ni x Mo 100-x catalysts have similar particle sizes and shapes, as well as amorphous structures owing to the adsorption of the citrate and Mo addition. Among the Ni x Mo 100-x catalysts, Ni 62 Mo 38 shows the highest HOR activity of 0.94 and 1.31 mA/cm 2 at 0.05 and 0.10 V RHE , respectively, in 0.1 M KOH solution. Additionally, the catalyst shows improved performance after the stability test (a maximum of 2.39 mA/cm 2 after 100 cycles and 2.02 mA/cm 2 after 3000 cycles at 0.10 V RHE , which are 111 % and 93.5 % of the initial performance of Pt/C, respectively), compared to its initial activity. This is superior to those of previously reported non-precious HOR catalysts, indicating its applicability to the AEMFC. This improved performance is attributed to the structural properties (amorphous and large electrochemical surface area), modified electronic structure of Ni by alloying with Mo, and strengthened bifunctional effect by repeated potential cycling.

Effects of Nb and Mo additions on thermal behavior, microstructure and magnetic property of FeCoZrBGe alloy* *Project supported by the National Natural Science Foundation of China (Grant No. 51301075) and supported by Sinoma Institute of Materials Research (Guang Zhou) Co., Ltd.

Both Nb and Mo additions play a vital role in FeCo-based alloys and it is crucial to understand their roles and contents on thermal behavior, microstructural feature and magnetic property of alloys. Nanocrystalline alloy ribbons Fe40Co40Zr9 – y M y B10Ge1 (y = 0–4; M = Nb, Mo) were prepared by crystallizing the as-quenched amorphous alloys. The effects of Nb and Mo additions on structures and properties of the Fe40Co40Zr9B10Ge1 alloy are investigated systemically and compared. With increasing Nb or Mo content, the primary crystallization temperature, grain size of α-Fe(Co) phase and coercivity H c all decrease. Moreover, the effect of Mo addition on thermal behavior, microstructure and magnetic properties of the FeCoZrBGe alloy is greater compared to Nb addition. The gap between primary and secondary crystallization peaks of Mo-containing alloys is wider than that of Nb-containing alloys. Both grain size and H c of Mo-containing alloys are smaller than those of Nb-containing alloys. For Fe40Co40Zr9B10Ge1 alloy, high Mo addition proportion is better compared to high Nb addition proportion.

A remarkable Mo doped Ru catalyst for hydrogen generation from sodium borohydride: the effect of Mo addition and estimation of kinetic parameters

At present, carbon nanotube supported monometallic Ru at 3 wt% Ru loading (3% Ru/CNT) per gram support and bimetallic RuMo at 3 wt% Ru loading per gram support (3% Ru-Mo/CNT) at varying Ru:Mo atomic ratios are synthesized via sodium borohydride (NaBH4) reduction method to investigate their performance towards NaBH4 hydrolysis. These monometallic Ru/CNT and bimetallic Ru:Mo/CNT catalysts prepared at varying Ru:Mo atomic ratios are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy-energy dispersive X-ray analysis (SEM–EDX), and transmission electron microscopy (TEM). Characterization results reveal that Mo addition to Ru alters the electronic state of the catalysts. The NaOH concentration, the amount of catalyst, the NaBH4 concentration and the temperature parameters that affect the hydrolysis rate of this synthesized and developed catalyst were examined. The kinetic calculations of these parameters related to the order of the reaction were determined. Under optimum conditions catalyst hydrogen production rate was found to be 82,758.43 ml H2 g−1cat min−1. The reaction order (n) and activation energy (Ea) are determined as 0.42 and 35.11 kJ mol−1. Ru:Mo/CNT catalyst is a novel and promising catalyst for hydrogen generation from NaBH4.

