Influence Of Nd Research Articles

The Influence of Composition and Heat Treatment on the Phase Composition and Mechanical Properties of ML19 Magnesium Alloy

Samples of ML19 magnesium alloy with composition, wt %, (0.1–0.6)Zn–(0.4–1.0)Zr–(1.6–2.3)Nd–(1.4–2.2)Y have been investigated. The influence of Nd, Y, Zn, and Zr on equilibrium phase-transition temperatures and phase composition using Thermo-Calc software is established. The Scheil–Gulliver solidification model is also used. We show the significant liquidus temperature increase if the zirconium content in alloy is higher than (0.8–0.9) wt %. Thus, a higher melting temperature is required (more than 800°C). This is undesirable when melting in a steel crucible. The change in equilibrium fractions of phases at different temperatures in ML19 magnesium alloy with a minimum and maximum amount of alloying elements are calculated. Microstructures of alloys with different amounts of alloying elements in as-cast and heat-treated condition has been studied using scanning electron microscopy (SEM). We investigate the concentration profile of Nd, Y, Zn, and Zr in the dendritic cell of an as-cast alloy. The amount of neodymium and zinc on dendritic cell boundaries increased. A high concentration of yttrium is observed both in the center and on the boundaries of the dendritic cell. A high zirconium concentration is mainly observed in the center of the dendritic cells. A small amount of yttrium is also present in zirconium particles. These particles act as nucleation sites for the magnesium solid solution (Mg) during solidification. The effect of aging temperature (200 and 250°C) on the hardness of the samples after quenching was studied. Aging at 200°C provides a higher hardness. The change in the hardness of quenched samples during aging at 200°C is investigated. Maximum hardness is observed in samples aged for 16–20 h. The two-stage solution heat treatment for 2 h at 400°C and 8 h at 500°C with water quenching and aging at 200°C for 16 h is performed. This heat treatment enables us to get tensile strength 306 ± 8 MPa and yield strength 161 ± 1 MPa with elongation 8.7 ± 1.6%.

The Influence of Nd: YAG Laser Energy on Plasma Characteristics Produced on Si: Al Alloy Target in Atmosphere Pressure

The Influence of Nd: YAG Laser Energy on Plasma Characteristics Produced on Si: Al Alloy Target in Atmosphere Pressure

Effect of chlorhexidine application or Nd:YAG laser irradiation on long-term bond strength of a self-etching adhesive system to dentin

Purpose This in vitro study aimed at evaluating the influence of Nd:YAG irradiation and chlorhexidine (CHX) application on immediate and long-term bond strength of a self-etching adhesive system to dentin.

Biometric and intraocular pressure changes after Nd:YAG laser capsulotomy

Objective. We aimed to investigate the influences of Nd:YAG ( neodymium-doped yttrium aluminum garnet ) laser capsulotomy on ocular biometric parameters. Methods. In this prospective study, 117 eyes of 117 pseudophakic patients were included. Full ocular examination, the best-corrected visual acuity (BCVA), and intraocular pressure (IOP) measurements were performed before the procedure as well as one week, one month, and three months after Nd:YAG laser capsulotomy. The axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), and pupil diameter (PD) were measured by LenStar 900 optical biometry. The measurements were repeated one week, one month, and three months. Results. The BCVA improvements at preoperative, one week, and one month were statistically significant, but no significant changes in the BCVA were found at one month and three months ( p =0.345). No association was found between the capsulotomy and mean IOP changes during the follow-up period ( p =0.300). No significant changes were found in the CCT ( p =0.059). The ACD changes occurred at preoperative; the first week and the first month were statistically significant ( p <0.001). No statistically significant differences were found between the first month and the third month ( p =0.365). No significant changes in the pupil size ( p =0.200) and AL ( p =0.112) were found after Nd:YAG laser capsulotomy. Conclusions. Our study demonstrated that the BCVA parameter changed after Nd:YAG laser capsulotomy. The BCVA and ACD values follow-up period should be at least one month after Nd:YAG capsulotomy.

Super-fast preparation of Nd-filled p-type skutterudite compounds with enhanced thermoelectric properties

P-type filled skutterudite materials have been gained considerable research interest in recent years due to their promising thermoelectric power generation applications at intermediate temperature. Herein, we systematically investigated the influence of Nd filling on the thermoelectric properties of NdxFe2Co2Sb12 (x=0.4, 0.5 0.6, 0.7 and 0.8). Nd-filled skutterudites are synthesized using a simple and time-saving induction melt spinning technique followed by spark plasma sintering. The results show that Nd-filling leads to the significant reduction in the lattice thermal conductivity and enhancement of power factor over the entire temperature range. The most marked reduction in the lattice thermal conductivity is achieved with the value of 0.76W/mK for x=0.7 sample, due to strengthened phonon scattering. Meanwhile, the highest ZT=0.98 is attained at 740K for Nd0.7Fe2Co2Sb12. The rapid synthesis procedure provides an effective pathway for the fabrication of thermoelectric materials with high performance.

