Molybdenum Content Research Articles

INVESTIGATION OF VARIATION OF SPRAYING CONDITIONS ON VARIATION OF STRENGTH CHARACTERISTICS OF MoCrN COATINGS

Interest in thin-film protective coatings based on nitride compounds of molybdenum and chromium is due to the great prospects for their use as wear-resistant anti-corrosion coatings with high resistance to both external effects in the form of mechanical friction, pressure, and corrosion processes, when exposed to aggressive media, hydrogenation or high temperatures. However, the stability of nitride coatings are primarily determined by the conditions of their obtaining, which not least depend on the power of magnetron sputtering, the variation of which allows you to change the ratio of elements in the composition of coatings. The key objective of this research is to measure the strength characteristics measured by indentation method depending on the conditions of obtaining coatings under variation of sputtering power, as well as to establish the influence of variation of conditions of obtaining thin film coatings on the change of hardness and hardening factors. According to the presented data, changing the conditions of magnetron sputtering by varying the power leads to the formation of stronger stable coatings with high resistance to cracking under changing external load. In the course of research it was determined that changing the conditions of magnetron sputtering coatings, leading to an increase in the concentration of molybdenum in the composition of coatings leads to more than 60–80% hardening, as well as an increase in resistance to cracking under external influences.

Experimental Research on the Study of Мéntha Piperíta Makro- and Microelement Composition Growing in Goris, Syunik Region

The purpose of our work was to study the qualitative and quantitative composition of the mineral elements of peppermint (Méntha piperíta) leaves. The relevance of the study is revealed by the fact that, though some trace elements in low concentrations are necessary for plant growth, their excess can lead to plant death. This effect depends both on the nature of the element and on the type of plant. To achieve this goal, we used the method of optical emission spectroscopy with inductively coupled plasma on an Agilent 5110 ICP-OEC equipment. The object of research was the dried aerial part of peppermint (Méntha piperíta) growing in Goris region of Armenia. The content of 30 elements was determined, for five of which the biological absorption coefficient is greater than unity. This means that these elements accumulate in plants. These include strontium and molybdenum, which are toxic elements. Based on the data presented, it is certainly necessary to control the maximum permissible concentrations of molybdenum and strontium in peppermint (Méntha piperita) collections before using it in cooking and for the creation of medicinal products.

Liming improves wheat nutrient use efficiency, yield, and quality on acid soils in Ethiopia

Soil acidity is a major constraint for food production in the Highlands of Ethiopia, the main cereal growing area. We conducted two field trials in nutrient-poor, acidic fields in the Highlands of Ethiopia to evaluate the effects of dolomitic lime at rates of 0, 6 and 12 t ha−1 on the utilization of commonly used phosphorus (P) and nitrogen (N) fertilizers. Blended fertilizer (at a liming rate of 12 t ha−1), containing potassium (K), sulfur (S), zinc (Zn) and boron (B) were also evaluated. The liming rate of 12 t ha−1 improved the utilization of P fertilizer most and only 20 kg P ha−1 was needed to reach 90% of the maximum wheat yield in soils with a high P sorption capacity. Liming and P fertilization, increased the N use efficiency from 0 to 30%, whereas the P use efficiency increased from 3 to 25%. Liming also increased the concentrations of calcium (Ca), magnesium (Mg), sulfur (S), molybdenum (Mo) and Zn and retained the concentration of copper (Cu) in wheat grain at a higher level than in unlimed treatments. This indicates that even high liming rates did not depress the utilization of nutrients from fertilizers, lime or soil. Regarding harmful heavy metals, liming reduced the nickel (Ni) concentration in wheat to about half of that in unlimed treatments. This study demonstrated how liming was a prerequisite for improving the quantity and quality of wheat growing in the acidic soils of the Ethiopian Highlands.