Evaluation of Mechanical Properties and Microstructures of Direct‐Quenched and Direct‐Quenched and Tempered Microalloyed Ultrahigh‐Strength Steels

Herein the effects of molybdenum and niobium on the microstructures and mechanical properties of laboratory‐rolled and direct‐quenched and direct‐quenched and tempered steels are revealed. The microstructures are martensitic with yield strength of 766–1119 MPa in direct‐quenched condition and 632–1011 MPa in direct‐quenched and tempered condition. Mo and Nb additions lead to a fine martensitic microstructure that imparts a good combination of strength and toughness. Steel with 0.5 wt% molybdenum has a high yield strength of 1119 MPa combined with low 28 J transition temperature of −95 °C in direct‐quenched condition. Molybdenum and niobium increase the strength significantly during tempering due to enhanced solute drag and precipitation hardening. Addition of 0.25 wt% molybdenum increases yield strength from 632 to 813 MPa after tempering. However, the combination of niobium and molybdenum results in even greater increase in yield strength during tempering compared to the nonalloyed version, producing almost 400 MPa increase in yield strength. Transmission electron microscopy reveals that only niobium forms stable precipitates during tempering, indicating that molybdenum largely remains in solution. X‐ray diffraction analysis elucidates that molybdenum and molybdenum–niobium alloying prevents annihilation of dislocations, leading to the presence of high densities of dislocations after tempering.

Bioactive Compounds and Antioxidant Capacity of Moringa Leaves Grown in Spain Versus 28 Leaves Commonly Consumed in Pre-Packaged Salads

Total antioxidant capacity (TAC) evaluated by ferric ion reducing antioxidant power (FRAP) assay, ABTS, DPPH, and Oxygen radical absorbance capacity (ORAC) assay, and total polyphenol content (TPC) by Folin–Ciocalteu were determined in Moringa oleifera leaves (MO) grown in Spain, and compared with 28 different vegetable leaves pre-packaged for consumption as a salad. Total carotenoids, flavonoids, and chlorophylls were also determined in the samples with highest TAC. Two different extraction procedures were applied to obtain the methanolic fraction and the lipophilic and hydrophilic fractions. The highest TAC and TPC contents were found in MO. High values were also found in red chicory, “lollo rosso”, and oak lettuce. The lowest TAC and TPC values were obtained in iceberg lettuce. The correlations between the extraction procedures and methods assayed were high and statistically significant. In the light of these results, we suggest the addition of MO to the existing range of fresh-cut salad foods would increase their antioxidant content by up to six times.

Mechanical performance of simple cubic architected titanium alloys fabricated via selective laser melting

Simple cubic architected titanium alloys with 72.7% porosity were additively manufactured via selective laser melting (SLM). Their mechanical performance was closely related to the alloy composition that was controlled through in-situ alloying of Ti-6Al-4V with Mo (β stabilizing element). Experimental results showed that addition of Mo into the Ti-6Al-4V alloy effectively suppressed the formation of αʹ martensite and increased the fraction of β phase in the as-SLMed simple cubic structure. At 15 wt.% Mo addition, the martensitic transformation was completely suppressed and full metastable β phase was obtained in the alloy. As a result, the first compressive fracture strain of the SLMed architected alloy increased from 2.82% (without Mo addition) to 7.24%, the elastic modulus decreased from 12.6 ± 3.3 GPa to 6.7 ± 0.6 GPa, and yield strength to elastic modulus ratio was accordingly increased from 12.9 × 10−3 to 18.6 × 10−3. In addition, the architected simple cubic structure also demonstrated a controllable plateau stress and high energy-absorbing capacity. As Mo addition increased from 0 wt.% to 15 wt.%, the cumulative energy absorption to the densification strain significantly increased from 31.9 mJ m−3 to 47.7 mJ m−3. Hence, the simple cubic architected titanium alloys will have strong potential to be used to fabricate vibration damping devices and biomedical implants.

Improvement of mechanical properties in micro-alloying Al-Si-Mg-Zn cast alloy

The strengthening effects of micro Mo, Zr, La and Ce addition and short-time artificial aging (STAA) on mechanical properties of high pressure die-casting (HPDC) Al-Si-Mg-Zn alloy were investigated. The additions of Mo, Zr, La and Ce induced the formation of nanoscale phases in rapid solidification of HPDC. After the STAA, the supersaturated α-Al matrix solidified rapidly resulted in the fast and adequate precipitation of nano β'-Mg2Si phases. The combination of nano-phases containing the micro elements and nano β'-Mg2Si precipitates improved hardness and yield strength of the Al-Si-Mg-Zn cast alloy.