Synthesis of Nd-doped ZSM-5 and its application to treating slightly polluted water

Abstract In this study, ZSM-5 zeolite was synthesized using diatomaceous mud as the raw material, and then doped with different amounts of Nd2O3. The orthogonal experiments were performed to investigate the influence of Nd:Si molar ratio, zeolite dosage, contact time, solution pH and temperature on the removal of humic acid (HA). The removal of HA was comprehensively evaluated by chemical oxygen demand (COD), UV254 and UV410 of the solution. The results demonstrate that solution pH and zeolite dosage are the two most important factors influencing HA adsorption. The optimum experimental conditions were determined to be: 35 °C, Nd:Si molar ratio of 1:100, 2.0 g/L zeolite, pH 4 and 50 min contact time. Under these conditions, the removal efficiencies of UV254, UV410 and COD are 82.70%, 76.00% and 82.10%, respectively, corresponding to a comprehensive removal of 81.02%.

Influence of rare earth (Nd+3) doping on structural and magnetic properties of nanocrystalline manganese-zinc ferrite

Ultrafine nanopowders of Mn0.6Zn0.4Fe2-xNdxO4 (x = 0, 0.04, 0.06, 0.08, and 0.1) were prepared using combustion method. The influence of Nd+3 doping on structural parameters, morphological characteristics and magnetic properties were investigated. Formation of pure spinel phase was confirmed using X-ray powder diffraction (XRPD). Nd+3 doping in Mn-Zn ferrite samples have shown remarkable influence on all the properties that were under investigation. An increase in lattice constant commensurate with increasing Nd+3 concentrations was observed in the samples. The crystallite size calculated from XRPD data and grain size observed from Transmission Electron Microscope showed a proportionate decrement with increment in rare earth doping. An increase in mass density, X-ray density, particle strain and decrease in porosity were the other effects noticed on the samples as a result of Nd+3 doping. The corresponding tetrahedral, octahedral bond lengths and bond angles estimated from XRPD data have also shown substantial influence of the Nd+3 doping. Magnetic parameters namely saturation magnetization (MS) and net magnetic moment ηB, estimated using vibrating sample magnetometer (VSM) were found to depend on the Nd+3 doping. Mössbauer spectroscopy was employed to study the magnetic environment of Mössbauer active ions and detection of superparamagnetic behavior in nanocrystalline rare earth ferrite material. The isomer shift values obtained from Mössbauer spectra indicate the presence of Fe+3 ions at tetrahedral site (A-site) and octahedral site (B-site), respectively.

The influence of composition and heat treatment on the phase composition and mechanical properties of ML19 magnesium alloy

The samples of ML19 magnesium alloy with composition, wt. %: (0,1÷0,6)Zn–(0,4÷1,0)Zr–(1,6÷2,3)Nd–(1,4÷2,2)Y was investigated. The influence of Nd, Y, Zn and Zr on the equilibrium phase transitions temperatures and phase composition using the Thermo-Calc software is established. The Scheil–Gulliver solidification model was also used. We show the significant liquidus temperature increase if zirconium content in alloy is higher than (0,8–0,9) wt.%. Thus, the higher temperature of melting is required (more than 800 °C). This is undesirable if melting in a steel crucibles. The change of equilibrium fractions of phases at different temperatures in ML19 magnesium alloy with a minimum and maximum amount of alloying elements are calculated. A microstructures of the alloys with different amount of the alloying elements in as-cast and heat-treated condition has been studied using scanning electron microscopy (SEM). We investigate the concentration profile of Nd, Y, Zn and Zr in the dendritic cell of as-cast alloy. An amount of neodymium and zinc on the dendritic cell boundaries is increased. High concentration of yttrium is observed both in center and on the boundaries of the dendritic cell. High zirconium concentration mainly observed in the center of the dendritic cells. A small amount of yttrium is also present in a zirconium particles. These particles acting as the nucleation sites for the magnesium solid solution (Mg) during the solidification. The effect of aging temperature (200 and 250 °C) on the hardness of a samples after quenching was studied. Aging at 200 °C provides a higher hardness. Investigated the change of the hardness quenched samples during the aging at 200 °C. The maximum hardness is observed in samples aged for 16-20 hours. The two-stage solution heat treatment for 2 h at 400 °C and 8 h at 500 °C with water quenching and aging at 200 °C for 16 h was performed. This heat treatment enable us to get tensile strength 306 ± 8 MPa and yield strength 161 ± ± 1 MPa with elongation 8,7 ± 1,6 %.