Exposure to iodine, essential and non-essential trace element through seaweed consumption in humans

Seaweed consumption has gained popularity due to its nutritional value and potential health benefits. However, concerns regarding the bioaccumulation of several trace elements highlight the need for comprehensive studies on exposure associated with seaweed consumption. To address this gap in knowledge, we carried out a feeding intervention study of three common edible seaweeds (Nori, Kombu, and Wakame) in 11 volunteers, aiming to elucidate the extent of both beneficial and harmful trace element exposure through seaweed consumption in humans. Concentrations of total arsenic, cobalt, copper, cadmium, iodine, molybdenum, selenium, and zinc were measured in urine samples before and following seaweed consumption. Elements concentrations were also measured in the seaweeds provided for the study. Descriptive analysis for each element were conducted and we used quantile g-computation approach to assess the association between the 8-element mixture and seaweed consumption. Differences in urine element concentrations and seaweed consumption were analyzed using generalized estimating equations (GEE). Urinary concentrations of iodine and total arsenic increased after seaweed consumption. When we analyze the 8-element mixture, the largest weight was observed for iodine after Kombu consumption while for total arsenic was observed after Wakame consumption. Similar results were observed when we compared the mean differences between the elements before and after seaweed consumption through the GEE. Seaweed consumption relates with increased urinary iodine and total arsenic concentrations, particularly after Kombu and Wakame consumption.

ПАЛЕОГЕНОВЫЕ СТОЛБЧАТЫЕ СТРОМАТОЛИТЫ МЕСТОНАХОЖДЕНИЯ «КАМЫШИНСКИЕ УШИ» (НИЖНЕЕ ПОВОЛЖЬЕ)

The article discusses the results of our preliminary studies of Paleocene columnar stromatolites from the “Kamyshinskie Ushi” location, near the northwestern periphery of the town of Kamyshin. The morphology, composition and features of the buildings were studied. They can be attributed to the morphological type of columnar non-branching stromatolites; fan-shaped branching stromatolites are less common; their mineral composition differs little from the host rocks and consists mainly of quartz grains cemented by silicon oxide. Dark layers are much more saturated with ore inclusions. The concentration of chromium, molybdenum, wolfram, vanadium, cobalt and nickel in dark varieties increases noticeably, which confirms their stromatolite origin. The deposition settings of their formation remain controversial.

Effect of molybdenum concentration on mechanical, microstructural, corrosion, and tribological properties of (Al3Ni–Al3Ni2)100-x -Mox (x= 3, 5, and 7 wt%) composites

The nickel aluminide intermetallic is a crucial material for structural components in high-temperature applications. This study investigates the impact of adding Mo at three different concentrations (3, 5, and 7 wt%) to the Al3Ni–Al3Ni2 intermetallic powder produced by mechanical alloying. The composite powders are then consolidated by cold compaction and sintered at a temperature of 800 °C. The resulting Al3Ni–Al3Ni2 intermetallic, Al3Ni–Al3Ni2–Mo3, Al3Ni–Al3Ni2–Mo5, and Al3Ni–Al3Ni2–Mo7 composites are examined for their mechanical, metallurgical, corrosion, and tribological behaviors. The microstructure showed that adding 3 and 5 wt% of Mo to the Al3Ni–Al3Ni2 intermetallic resulted in good metallurgical bonding, less porosity, and grain refinement with a homogeneous distribution. However, the addition of 7 wt% Mo resulted in high porosity with an inhomogeneous distribution. The Al3Ni–Al3Ni2–Mo5 composite showed the highest yield strength (947 MPa), ultimate tensile strength (1365 MPa), and hardness (420.4 HV) due to the dispersion-strengthening effect and grain refinement. On the other hand, the Al3Ni–Al3Ni2–Mo7 composite exhibited lower values than the Al3Ni–Al3Ni2–Mo3 and Al3Ni–Al3Ni2–Mo5 composites due to the inhomogeneous distribution of the Mo elements observed through energy dispersive X-ray spectroscopy (EDS) mapping. The presence of a passive film on the surface of the Al3Ni–Al3Ni2–Mo5 composite resulted in higher corrosion resistance and lower corrosion rate (0.0221 mm/yr) compared to other samples. The wear test results showed that the Al3Ni–Al3Ni2–Mo5 composite exhibits better wear resistance than the other samples due to tribo oxide layers.

