Melting Temperature Of Metal Research Articles

Explore the fascinating realm of comparing metal melting curves by applying the equation of state and Lindemann's law

Our research, which is not just theoretical but also has practical implications, is a comprehensive study that aims to find the equation of state needed to calculate the pressure-dependent melting curves of metals. We have introduced a unique model for the melting curve, utilizing equations of state such as those proposed by Srivastava-Pandey and Kholiya. This model has been compared with Lindemann's model and available experimental data. It establishes the relationship between pressure, bulk modulus, pressure derivative of bulk modulus, and volume compression. Our findings show that a significant increase in melting temperature is directly linked to a substantial rise in bulk modulus and a gradual decrease in the first-order pressure derivative of bulk modulus. This study provides insights into understanding the effect of pressure on melting temperature. The present study finds that the equation of state of Srivastava-Pandey is more suitable for describing the melting temperature of metals, which could have significant implications for material science and engineering.

Hypoeutectic Liquid Metal Printing of 2D Indium Gallium Oxide Transistors.

2D native surface oxides formed on low melting temperature metals such as indium and gallium offer unique opportunities for fabricating high-performance flexible electronics and optoelectronics based on a new class of liquid metal printing (LMP). An inherent property of these Cabrera-Mott 2D oxides is their suboxide nature (e.g., In2O3-x), which leads high mobility LMP semiconductors to exhibit high electron concentrations (ne >1019cm-3) limiting electrostatic control. Binary alloying of the molten precursor can produce doped, ternary metal oxides such as In-X-O with enhanced electronic performance and greater bias-stress stability, though this approach demands a deeper understanding of the native oxides of alloys. This work presents an approach for hypoeutectic rapid LMP of crystalline InGaOx (IGO) at ultralow process temperatures (180°C) beyond the state of the art to fabricate transistors with 10X steeper subthreshold slope and high mobility (≈18cm2Vs-1). Detailed characterization of IGO crystallinity, composition, and morphology, as well as measurements of its electronic density of states (DOS), show the impact of Ga-doping and reveal the limits of doping induced amorphization from hypoeutectic precursors. The ultralow process temperatures and compatibility with high-k Al2O3 dielectrics shown here indicate potential for 2D IGO to drive low-power flexible transparent electronics.

Laser light absorption and Brewster angle on liquid metal

Laser light absorption occurs in all laser-based processes and is, therefore, of importance for process simulation input, parameter optimization, and understanding of the occurring phenomena, such as melt pool flow or vaporization effects. Theoretical models were successful in predicting metal absorption for certain cases but often fail in high-temperature situations due to unknown impacts of occurring effects, such as surface irregularities or contaminations. Measuring absorption at high temperatures is challenging, and there are limited literature data available on values further above melting temperatures of metals. In this work, a radiometric measurement method is used to derive absorption values at high temperatures. The results show shifted values from Fresnel predictions and absorption peaks at comparably low incident angles. The decreasing absorption tendency at low incident angles was shown to be possibly induced by multi-interface absorption effects caused by surface layering and Knudsen layer effects. Surface layering was seen to be able to induce a very low Brewster angle comparable to the observations in the measurements and is, therefore, seen as a possible dominant factor in absorption at elevated temperatures.

Formulation for the prediction of melting temperature of metallic solids using suitable equation of states

We presents expressions for the pressure dependence of the melting temperature of metals using Murnaghan, Usual-Taits, and Kholiya equations of state. The predicted model explains the corelation among the pressure, melting temperature, bulk modulus, its first pressure derivative and volume compression at zero pressure. The formalism is then applied to determine the Tm(P) of transition and noble metals such as Cu, Al, Zn, Au, Ag, Mn, Cd, and Mg, over a wide range of pressure up to 35 GPa. It is observed that the Murnaghan equation of state gives accurate result for the metals having higher bulk modulus thus having higher melting temperature. Kholiya equation of state shows closest result with the experimental data for those metals whose bulk modulus is decreasing continuously whereas the trend of variation is similar in Usual-Taits equation of state. The Usual-Taits equation of state, also referred to as the universal equation of state, exhibits the similar trend of variation. This study also sheds light in understanding the quantitative effect of pressure on melting temperature. Obtained results show good agreement with previous experiments and calculations thus justifying the validity of our model.