Functional fatigue behavior of NiTi-Cu dissimilar laser welds

Successful integration of NiTi shape memory alloys (SMAs) into a growing range of applications relies on the development of suitable welding and joining techniques. Adoption of welded NiTi SMAs in actuators based on the functional properties presented by these alloys requires the characterization of the functional fatigue of the welded joints. The functional fatigue behavior of NiTi-Cu dissimilar welded joints was investigated in this work. The influence of Nd:YAG laser welding parameters on the microstructure and joint break force were also analyzed. The superelasticity (SE) of the dissimilar joints was analyzed by load/unload cycling tests and the influence of maximum applied load was assessed and compared with the NiTi base material. The effect of the number of cycles on the irrecoverable strain, which develops during the cycling tests, was also investigated. The results show that the stress induced transformation between austenite and martensite is gradually restricted by the plastic deformation generated during the cyclic deformation: the higher the applied load the higher the irrecoverable strain presented by the welded joints. Additionally, the accumulated irrecoverable strain of the NiTi-Cu dissimilar welded specimens accumulates progressively during mechanical cycling.

Pulsed Nd: YAG laser drilling of aerospace materials (Ti-6Al-4V)

This paper studies the influence of Nd:YAG (neodymium-doped yttrium aluminium garnet) laser process parameters on laser drilled hole quality. Ti-6Al-4V of 1 mm and 3 mm thickness were used as the workpiece substrate. The principal findings are mainly based on minimising the taper angle in laser drilled holes, reducing the heat affected zone and reducing the production of spatter. Identification of key process variables associated with laser drilling process is accomplished by trial experimentation. Using the identified key process variables, further experiments were then performed with the assistance of statistical design of experiment (DOE) to find the interaction and individual effects of various laser process parameters on laser drilled hole quality. The lowest taper angle of 1.8 degrees was achieved with use of nitrogen as the assist gas. Furthermore, from the laser process observations, it was found that laser power significantly affects the quality of the laser drilled hole. Increase in laser power would increase the hole size and result in more spatter on the entry hole surfaces. The nozzle focus position substantially influenced the laser drilled hole size. The amount of spatter deposits increased with decrease in the nozzle offset. Increase in laser frequency significantly increased the exit diameter, which resulted in smaller taper angle. Number of pulse required to drill through a workpiece depends on the material properties and physical properties of the material. For 1mm Ti-6Al-4V, a minimum of two pulses was required to successfully removed the material during drilling and a minimum of 4 pulses was required to drill through the same material with 3mm thickness.

Characterization of stainless steel and galvanized iron 0.5 mm thick laser weld joints

The characterization of dissimilar metal welds is a promising area to understand the behavior of the weld joints. The previous study shows the characterization of similar and dissimilar metal welding of 1 mm and above thick sheets for changes in weld bead geometry, chemical composition and mechanical properties at different process parameters. The objective of this paper is to study the influence of Nd: YAG laser welding process parameters on 0.5 mm thick sheets to understand the overall behavioral characteristics of 304 L stainless steel and galvanized iron. The experiments are conducted as per Taguchi’s orthogonal array design matrix. The samples are welded at different process parameters and examined for the variation in the microstructure, chemical composition, weld defects, grain size, phase contents, microstrain and dislocation density across the weld joint. The laser power and pulse duration are significantly affecting process parameters on weld bead geometry, porosity, mixing of metals and weld strength. The factors responsible for the reduction in weld strength are also identified. These findings are useful to understand the overall changes in weld characteristics and variation in mechanical properties. This study also helps to select process parameters for obtaining better quality weld joints in micro component welding.

Structural, magnetic and electrical analysis of La1−x Nd x CrO3 (0.00 &lt; x &lt; 0.15): synthesised by sol–gel citrate combustion method