Study of phase equilibrium of refractory high-entropy alloys using the atomic size difference concept for turbine blade applications

Abstract In the pursuit of advancing turbine blade materials, refractory high-entropy alloys (RHEAs) have emerged as promising candidates, offering superior performance at elevated temperatures compared to conventional superalloys. With the plateauing of melting temperatures in Ni-based superalloys, the demand for innovative material systems capable of substantial performance enhancements in turbines has increased. The expansive compositional space of high-entropy alloys (HEAs) presents a rich yet underexplored realm, particularly concerning the intricate phase equilibria pivotal for alloy stability at high temperatures. This research purpose is to elucidate the phase formation dynamics within the W–Re–Ni–Co–Mo HEA system across varying atomic percentages of each constituent element. Employing two-dimensional mapping methodology for correlating atomic size difference and enthalpy mix parameters, enabling the differentiation between intermetallic (IM) phase and single-phase formations in the non-equimolar W–Re–Ni–Co–Mo system across numerous atomic percentages of each element. Major findings indicate distinct phase formations based on elemental compositions, with elevated nickel and rhenium percentages favouring single-phase solid solution (SPSS) structures, while diminished concentrations yield alternative configurations such as (IM + SPSS). Similarly, variations in tungsten and molybdenum concentrations influence phase stability. The ability to assess phases for diverse atomic percentages of elements in the W–Re–Ni–Co–Mo system will facilitate to analyse HEA systems for high-temperature turbine blades.

Higher Concentrations of Essential Trace Elements in Women Undergoing IVF May Be Associated with Poor Reproductive Outcomes Following Single Euploid Embryo Transfer.

Essential trace elements are micronutrients whose deficiency has been associated with altered fertility and/or adverse pregnancy outcomes, while surplus may be toxic. The concentrations of eight essential trace elements were measured using inductively coupled mass spectrometry (ICP-MS) and assessed with respect to clinical in vitro fertilization (IVF) outcomes in a population of 51 women undergoing IVF with intracytoplasmic sperm injection (ICSI), pre-implantation genetic screening for aneuploidy (PGT-A), and single frozen euploid embryo transfer (SET/FET). Specifically, copper (Cu), zinc (Zn), molybdenum, selenium, lithium, iron, chromium, and manganese were quantified in follicular fluid and whole blood collected the day of vaginal oocyte retrieval (VOR) and in urine collected the day of VOR and embryo transfer. We found that the whole blood Cu/Zn ratio was significantly associated with superior responses to ovarian stimulation. Conversely, the whole blood zinc and selenium concentrations were significantly associated with poor ovarian response outcomes. Higher levels of whole blood zinc and selenium, urinary selenium, lithium, and iron had significant negative associations with embryologic outcomes following IVF. Regarding clinical IVF outcomes, higher urinary molybdenum concentrations the day of VOR were associated with significantly lower odds of implantation and live birth, while higher urinary Cu/Mo ratios on the day of VOR were associated with significantly higher odds of implantation, clinical pregnancy, and live birth. Our results suggest that essential trace element levels may directly influence the IVF outcomes of Spanish patients, with selenium and molybdenum exerting negative effects and copper-related ratios exerting positive effects. Additional studies are warranted to confirm these relationships in other human populations.

Molybdenum-Doped ZnO Thin Films Obtained by Spray Pyrolysis.