Change in the melting temperature of metals with an increase in pressure

A new analytical (i.e., without computer modeling) method for calculating the dependence of the melting temperature Tm of a single-component crystal on pressure P is proposed. The method is based on the delocalization melting criterion and does not contain fitting constants. The baric dependences of the melting temperature Tm(P) and its pressure derivative T'm(P) for gold, platinum and niobium in the pressure range: P=0-1000 GPa were calculated by this method. It was shown that the dependences calculated by this method for gold and platinum agree better with the experimental data than the dependences obtained by computer simulation methods. For niobium, the calculated dependence Tm(P) turned out to be steeper, i.e., the value T'm(P) turned out to be larger than in the experiment. It was indicated that this discrepancy might be due both to a decrease in the Lindemann parameter with increasing pressure and to a redistribution of electrons on the s-d-orbitals during compression of transition metals with a BCC structure. Keywords: melting point, pressure, interatomic interaction, gold, platinum, niobium.

Influence of CaO on Physical and Environmental Properties of Granulated Copper Slag: Melting Behavior, Grindability and Leaching Behavior.

Due to its potential pozzolanic activity, granulated copper slag (GCS) has been proven to act as a supplementary cementitious material (SCM) after thermochemical modification with CaO. This modification method reduces cement consumption and CO2 emissions; however, the additional energy consumption and environmental properties are also not negligible. This paper aims to evaluate the economics and environmental properties of thermochemically modified GCS with CaO through the melting temperature, grindability, and heavy metal leaching characteristics. The X-ray fluorescence spectroscopy (XRF) results indicated that the composition of the modified GCS shifted to the field close to that of class C fly ash (FA-C) in the CaO-SiO2-Al2O3 ternary phase diagram, demonstrating higher pozzolanic activity. The test results on melting behavior and grindability revealed that adding CaO in amounts ranging from 5 wt% to 20 wt% decreased the melting temperature while increasing the BET surface area, thus significantly improving the thermochemical modification’s economics. The unconfined compressive strength (UCS) of the cement paste blended with 20 wt% CaO added to the modified GCS after curing reached 17.3, 33.6, and 42.9 MPa after curing for 7, 28, and 90 d, respectively. It even exceeded that of Portland cement paste at 28 d and 90 d curings. The leaching results of blended cement proved that the heavy metal elements showed different trends with increased CaO content in modified GCS, but none exceeded the limit values. This paper provides a valuable reference for evaluating thermochemically modified GCS’s economics and environmental properties for use as SCM.

Ultrasonic Characterization of Porosity in Components Made by Binder Jet Additive Manufacturing

Binder jet metallic additive manufacturing (AM) is a popular alternative to powder bed fusion and directed energy deposition because of lower costs, elimination of thermal cycling, and lower energy consumption. However, like other metallic AM processes, binder jetting is prone to defects like porosity, which decreases the adoption of binder-jetted parts. Binder-jetted parts are sometimes infiltrated with a low melting temperature metal to fill pores during sintering; however, the infiltration is impacted by the part geometry and infiltration environment, which can cause infill nonuniformity. Furthermore, using an infiltration metal creates a complicated multiphase microstructure substantially different than common wrought materials and alloys. To bring insight to the binder jet/infiltration process toward part qualification and improved part quality, spatially dependent ultrasonic wave speed and attenuation techniques are being applied to help characterize and map porosity in parts made by binder jet AM. In this paper, measurements are conducted on binder-jetted stainless steel and stainless steel infiltrated with bronze samples. X-ray computed tomography (XCT) is used to provide an assessment of porosity.

Chemical kinetics modelling for the effect of chimney on diffusion flame in carbon nanotubes synthesis

Hydrocarbon flame syntheses of carbon nanotubes (CNTs) on various metals substrates have been reported in literature, but existing methods are limited to usage of high melting temperature metals substrate due to excessive temperature in conventional diffusion flame burner. To address this limitation, high thermal conductivity chimney is innovatively incorporated into the diffusion burner to control flame temperature. Hence, the aim of this study is to investigate the effect of chimney application on the interaction behaviour between flame temperature profile and concentration of post combustion species distribution of diffusion flame. In this study, Computational Fluids Dynamics (CFD) – Chemical Kinetics (Chemkin) coupling method is used to simulate the flow and transport behaviour of laminar methane-air mixture in combustion environment. Kinetics mechanism is imported into species transport model of Chemkin simulator to further determine the reaction between combustion species and temperature profile of the mixture. Heat transfer models are then integrated into simulation to investigate the cooling effect of chimney during the combustion of methane-air mixture. This numerical simulation study provides insights on effects of chimney application towards cooling, species concentration, flame temperature and paving path for controlling the growth of CNT on low melting temperature metal substrate. Numerical models show improvement in temperature controls, increase in gas species concentration and in surface area that is favourable for growth of CNTs.