La1−x Nd x CrO3 (x = 0.00, 0.05, 0.10 and 0.15) perovskites were synthesised successfully through sol–gel citrate combustion method. The influence of Nd in LaCrO3 lattice, microstructure, magnetic and electrical properties was evaluated by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscope (FESEM), vibrating sample magnetometer techniques and impedance analyser. The X-ray diffraction (XRD) and Raman study reveal the structural distortion associated with Nd3+ substitution. The FE-SEM reveals the wide range of grain size between 150 and 500 nm. The M (H) curve of the samples shows weak canted antiferromagnetism and paramagnetism at 5 and 300 K, respectively. The measured field cooled curves (FCC) and zero field cooled magnetisation processes on La1−x Nd x CrO3 (x = 0.00, 0.05, 0.10 and 0.15) show negative magnetisation in the FCC mode, which get enhanced on Nd3+ substitution due to the antiparallel ordering of Nd3+ magnetic moment with respect to Cr3+ magnetic moment. The Neel temperature (T N) of the sample decreases on Nd substitution. The electrical conductivity spectra $$\sigma^{\prime } (f)$$ between 100 Hz and 1 MHz exhibit a single power law in the measured temperature range of 303–453 K. The impedance plot reveals the semiconductor nature with grain boundary for La1−x Nd x CrO3 (x = 0.00, 0.05, 0.10 and 0.15) samples.

Influence of Nd and Y on texture of as-extruded Mg–5Li–3Al–2Zn alloy

Mg–5Li–3Al–2Zn alloys with the additions of Y and Nd were prepared using induction melting furnace under the atmosphere of pure argon; then they were extruded. The textures of the as-extruded alloys were analyzed by pole figures and electron backscatter diffraction. Results show that the addition of a small amount of Nd can weaken the basal texture. The further increase of Nd content has no corresponding further influence on texture. When a small amount of Y is used to replace Nd, the basal texture can be further weakened and the prismatic slip system can be further activated. In the alloy of Mg–5Li–3Al–2Zn–1.2Y–0.8Nd, the basal textures almost vanish.

Composition dependence of phase structure and electrical properties of (1−y)Bi1−x Nd x FeO3−y BiScO3 ceramics

In this work, we have studied a new lead-free ceramic of (1 - y )Bi1 - x Nd x FeO3- y BiScO3 (0.05 £ x £ 0.15 and 0.05 £ y £ 0.15) prepared by a conventional solid-state method, and the influences of Nd and Sc content on their phase structure and electrical properties were investigated in detail. The ceramics with 0.05 £ x £ 0.10 and 0.05 £ y £ 0.15 belong to an R3c phase, and the rhombohedral-like and orthorhombic multiphase coexistence is established in the composition range of 0.125 £ x £ 0.15 and y =0. The electrical properties of the ceramics can be enhanced by modifying x and y values. The highest piezoelectric coefficient ( d 33~51 pC/N) is obtained in the ceramics with x =0.075 and y =0.125, which is superior to that of a pure BiFeO3 ceramic. In addition, a lowest dielectric loss (tan δ ~0.095%, f =100 kHz) is shown in the ceramics with x =0.15 and y =0 due to the involvement of low defect concentrations, and the improved thermal stability of piezoelectricity at 20–600oC is possessed in the ceramics. We believe that the ceramics can play a meaningful role in the high-temperature lead-free piezoelectric applications.

Raising the Thermoelectric Performance of Fe3CoSb12 Skutterudites via Nd Filling and In-Situ Nanostructuring.

p-type skutterudites NdxFe3CoSb12 with x equaling 0.8, 0.85, 0.9, 0.95, 1.0 have been synthesized by solid state reaction followed by spark plasma sintering. The influence of Nd filling on electrical and thermal transport properties has been investigated in the Nd-filled skutterudite compounds in the temperature range from room temperature to 800 K. It was found that the Seebeck coefficient is drastically enhanced via filling Nd in p-Type skutterudites as well as the corresponding power factor although electrical conductivity is reduced. In addition, a large reduction in thermal conductivity is achieved by Nd fillers through rattling effect along with the in-situ nanostructured precipitate through scattering phonons with much wider frequency. These concomitant effects result in an enhanced thermoelectric performance with the dimensionless figure of merit ZT. These observations demonstrate an exciting scientific opportunity to raise the figure-of-merit of p-type skutterudites.

Influence of Nd and Y on texture of as-extruded Mg–5Li–3Al–2Zn alloy

Influence of Nd and Y on texture of as-extruded Mg–5Li–3Al–2Zn alloy

Influence of Nd:YAG laser on intrapulpal temperature and bond strength of human dentin under simulated pulpal pressure.