Microstructure, Tensile Flow and Work Hardening Behavior of W–Ni–Fe Alloys: Effect of Co and Co + Mo Additions

Present work describes the effect of additions of Co and Co + Mo in ternary (W–Ni–Fe) tungsten heavy alloys (WHAs) on the microstructures, mechanical properties, tensile flow and work hardening behavior. In present work, four ternary with different Ni/Fe ratios, one quaternary (containing Co) and one quinary (containing Co + Mo) WHAs based on 92 wt.% W have been investigated. Additions of Co and Co + Mo result in a slight decrease in W-grain size and volume fraction of matrix phase and increase in contiguity for a given Ni/Fe ratio. This has resulted in an increase of σYS and σUTS values which are attributed to higher W solubility in the matrix phase in both the heat treated as well as swaged conditions. On the other hand, the Co and Co + Mo containing alloys exhibit decrease in elongation and impact toughness values due to increase in W–W contiguity as well as decrease in the matrix volume fraction in both the heat treated and swaged conditions. Bulk and micro-hardness values of W-grains and matrix phase have enhanced in Co and Co + Mo containing alloys in swaged condition as a result of substantial solid solution strengthening of matrix phase. True stress–true plastic strain curves of present alloys exhibit single slope on log–log scale in swaged condition. The instantaneous work hardening curves reveal the presence of three distinctive regimes (I, II and III). The second derivatives of true stress–true plastic strain curves are parabola.

Investigating the Influence of Cr and Mo Additions to Commercial Ni-Based Alloys Exposed to Neutral and Acidic Chloride Solutions

The corrosion behaviour of four commercially available Ni-based alloys is presented for both natural and potential-controlled corrosion in chloride solutions. Electrochemical evidence suggests a balance of Cr and Mo is essential to maintaining passive film stability in chloride solutions, especially those in which acidic conditions may develop. In near-neutral solutions, increased Cr content results in lower corrosion rates and improved passive properties; however, an increase in Cr content above 15 wt.% provided only minor additional benefits. In acidic solutions, Mo content is essential to corrosion resistance and imparts two major benefits: increased film stability and rapid repassivation of breakdown events. Since localized corrosion and the critical chemistry which accompanies these processes are of concern in many chloride-containing applications, a delicate balance of Cr and Mo must be considered; although optimal concentrations have yet to be determined.

Trace Metal Availability Affects Greenhouse Gas Emissions and Microbial Functional Group Abundance in Freshwater Wetland Sediments.

We investigated the effects of trace metal additions on microbial nitrogen (N) and carbon (C) cycling using freshwater wetland sediment microcosms amended with micromolar concentrations of copper (Cu), molybdenum (Mo), iron (Fe), and all combinations thereof. In addition to monitoring inorganic N transformations (NO3–, NO2–, N2O, NH4+) and carbon mineralization (CO2, CH4), we tracked changes in functional gene abundance associated with denitrification (nirS, nirK, nosZ), dissimilatory nitrate reduction to ammonium (DNRA; nrfA), and methanogenesis (mcrA). With regards to N cycling, greater availability of Cu led to more complete denitrification (i.e., less N2O accumulation) and a higher abundance of the nirK and nosZ genes, which encode for Cu-dependent reductases. In contrast, we found sparse biochemical evidence of DNRA activity and no consistent effect of the trace metal additions on nrfA gene abundance. With regards to C mineralization, CO2 production was unaffected, but the amendments stimulated net CH4 production and Mo additions led to increased mcrA gene abundance. These findings demonstrate that trace metal effects on sediment microbial physiology can impact community-level function. We observed direct and indirect effects on both N and C biogeochemistry that resulted in increased production of greenhouse gasses, which may have been mediated through the documented changes in microbial community composition and shifts in functional group abundance. Overall, this work supports a more nuanced consideration of metal effects on environmental microbial communities that recognizes the key role that metal limitation plays in microbial physiology.