Direct writing of self-healing circuits on curvilinear surfaces

Directly written circuits on polymeric housings can reduce weight and enhance flexibility due to the wiring of electronic devices and systems in automotive and aerospace parts. These circuits must conform to a variety of geometries while maintaining electrical conductivity after deformations. To address these challenges, a hybrid copper-based ink has been developed capable of self-healing. Low melting temperature metals such as indium can work as a self-healing agent in response to deformational processes such as thermoforming. A new generation of devices is conceptualized utilizing printable hybrid copper-based ink, sintered and healed within a few milliseconds via intense pulsed light (IPL).

Role of Grain Size and Shape in Superplasticity of Metals

Superplasticity is characterized by an elongation to failure of >300% and a measured strain rate sensitivity (SRS), close to 0.5. The superplastic flow is controlled by diffusion processes; it requires the testing temperature of 0.5Tm or greater where Tm is the absolute melting temperature of metals. It is well established that a reduction in grain size improves the optimum superplastic response by lowering the deformation temperature and/or raising the strain rate. The low-temperature superplasticity (LTSP) is attractive for commercial superplastic forming, in view of lowering energy requirement, increasing life for conventional or cheaper forming dies, improving the surface quality of structural components, inhibiting quick grain growth and solute-loss from the surface layers, thus resulting in better post-forming mechanical properties. This paper will summarize the dependence of superplasticity on grain size and shape in various metallic materials, including ferrous and non-ferrous alloys, which has been considered as an effective strategy to enable the LTSP.

Irregular LIPSS produced on metals by single linearly polarized femtosecond laser

Currently, supra-wavelength periodic surface structures (SWPSS) are only achievable on silica dielectrics and silicon by femtosecond (fs) laser ablation, while triangular and rhombic laser induced periodic surface structures (LIPSS) are achievable by circularly polarized or linear cross-polarized femtosecond laser. This is the first work to demonstrate the possibility of generating SWPSS on Sn and triangular and rhombic LIPSS on W, Mo, Ta, and Nb using a single linearly polarized femtosecond laser. We discovered, for the first time, SWPSS patches with each possessing its own orientation, which are completely independent of the light polarization direction, thus, breaking the traditional rules. Increasing the laser power enlarges SWPSS periods from 4–6 μm to 15–25 μm. We report a maximal period of 25 μm, which is the largest period ever reported for SWPSS, ∼10 and ∼4 times the maximal periods (2.4 μm/6.5 μm) of SWPSS ever achieved by fs and ns laser ablation, respectively. The formation of triangular and rhombic LIPSS does not depend on the laser (power) or processing (scan interval and scan methodology) parameters but strongly depends on the material composition and is unachievable on other metals, such as Sn, Al, Ti, Zn, and Zr. This paper proposes and discusses possible mechanisms for molten droplet generation/spread/solidification, Marangoni convection flow for SWPSS formation, and linear-to-circular polarization transition for triangular and rhombic LIPSS formation. Reflectance and iridescence of as-prepared SWPSS and LIPSS are characterized. It was found that besides insufficient ablation on W, the iridescence density of Ta-, Mo-, Nb-LIPSS follows the sequence of melting temperatures: Ta > Mo > Nb, which indicates that the melting temperature of metals may affect the regularity of LIPSS. This work may inspire significant interest in further enriching the diversity of LIPSS and SWPSS.