A batch of ZnO thin films, pure and doped with molybdenum (up to 2 mol %), were prepared using the spray pyrolysis technique on glass and silicon substrates. The effect of molybdenum concentration on the morphology, structure and optical properties of the films was investigated. X-ray diffraction (XRD) results show a wurtzite polycrystalline crystal structure. The average crystallite size increases from 30 to 80 nm with increasing molybdenum content. Scanning electron microscopy (SEM) images demonstrate a smooth and homogeneous surface with densely spaced nanocrystalline grains. The number of nuclei increases, growing over the entire surface of the substrate with uniform grains, when the molybdenum concentration is increased to 2 mol %. The estimated root mean square (RMS) roughness values for the undoped and doped with 1 mol % and 2 mol % of ZnO thin films, defined by atomic force microscopy (AFM), are 6.12, 23.54 and 23.83 nm, respectively. The increase in Mo concentration contributes to the increase in film transmittance.

Mechanism for Control of Laser‐Induced Stainless Steel Oxidation

AbstractThis paper presents the development of a model for Nd:YAG laser surface oxidation of 316L stainless steel. A full factorial design of experiments (DOE) are implemented to produce a model for the prediction of elemental composition and color. The elemental composition of the films produced where measured using an X‐ray photoelectron spectroscopic (XPS) and the color is measured using optical reflectance spectroscopy. Oxide layers produced have a Cr/Fe ratio in the range of 0.13–2.09, and highly controllable color variation via single‐pass laser process. The effect of the process parameters used such as power, frequency, and scan speed on laser‐induced oxides is examined with an aim to produce a model suitable for predictive control of the elemental composition and color of the oxide film. Surface morphology control via alteration of the laser power is an important factor for defining the resulting coloration. A new finding from this work is the discovery that within the range of laser surface processing parameters investigated, the molybdenum concentration is inversely proportional to the chromium concentration. This paper provides data required for control of 316L‐SS surface chemistry, and for the expansion of the current thermokinetic model to incorporate the mechanistic effect of molybdenum.

Dynamics of molybdenum and barium in the Bay of Brest (France) explained by phytoplankton community structure and aggregation events

Primary producers are essential organisms for marine ecosystems because they form the basis of food webs, produce half of atmospheric oxygen and are involved in various biogeochemical cycles. At the end of a bloom event, phytoplankton cells are known to produce organic compounds that act as a ‘cement’, allowing the cells to stick together and form large sinking structures called aggregates. These aggregates are microenvironments with chemical properties that are very different from the surrounding water. The main objective of this study was to determine how the temporal variations in cell assemblages over time and the formation of aggregates following a bloom affect the concentrations of molybdenum (Mo) and barium (Ba) in the water column, which are elements typically measured within accretionary hard tissues (e.g., mollusc shells) to track phytoplankton dynamics in the environment. To do so, we performed an environmental monitoring from March to October 2021 at Lanvéoc in the Bay of Brest (France) during which several biological (e.g., variations in phytoplankton assemblages) and chemical (e.g., chemical properties of the water column) parameters were measured once to twice per week. Our results show that spring and summer blooms of Gymnodinium, known to be enriched in Mo, could be one of the reasons explaining the particulate Mo enrichments in the water column. In addition, large phytoplankton aggregates transported a significant amount of Mo to the seafloor and associated suspension feeders. In contrast, the temporal variations in dissolved and particulate Ba concentration were strongly influenced by the formation of diatom blooms. Interestingly, there was a significant shift in Ba from the dissolved to the particulate fraction during the largest diatom bloom in late spring, associated with a significant Ba transport to the seafloor, which may be explained by the adsorption of this element onto diatom frustules. This study therefore highlights the impacts of phytoplankton on the dynamics of these elements in coastal ecosystems.