Influence of porosity and alloy addition on the wear behaviour of sinter-forged C45 steel using Taguchi method

Elemental powders of iron (Fe), molybdenum (Mo), and carbon (C) were mixed in a pot mill to obtain the compositions of C45, C45–1% Mo, and C45–2% Mo steels. They were then compacted and sintered. The sintered preforms had a density of 75% of the theoretical density (TD). Then, the sintered preforms were subjected to densification to obtain the two densities of 80% and 85% TD through forging. The sintered and densified preforms of the alloy steel were subsequently machined to obtain the required wear test specimens. The experiments were conducted on a pin-on-disc tribometer, conforming to ASTM G99 standards, on a rotating EN32 disc. Using Minitab 16 software, dry sliding wear experiments were planned using a L27 orthogonal array. The percentage TD of the specimens (%Theoretical density + %Porosity = 1), percentage Mo addition, load, and sliding velocity were taken as input parameters, and mass loss was the output parameter. It was observed that increasing the density of the alloy steel adversely affects the wear resistance of the alloy steel, and thus the mass loss is increased. The addition of Mo to the C45 steel improves the wear resistance irrespective of density, owing to hard-phase carbides present in the microstructure. Empirical correlations for mass loss with respect to input parameters were developed using regression analysis. The hardness of the alloy steel was directly related to the density of the alloy. Mo addition contributed to an increase in hardness of the alloy steel. It was observed from optical images of the wear pattern that the C45 steel is subjected to uniform wear, as an evenly spread wear track appeared in the images. On the other hand, it was observed that the C45–Mo-alloyed steel exhibited non-uniform wear because of hard-phases present in the microstructure.

The Influence of Mo Additions on the Microstructure and Mechanical Properties of AlCrFe2Ni2 Medium Entropy Alloys

The alloy system Al-Cr-Fe-Ni provides means for developing novel duplex materials composed of face-centered cubic (FCC) and body-centered cubic (BCC) phases with nearly equal volume fraction. We performed an alloy development study starting from the medium entropy alloy AlCrFe2Ni2 and adding small amounts of molybdenum in the following series (at.%): Al17Cr17Fe33Ni33, Al17Cr17Fe33Ni33Mo1, Al16Cr16Fe33Ni33Mo2, Al16Cr16Fe33Ni33Mo3. We focused the research on samples with an ultrafine vermicular duplex microstructure, a unique structure requiring sufficiently high cooling rates to suppress the conventional Widmanstatten colony formation. The samples were produced by arc melting in buttons of 300 g each. We characterized the microstructure of the samples using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD). The EBSD results revealed significant strain in the FCC phase, which is characteristic for the ultrafine vermicular duplex microstructure and its specific formation pathway. We investigated mechanical properties of the samples by micro-indentation and 3-point bending in a miniature testing device. The test specimens were in the as-cast condition, as well as in distinct annealed conditions. Annealing treatments were carried out at 950 °C and 1100 °C under argon. The annealing lasted from 10 minutes to 6 hours, followed by water quenching. Prolonged annealing at 950 °C of Mo-containing samples resulted in the formation of sigma-phase. Annealing at 1100 °C safely avoided sigma-phase formation, while leading to a good balance between the flexural strength and ductility of these samples. Mechanical testing also included the well-established superduplex steel 1.4517 (DIN EN 10283 / ASTM A890) as reference material.