Pressure dependence of the Grüneisen parameter and melting temperature of some metals

We have used a method for determining volume dependence of the Grüneisen parameter in the Lindemann law to study the pressure dependence of melting temperatures in case of 10 metals viz. Cu, Mg, Pb, Al, In, Cd, Zn, Au, Ag and Mn. The reciprocal gamma relationship has been used to estimate the values of Grüneisen parameters at different volumes. The results for melting temperatures of metals at high pressures obtained in this study using the Lindemann law of melting are compared with the available experimental data and also with the values calculated from the instability model based on a thermal equation of state. The analytical model used in this study is much simpler than the accurate DFT calculations and molecular dynamics.

Customizing MRI-Compatible Multifunctional Neural Interfaces through Fiber Drawing.

Fiber drawing enables scalable fabrication of multifunctional flexible fibers that integrate electrical, optical and microfluidic modalities to record and modulate neural activity. Constraints on thermomechanical properties of materials, however, have prevented integrated drawing of metal electrodes with low-loss polymer waveguides for concurrent electrical recording and optical neuromodulation. Here we introduce two fabrication approaches: (1) an iterative thermal drawing with a soft, low melting temperature (Tm) metal indium, and (2) a metal convergence drawing with traditionally non-drawable high Tm metal tungsten. Both approaches deliver multifunctional flexible neural interfaces with low-impedance metallic electrodes and low-loss waveguides, capable of recording optically-evoked and spontaneous neural activity in mice over several weeks. We couple these fibers with a light-weight mechanical microdrive (1g) that enables depth-specific interrogation of neural circuits in mice following chronic implantation. Finally, we demonstrate the compatibility of these fibers with magnetic resonance imaging (MRI) and apply them to visualize the delivery of chemical payloads through the integrated channels in real time. Together, these advances expand the domains of application of the fiber-based neural probes in neuroscience and neuroengineering.

Additive Manufacturing by laser-assisted drop deposition from a metal wire

The subject of Additive Manufacturing includes numerous techniques, some of which have reached very high levels of development and are now used industrially. Other techniques such as Micro Droplet Deposition Manufacture are under development and present different manufacturing possibilities, but are employed only for low melting temperature metals. In this paper, the possibility of using a laser-based drop deposition technique for stainless-steel wire is investigated. This technique is expected to be a more flexible alternative to Laser Metal Wire Deposition. Laser Droplet Generation experiments were carried out in an attempt to accurately detach steel drops towards a desired position. High-speed imaging was used to observe drop generation and measure the direction of detachment of the drops. Two drop detachment techniques were investigated and the physical phenomena leading to the drop detachment are explained, wherein the drop weight, the surface tension and the recoil pressure play a major role. Optimised parameters for accurate single drop detachment were identified and then used to build multi-drop tracks. Tracks with an even geometry were produced, where the microstructure was influenced by the numerous drop depositions. The tracks showed a considerably higher hardness than the base wire, exhibiting a relatively homogeneous macro-hardness with a localised softening effect at the interfaces between drops.

The study of volumetric wearing of PCBN/W-Re composite tool during friction stir processing of pipeline steels (X70) plates

Friction stir welding is a solid-state joining/processing technique that offers high strength and productivity, resulting in a microstructure similar to hot working cycles. However, high melting temperature metals such as steels cause excessive wear over welding tools, representing a significant economic issue. Most studies conducted in steels have used polycrystalline cubic boron nitride (PCBN) and W-Re composite tools, which offer a combination of high strength and hardness at high temperatures, along with high-temperature stability. However, even those tools are susceptible to tool wear. In the present study, experimental data was collected during friction stir processing of X70 grade pipeline steel plates, using W-Re and PCBN composite tools under well-controlled conditions. Profilometry and optical microscopy were used to quantify the volume loss at the welding tool due to the number of plunges and the welded distance. Torque and transverse force at the welding tool and the welded bead width were measured and related to the wear process. Tool contamination in boron-nitrogen particles and dissolved tungsten was identified at the stir and hard zones, more substantial at the latter.