Nutritional and bioactive properties and antioxidant potential of Amaranthus tricolor, A. lividus, A viridis, and A. spinosus leafy vegetables

Climate change results in continuous warming of the planet, threatening sustainable crop production around the world. Amaranth is an abiotic stress-tolerant, climate-resilient, C4 leafy orphan vegetable that has grown rapidly with great divergence and potential usage. The C4 photosynthesis allows amaranth to be grown as a sustainable future food crop across the world. Most amaranth species grow as weeds in many parts of the world, however, a few amaranth species can be also found in cultivated form. Weed species can be used as a folk medicine to relieve pain or reduce fever thanks to their antipyretic and analgesic properties. In this study, nutritional value, bioactive pigments, bioactive compounds content, and radical scavenging potential (RSP) of four weedy and cultivated (WC) amaranth species were evaluated. The highest dry matter, carbohydrate content, ash, content of iron, copper, sodium, boron, molybdenum, zinc, β-carotene and carotenoids, vitamin C, total polyphenols (TP), RSP (DPPH), and RSP (ABTS+) was determined in Amaranthus viridis (AV). On the other hand, A. spinosus (AS) was found to have the highest content of protein, fat, dietary fiber, manganese, molybdenum, and total flavonoids (TF). In A. tricolor (AT) species the highest total chlorophyll, chlorophyll a and b, betaxanthin, betacyanin, and betalain content was determined. A. lividus (AL) was evaluated as the highest source of energy. AV and AT accessions are underutilized but promising vegetables due to their bioactive phytochemicals and antioxidants.

Valorization of biomass bottom ash in alkali-activated GGBFS-fly ash: Impact of biomass bottom ash characteristic, silicate modulus and aluminum-anodizing waste

Growing production of green energy from biomass has led to a surge in biomass bottom ash (BBA) generation, often relegated to landfills due to high leachable heavy metal content. This study proposed solidifying BBA in alkali-activated granulated ground blast furnace slag (GGBFS) and class F fly ash (CFA) blended binders. Investigations into the influence of BBA content, fineness, silicate modulus of activators, and aluminum-anodizing waste (AAW) on solidification performance were conducted, focusing on reaction mechanisms, phase assemblages, mechanical properties and leaching behavior. Results indicate relatively low reactivity of BBA and high leachable chloride (Cl-), sulphate (SO42-), chromium (Cr), molybdenum (Mo), lead (Pb) and zinc (Zn) contents from BBA. Increased BBA substitution leads to strength deterioration, while ground biomass bottom ash (GBBA) improves the mechanical performance slightly. This improvement is attributed to the increased reactive aluminosilicate content and an enhanced packing system resulting from finer particles. However, GBBA induces an increased heavy metals leaching. Higher silicate modulus activators enhance mechanical properties and reduce the leaching of Mo and Cl-, while lower silicate modulus activator accelerates the reaction process, promoting the formation of hydrotalcite-like phases and reducing the leaching of Cr and SO42-. Incorporating 0.5 wt% aluminum-anodizing waste improves immobilization efficiency of toxic ions, but further increases in dosage lead to higher leaching due to weakened mechanical performance. Overall, hybrid binders with 10 wt% G/BBA exhibit desirable mechanical properties, along with sufficient immobilization of leachable heavy metals, enabling their use as potential construction materials.

Distribution of urinary trace element exposure and dietary sources in women over 50 in an agricultural region- A community-based KoGES cohort study