Effects of Mo-doping on the microstructure and mechanical properties of CoCrNi medium entropy alloy

Abstract

Individual and synergistic effects of Mn and Mo micro-additions on precipitation and strengthening of a dilute Al–Zr-Sc-Er-Si alloy

Dilute Al–Er-Sc-Zr-Si alloys strengthened by coherent Al3(Er,Sc,Zr)(L12) nanoprecipitates have excellent coarsening- and creep-resistance up to 400 °C. Herein, the effects of micro-additions of 0.25 at.% Mn and/or 0.10 at.% Mo to a dilute Al-0.08Zr-0.014Sc-0.008Er-0.09Si (at.%) alloy are investigated with respect to precipitate evolution and the resulting strengths after different aging treatments. Both Mn and Mo provide solid-solution strengthening, contributing to ambient-temperature strength, in addition to elevated-temperature creep resistance. L12-core-shell nanoprecipitates created upon aging at 400 °C exhibit Mn partitioning at the Sc- and Er-rich precipitate cores, and Mo throughout the precipitates. Manganese-modified L12-precipitates exhibit a higher number density (~7.5 × 1022 m−3 for peak-aged condition), while Mo-modified L12-nanoprecipitates display significantly improved coarsening-resistance. No notable synergistic effect of Mn and Mo additions strengthening upon isothermal aging at 400 °C are observed. Isochronal aging displays, however, that a Mo addition delays the formation of Al/Si/Mn-rich α-precipitates from 425 °C to 475 °C. Both Mn and Mo additions improve the creep resistance of the alloys at 300 °C. Manganese-bearing alloys exhibit a more significant effect, as it doubles the threshold stress compared to the Mn-free base alloy. This strong effect could be a result of fine α-precipitates (<20 nm) formed during the creep experiments at 300 °C for the peak-aged sample. The over-aged Mn-containing samples are less creep resistant due to coarsening of both existing L12-nanoprecipitates and the absence of fine α-precipitates formed during creep.

The Effect of Simultaneous Si and Ti/Mo Alloying on High-Temperature Strength of Fe3Al-Based Iron Aluminides.

The effect of phase composition and morphology on high-temperature strength in the compression of Fe-Al-Si-based iron aluminides manufactured by casting was investigated. The structure and high-temperature strength in the compression of three alloys—Fe28Al5Si, Fe28Al5Si2Mo, and Fe28Al5Si2Ti—were studied. Long-term (at 800 °C for 100 h) annealing was performed for the achievement of structural stability. The phase composition and grain size of alloys were primarily described by means of scanning electron microscopy equipped with energy dispersive analysis and Electron Backscatter Diffraction (EBSD). The phase composition was verified by X-ray diffraction (XRD) analysis. The effect of Mo and Ti addition as well as the effect of long-term annealing on high-temperature yield stress in compression were investigated. Both additives—Mo and Ti—affected the yield stress values positively. Long-term annealing of Fe28Al5Si-X iron aluminide alloyed with Mo and Ti deteriorates yield stress values slightly due to grain coarsening.

Characterization and corrosion behavior of electroless Ni-Mo-P/Ni-P composite coating in CO2/H2S/Cl− brine: Effects of Mo addition and heat treatment

The electroless Ni-Mo-P/Ni-P composite coating was applied on N80 carbon steel, and the effects of Mo addition and heat treatment on the corrosion resistance enhancement in CO2/H2S/Cl− brine were studied by electrochemical measurements and surface analysis techniques. The Mo addition in the as-deposited Ni-P coating causes the microstructural transformation from amorphous to crystalline due to the reduced P content, thereby suffering severe corrosion. The impaired corrosion performance of as-deposited Mo-incorporated coating is also originated from the absence of the oxide film on the coating surface. Nonetheless, the heat-treated Ni-Mo-P/Ni-P coating exhibits desirable corrosion resistance, which is reflected by the outstanding corrosion inhibition efficiency (η = 96.1%). Heat treatment facilitates the formation of Ni4Mo phase and more importantly, the growth of an oxide film consisting of nickel and molybdenum oxides (H2S-immuned MoO3) with better passivation properties, which accounts for the remarkable corrosion resistance improvement.