Role of amount of council and diameter of copper on metal smelting temperature

This paper discusses the role of the number of turns and the diameter of copper wire on metal melting temperature. The aim is to determine the effect of the number of turns and wire diameter on the temperature produced in the metal smelter. The method used by testing using the number of turns referred to is 20 turns, 25 turns, 30 turns, and a wire diameter of 1 mm, 1.5 mm and 2 mm. The results of the average value of the number of turns that vary, where the number of turns (30) has the highest average temperature value of 681.11 ° C, while the number of turns (25) produces the lowest average temperature of 648.22 ° C, the number of turns (20) the averagetemperature value is 651.11 ° C. and the larger the coil wire diameter is used, the higher the temperature produced. At 2mm, the coil wire diameter has the highest average temperature value of 691.11 ° C, while the coil wire diameter of 1.5mm has the highest average temperature value of 691.11 ° C. The average temperature value is 667.22 ° C, then the coil wire diameter of 1 mm has the lowest average value of 622.11 ° C

Spajanje raznorodnih metala ultrazvučnim zavarivanjem

The dissimilar metal welding always challenges. The different alloys have different physical and mechanical properties. In the case of the electronic component of the car, it needs to establish a joint between dissimilar metals. The useful metals are for this application are copper and aluminium. Even that has good conductivity, corrosion resistance and formability. By fusion welding technologies these thin metal workpiece joining is not a simple technology. To use a solid state welding technology can be a suitable solution to establish a cohesion joint in case of this task. It well-known much suitable technologies, even that all of them has advantages and disadvantages. The choice of solid-state technology is the ultrasonic welding process. In the case of this process, we use pressure and high-frequency vibration for welding. Besides this process, the friction and vibration generated heat is lower than the metal melting temperature. The base of this technology is the ultrasound-assisted high-level formability. The optimization of this dissimilar joining technology parameters needs many pre-welding and testing process. In this work, we wanted to introduce this empirical optimization process.

Features of using linear graphs in developing mathematical model of metal melting process in induction crucible furnace

The use of linear graphs in the development of a mathematical model of metal melting in an induction crucible furnace allows to determine the metal melting temperature and control the excess temperature in the main parts of the furnace. In addition, if it is necessary to optimize the thermal mode of operation of the furnace according to the presented graph conversion method, a graph model of any part of the furnace with the desired thermal parameters can be obtained.

Controlling the Tube Diameter of SWCNTs Using High Melting Point Promotors

A particular control of the diameter of Single Walled-Carbon Nanotube (SWCNT) using Chemical vapor Deposition (CVD) system will enable many promising applications in different fields. Here we demonstrate the growth of SWCNT with good control of diameter (1.5 nm ± 0.7) using a high melting temperature metal (Ru) as a catalyst promotor with the main catalyst Co at 850˚C via CVD. We hypothesis that using high melting temperature metal as a promotor, like Ru can limit the mobility/change in the shape of the formed metal nanoparticles and eventually decrease the effects of Ostwald ripening (OR). FTS-GP is used as a carbon precursor. The results have been verified by high-resolution transmission electron microscopy (HR-TEM), atomic force microscopy (AFM) and multi-excitation Raman.

Layup-only modulization for low-stress fabrication of a silicon solar module with 100 μm thin silicon solar cells

Despite the predominance of solar modules with bulk crystalline silicon solar cells as a result of their high photoconversion efficiency, long-lasting durability, and low cost per electrical watt, the competitive market has elevated the necessity of thinner silicon solar cells to further reduce direct material costs. However, the tabbing and stringing process using high melting temperature soldering in the conventional fabrication method of a silicon solar module is required to alternatingly interconnect adjacent silicon solar cells, which entails significant thermomechanical stress. The lifting up-and-down motions in the layup process of serially stringed silicon solar cells also lead to an unfavourable interfacial stress between metal ribbons and silicon solar cells. Consequently, a considerably poor yield of silicon solar modules with the unbearable breakage loss of thin silicon solar cells is ascribed to such processes. Herein, an innovative solution to interconnect thin silicon solar cells through virtually no thermomechanical stress is proposed by using encapsulants pre-attached with low melting temperature metal ribbons at 139 °C, which allow the interconnection of pre-laid silicon solar cells in the course of the vacuum lamination at 160 °C. The resulting silicon solar modules exhibit a photoconversion efficiency of 19.1 ± 0.1%, which represents 99.9 ± 0.6% of the benchmark photoconversion efficiency of conventional silicon solar modules. The presented layup-only modulization succeeds in fabricating silicon solar modules with 100 μm thin silicon solar cells and it is anticipated to curtail the breakage loss of thin silicon solar cells as well as elevate fabrication productivity by simplifying the fabrication steps of silicon solar modules.