BackgroundThere is a noticeable lack of information on the levels of both non-essential and essential trace elements in women aged over 50. The main objective of this study is to investigate trace element concentrations and explore the influence of sociodemographic factors and dietary sources of exposure in this demographic. MethodsWe analyzed 19 trace elements, including manganese, cobalt, copper, zinc, molybdenum, chromium, nickel, arsenic, strontium, cadmium, tin, antimony, cesium, barium, tungsten, mercury, thallium, lead, and uranium, using ICP-MS and mercury analyzer. Urine samples were obtained from a cohort of 851 women aged over 50 who participated in the 8th KoGES-Ansung study (2017–2018). Multiple linear models were employed to explore associations between urinary trace element concentrations and sociodemographic factors and dietary sources of exposure. We used K-means clustering to discern patterns of exposure to trace elements and identify contributing factors and sources. ResultsOur findings indicate higher concentrations of molybdenum (Mo), arsenic (As), cadmium (Cd), and lead (Pb) in our study population compared to women in previous studies. The study population were clustered into two distinct groups, characterized by lower or higher urinary concentrations. Significant correlations between age and urinary concentrations were observed in Ni. Smoking exhibited positive associations with urinary Cd and As. Associations with dietary sources of trace elements were more distinct in women in the high-exposure group. Urinary antimony (Sb) was positively linked to mushroom and egg intake, As to mushroom and fish, and Hg to egg, dairy products, fish, seaweed, and shellfish. ConclusionsOur study underscores the significant gap in understanding urinary concentrations of trace elements in women aged over 50. With higher concentrations of certain elements compared to previous studies and significant correlations between age, smoking, and specific food sources, it is imperative to address this gap through targeted dietary source-specific risk management.

Plant-soil relations of selenium, molybdenum and vanadium in the Richmond District of Central Queensland, Australia

Abstract Background and aims The Richmond District of Queensland (Australia) hosts seleniferous soils and is the habitat of selenium (Se) hyperaccumulator plants. These soils are also naturally enriched in vanadium (V) and molybdenum (Mo). This study aimed to survey soils and plants of the Richmond area with a focus on the Se hyperaccumulator Neptunia amplexicaulis. Methods Field collection of plant specimens and soils from the seleniferous outcrops of the Richmond District (including the Julia Creek area) was undertaken and the samples were analyzed for Se, V, Mo and other elements. Results The results show that three modes of Se accumulation can be observed with most plant species having from ~10 μg Se g−1 up to 70 μg Se g−1 in shoots, some having between 75 and 250 μg Se g−1 in shoots while both N. amplexicaulis and Acacia tephrina contained 450–700 μg Se g−1 in their shoots. There was high Se accumulation in the phyllode tips of A. tephrina. Previously unrecorded populations of N. amplexicaulis were discovered near Julia Creek. Selenium concentrations in soil are lower than historically reported from similar localities (up to 23.2 mg Se kg−1). Molybdenum concentrations between 213 and 329 μg Mo g−1 occurred in the two Se hyperaccumulators N. amplexicaulis and A. tephrina, whilst Salsola australis had the highest accumulation of V (31–66 μg V g−1). Conclusions The results suggest that the Toolebuc Formation is the source of Se in the region, but temporal variability alters how much Se is bioavailable to plants. The presence of high Mo in plant tissues is linked to Se hyperaccumulation, and V accumulation appears to have little impact on plant ecology.

Influence of molybdenum incorporation on the structural, chemical, and catalytic properties of iron cobaltite and cobalt ferrite catalysts

In this study, molybdenum doped iron cobaltite and cobalt ferrite catalysts were prepared by coprecipitation, and their structural, morphological, and optical, properties were evaluated by XRD, BET, SEM, FTIR, Raman, XPS and UV–VIS techniques. Their catalytic behavior evaluated in the malic acid oxidative decarboxylation reaction underlined the importance of the incorporation of Mo into the structure of iron cobaltite and cobalt ferrite catalysts. The catalysts with the highest molybdenum content forming cobaltite and iron molybdate phases showed better activity, with cobaltite-based catalysts being more active than ferrite-based ones.