Efficient hydrogenation of CO2-derived ethylene carbonate to methanol and ethylene glycol over Mo-doped Cu/SiO2 catalyst

Hydrogenation of ethylene carbonate (EC) to methanol and ethylene glycol is an attractive method for indirect hydrogenation of CO2 to methanol. Copper-based catalysts have been studied in EC hydrogenation because of their good selective activation ability for carbon-oxygen bonds. Herein, a series of Mo-doped Cu/SiO2 catalysts were prepared and used for EC hydrogenation. The catalyst with 0.5 wt% Mo dopant exhibited the highest catalytic performance of 80.9 % MeOH yield and 98.6 % EG yield with an excellent stability for at least 140 h. Detailed characterizations revealed that a proper amount of Mo addition could be beneficial to enhancing the copper dispersion and preventing them from aggregation. Moreover, it is demonstrated that the amount of surface Cu+ species was increased with some electron-deficient ones generated resulting from the strong interaction between copper and molybdenum species, which may effectively promote the activation of EC. The optimal 0.5 wt% Mo-doped catalyst showed remarkably enhanced efficiency and the apparent activation energy barrier of 115.8 kJ mol−1 is much lower than that of the Mo-free sample in EC hydrogenation. The insights may bring new possibilities to further design efficient copper-based catalysts for the hydrogenation of carbon-oxygen bonds.

Microstructure, magnetic and mechanical properties of Fe–28Cr–15Co–1Si cast magnets containing Mo and Ti additives

In this study, the development of Fe–28Cr–15Co–1Si–xM, M = Ti and Mo, x = 1, 2, 3 (wt.%) cast permanent magnets by a thermomagnetic treatment was investigated. The alloys were melted in a vacuum induction furnace (VIM) using pure raw materials and then cast in alumina tubes. Structural, mechanical, and magnetic properties of the alloys were evaluated at different stages of heat treatment. Specimens in the solution annealed condition, showed a coarse grain with a body-centered cubic (BCC) structure (α phase), which decomposes into two α1 and α2 phases by a spinodal transformation during the thermomagnetic treatment. By addition of Mo to Fe–28Cr–15Co–1Si alloy, the strain energy of decomposition increases by concentrating in the α2 phase. This results in a difference in the lattice parameter between α1 and α2 phases and an improvement in the magnetic properties of the alloy. The presence of Ti in the alloys raised the amount of α1 phase, which eventuates in the suppression of the unwanted σ or γ phases in the annealed state. Ti and Mo additions also affect the development of shape anisotropy in the ferromagnetic α1 particles, which in turn improves the magnetic properties of the alloys. The best magnetic properties turn out to be in Fe–28Cr–15Co–1Si–3Mo, and Fe–28Cr–15Co–1Si–2 Ti alloys: Br = 0.98 T (9.8 kg), Hc = 67.66 kA/m (0.85 kOe) and (BH)max = 41.27 kJ/m3 (5.2 MGOe), and Br = 0.93 T (9.3 kg), Hc = 65.27 kA/m (0.82 kOe) and (BH)max = 38.09 kJ/m3 (4.8 MGOe), respectively. The hardness test results verified that in the Fe–Cr–Co-based alloys with spinodally decomposed structure, the internal stresses are more effectual than composition gradients on the alloy’s strength.

Sintering behavior and alloying elements effects on the properties of CP-Titanium sintered using pulsed electric current

Mechanical properties of grade 1 commercially pure titanium (CP–Ti) are characterized by a good combination of strength and ductility at elevated temperatures. CP-Ti mechanical properties at room and elevated temperature can be enhanced by alloying with other elements to meet up with its demand for industrial applications. In this study, the effect of Al–Mo addition and sintering temperature on the densification, microstructure, and mechanical properties of spark plasma sintered CP-Ti compacts were investigated. CP-Ti and Ti–7Al–1Mo (wt.%) compacts sintering were carried out at a constant holding time of 10 min, pressure of 50 MPa and sintering temperature of 800 °C, 1000 °C, and 1100 °C under vacuum. Full densification with Vickers hardness values of 352 ± 17 H V was obtained for the developed Ti–7Al–1Mo alloy at 1000 °C. Different microstructural transformations and phase evolution were observed in the as-sintered compact with respect to sintering temperature. The role of the alloying element and sintering temperature on the relative density, microstructure, hardness, and wear of the as-sintered samples were discussed. This paper shows that alloying of CP-Ti with Al and Mo enhances its microstructure and mechanical properties.