The aim of this study was to evaluate the effects of simulated pulpal pressure (SPP) on the variation of intrapulpal temperature (ΔT) and microtensile bond strength (μTBS) to dentin submitted to an adhesive technique using laser irradiation. One hundred sound human molars were randomly divided into two groups (n = 50), according to the presence or absence of SPP (15cm H2O). Each group was divided into five subgroups (n = 10) according to Nd:YAG laser energy (60, 80, 100, 120, 140mJ/pulse). The samples were sequentially treated with the following: 37% phosphoric acid, adhesive (Scotchbond Universal), irradiation with Nd:YAG laser (60s), and light curing (10s). ΔT was evaluated during laser irradiation using a type K thermocouple. Next, a composite resin block was build up onto the irradiated area. After 48h, samples were submitted to microtensile test (10kgf load cell, 0.5mm/min). Data were analyzed by two-way ANOVA and Tukey tests (p = 0.05). ANOVA revealed significant differences for ΔT and TBS in the presence of SPP. For ΔT, the highest mean (14.3 ± 3.23°C)(A) was observed in 140mJ and without SPP. For μTBS, the highest mean (33.4 ± 4.15MPa)(A) was observed in 140mJ and without SPP. SPP significantly reduced both ΔT and μTBS during adhesive procedures, lower laser energy parameters resulted in smaller ΔT, and the laser parameters did not influence the μTBS values.

Study the influence of Nd and Co/Cr co-substitutions on structural, electrical and magnetic properties of BiFeO3 nanoparticles

Multiferroic BFO nanoparticles of the compositions Bi1−xNdxFeO3 (x=0.05 and 0.1) and Bi0.9Nd0.1Fe0.95TM0.05O3 (Transition Metals, TM=Co and Cr) have been synthesized by low temperature citric acid assisted auto-combustion route. Subsequently, the co-doping effects on structural, dielectric and ferroelectro-magnetic properties of BFO have been investigated. X-ray diffraction analysis hints phase transformation from rhombohedral to orthorhombic for 10% Nd-substituted BFO. TM addition further modifies structure and co-doped samples possess pseudo-cubic symmetry. Magnetic measurement reveals gradual enhancement in weak ferromagnetic nature with increasing doping. A well-developed magnetic hysteresis loop with high magnetization (Mr~0.35emu/g) and coercive field (Hc~1255Oe) is observed for Nd–Co co-doped sample, whereas other samples exhibit rarely-observed ‘wasp-waisted’ type loops. Dielectric behavior is improved significantly on doping. Temperature-dependent dielectric constant presents a broad peak in the vicinity of Neel׳s temperature (TN) for all the samples, signifying strong magnetoelectric coupling. An increment in TN is also observed as a result of Nd-doping and further on adding TM. Leakage current decreases significantly as a result of reduced oxygen vacancies on substitutions. Therefore, co-substitutions of rare-earth and magnetically active transition ions remarkably enrich electric and magnetic characteristics of BFO, and boost multiferroic feasibility.

The effect of addition of Nd3+ on dielectric properties of Pb[Zr0.45Ti0.45(Zn1/3, Sb2/3)0.1]O3 system

This work aims at, to study the influence of Nd 3+ on the dielectric properties of a ceramics material of general formula: ¶Pb[Zr 0.45 Ti 0 . 45 (Zn 1/3 , Sb 2/3 ) 0.1 ]O 3 and of structure perovskite. ¶The selected samples were prepared by the method of synthesis with solid way. ¶The study of the dielectric properties of the system showed that the values of the permittivity, the resistivity, increase with the addition of Nd +3 1%.

Photoluminescence and thermoluminescence properties of Li₂O-Na₂O-B₂O₃ glass.

Influence of Nd(3+) concentration on the optical and thermoluminescence (TL) properties of melt-annealed synthesized 10 Na2O: 20 Li2O: (70-x) B2O3 : xNd2O3, where 0.1≤ x ≤0.7 (LNB) glasses are determined. The absence of sharp peaks in X-ray diffraction patterns confirms the amorphous nature of the prepared glasses. The photoluminescence spectra under 800 nm laser excitations at room temperature exhibit three prominent peaks centred at 538, 603 and 675 nm corresponding to the transitions of (4)G(7/2) → (4)I(9/2), [(4)G(7/2) → (4)I(11/2), (4)G(5/2) → (4)I(9/2)] and [(4)G(7/2) → (4)I(13/2), (4)G(5/2) → (4)I(11/2)], respectively. The TL glow curve exhibits a prominent peak (T(m)) at 180°C. The best performance of the prepared glass was found at 0.5 mol% of Nd2O3. We achieved a good linearity of TL response against dose between 0.5 to 4.0 Gy. The calculated value of the effective atomic number, Z(eff), is 7.55 which is nearly tissue equivalent (Z(eff) = 7.42). These promising features demonstrate the capability of the aforementioned glass to be used as a radiation dosimeter. The thermoluminescence and optical properties of new compositions of lithium sodium borate glasses doped with Nd(3+) ions were reported. Attractive features were obtained from the TL, PL and UV-Vis light analysis. Three upconversion luminescences permitting green, orange and red emissions were observed.