Microstructure, mechanical properties and wear resistance of TiNbCrMo[formula omitted] refractory multi-principal element alloys

The advancement of refractory multi-principal element alloys, exhibiting superior mechanical properties and wear resistance, is of paramount importance in materials engineering. This study introduces a novel series of refractory multi-principal element alloys, designated as TiNbCrMox (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0), and methodically explores the impact of varying molybdenum (Mo) content on their microstructural characteristics, phase composition, mechanical performance, and wear resistance. Empirical analyses reveal that these alloys are primarily composed of body-centered cubic (BCC) and Laves phases. The yield strength at ambient temperature is observed to span a range from 1572.8 MPa to 1902.5 MPa. Notably, the strategic addition of Mo in controlled proportions has been found to significantly enhance the hardness and ductility of the TiNbCrMox alloys. This improvement is attributed to the modification in the Laves phase concentration and the degree of lattice distortion. Moreover, the study identifies a marked increase in the hardness of the alloys, which, in conjunction with the formation of a lubricative oxide film, substantially reduces their wear rate. Specifically, the TiNbCrMo0.6 variant demonstrates a notably low wear rate, measured at 9.05 × 10−5 mm3/(N m). This investigation offers invaluable insights into the design and development of high-strength, wear-resistant metallic materials, highlighting their potential for diverse industrial applications.

Evaluation of Metal Partitioning across Humboldt Penguin (Spheniscus humboldti) Egg Components.

Humboldt Penguin (Spheniscus humboldti) population declines are attributable to several multifaceted anthropogenic impacts. At present, the exposure of Humboldt Penguins to high concentrations of heavy metals in the marine environment is a preeminent concern, due to mining along the Peruvian coast near key rookery sites. Metal and selenium concentrations were determined in eggs collected from September 2020 to April 2021 from a managed-care penguin population at the Brookfield Zoo to establish reference values for health indices conducted on wild populations. Concentrations of 16 elements, with emphasis on those found in mine efflux-arsenic, cadmium, copper, lead, mercury, selenium, and zinc-were assessed via inductively coupled plasma mass spectrometry in yolk, albumen, and eggshell. Data analyses indicate a clear delineation between egg constituents, with lipid-rich yolk displaying notably higher concentrations (μg/g) of arsenic (0.20 ± 0.064), chromium (0.086 ± 0.03), cobalt (0.01 ± 0.003), iron (238.65 ± 54.72), lead (0.32 ± 0.97), manganese (2.71 ± 0.66), molybdenum (0.57 ± 0.14), tin (3.29 ± 0.99), and zinc (64.03 ± 13.01) than other components (albumen and eggshell). These data confirm that heavy metals are partitioned differently across Humboldt Penguin egg components, which provides insight into the potential connection between embryonic nutrient source contamination and subsequent chick viability.

Solubility of iron, chromium and molybdenum in Pb-16Li

Saturation concentration of iron, chromium, and molybdenum in Pb-16Li have been measured over the temperature range 300–550 °C. The solubility of the three metals was found to be under 10 wppm. Iron and molybdenum concentrations show only a weak variation with temperature.

The effects of oxygen addition on microstructure and mechanical properties of Ti-Mo alloys for biomedical application.

The effective use of oxygen as an alloying element in Ti alloys is attractive due to the reduction of production cost and the increase in strength and hardness of the alloy. Although the oxygen addition in a Ti alloy increases strength and hardness, it may induce brittleness. An appropriate combination of alloying elements and thermomechanical treatment must be clarified for the use of oxygen as an alloying element. Ti-(0, 1.0, 2.0, 3.0)Mo-(0, 1.5, 3.0)O alloys were developed, and their microstructure and mechanical properties were examined. Ti-1Mo-3O alloy exhibited fine grains of α+β two phases having the tensile strength of 1,297MPa with 15.5% for total strain at fracture. The Ti-1Mo-3O alloy has 1.5 times the tensile strength and the same total strain as the Ti-6Al-4V ELI alloy. Ti-(1.0, 2.0, 3.0)Mo-1.5O alloys also have excellent mechanical properties, with tensile strength of about 1,050-1,150MPa and a total strain of about 20%-25%. In order to develop a high strength and moderate ductility Ti-Mo alloy using oxygen as an alloying element, the microstructure should have fine grains of α+β two phases with proper volume fraction of α and β phases and specific molybdenum concentration in β phase.