Copper Micro Research Articles

Investigation on the mechanical and thermal properties of metal-PLA composites fabricated by FDM

PurposeThe aim of this study is to investigate the printing parameters of fused deposition modeling (FDM), a material extrusion-based method, and to examine the mechanical and thermal properties of their polylactic acid (PLA) components reinforced with copper, bronze, and carbon fiber micro particles.Design/methodology/approachTensile test samples were created by extruding composite filament materials using FDM-based 3D printer. Taguchi method was used to design experiments where layer thickness, infill density, and nozzle temperature were the printing variables. Analysis of variance (ANOVA) was applied to determine the effect of these variables on tensile strength.FindingsThe results of this study showed that the reinforcement of metal particles in PLA material reduces strength and increases elongation. The highest tensile strength was obtained when the layer thickness, infill density, and nozzle temperature were set to 100 µm, 60%, and 230 °C, respectively. As a result of thermal analysis, cooper-PLA showed the highest thermal resistance among metal-based PLA samples.Originality/valueIt is very important to examine the mechanical and thermal quality of parts fabricated in FDM with metal-PLA composites. In the literature, the mechanical properties of metal-reinforced composite PLA parts have been examined using different factors and levels. However, the fabrication of parts using the FDM method with four different metal-added PLA materials has not been examined before. Another unique aspect of the study is that both mechanical and thermal properties of composite materials will be examined.

Effect of wire diameter compression ratio on drawing deformation of micro copper wire

A crystal plasticity finite element model was developed for the drawing deformation of pure copper micro wire, based on rate-dependent crystal plasticity theory. The impact of wire diameter compression ratio on the micro-mechanical deformation behavior during the wire drawing process was investigated. Results indicate that the internal deformation and slip of the drawn wire are unevenly distributed, forming distinct slip and non-slip zones. Additionally, horizontal strain concentration bands develop within the drawn wire. As the wire diameter compression ratio increases, the strength of the slip systems and the extent of slip zones inside the deformation zone also increase. However, the fluctuating stress state, induced by contact pressure and frictional stress, results in a rough and uneven wire surface and diminishes the stability of the drawing process.

Correction of some metabolic parameters in cows during the milking period with the help of a feed additive

The article is devoted to the assessment of changes in the clinical condition, hematological parameters, some biochemical blood parameters reflecting the state of protein-carbohydrate metabolism in cows during the milking period, as well as the results of correction of this condition with a feed additive based on humic acids "Fulvat". The article examines the physiological processes occurring in the metabolism of cows during the newbody period and the period of separation, reflects the results of the studies conducted in assessing the dynamics and correction of the main critical indicators in hematological, biochemical blood parameters, as well as in vital changes in cows. The research was carried out using modern techniques, instruments and equipment. The object of the study was cows, 2-3 lactation of a black-and-white breed. All the animals were on tethered maintenance and a balanced diet. 2 groups were formed for research: experimental and control. The animals of the experimental group received the main ration (OR) + the feed additive "Fulvat" for 60 days from the moment of calving; the cows of the control group were kept only on the main ration, without the use of additives in feeding. The feed additive was administered orally with the main diet, mixed with concentrated feed. The total time of observation of the indicators of homeostasis in animals was 60 days. Studies have shown that the feed additive has a beneficial effect on erythropoiesis due to the presence of iron, cobalt, copper and other micro- and macroelements in the chemical composition, increasing the level of hemoglobin in the experimental group on the 60th day of lactation by 19,7 %, reducing the risk of developing a ketogenic situation, increases the level of ionized calcium in the blood of animals, which in 2 times higher, compared with animals in the control group; normalizes the acidity of the scar content in cows of the experimental group and the preservation of the number of infusoria at the physiological level.

Synthesis and in situ oxidation of copper micro- and nanoparticles by arc discharge plasma in liquid

This work presents a one-step controlled method for the synthesis of copper oxide nanoparticles using an arc discharge in deionized water without subsequent thermal annealing. The synthesis conditions were varied by changing the arc discharge current from 2 to 4 A. Scanning electron microscopy images of samples synthesized at discharge current of 2 A revealed the formation of tenorite (CuO) nanopetals with an average length of 550 nm and a width of 100 nm, which had a large surface area. Arc discharge synthesis at 3 and 4 A current modes provides the formation of a combination of CuO nanopetals with spherical cuprite (Cu2O) nanoparticles with sizes ranging from 30 to 80 nm. The crystalline phase and elemental composition of the synthesized particles were identified by X-ray diffraction analysis, Raman spectroscopy and Energy dispersive analysis. As the arc discharge current was raised from 2 to 4 A, two notable changes occurred in the synthesized particles: the Cu/O ratio increased, and the particle sizes decreased. At 4 A, the synthesized particles were from 30 to 80 nm in size and had a spherical shape, indicating an increase in the amount of cuprite (Cu2O) phase. The optical band gap of the aqueous solutions of copper oxide particles also increased from 2 to 2.34 eV with increasing synthesis current from 2 to 4 A, respectively. This suggests that the proposed synthesis method can be used to tune the band gap of the final material by controlling the Cu/O ratio through the current of arc discharge. Overall, this work demonstrates a novel approach to the synthesis of copper oxide nanoparticles with controllable CuO/Cu2O/Cu ratios, which has the potential to be useful in a variety of applications, particularly due to the significant enhancement of photocatalytic abilities and widen the working spectral range.

Determining the tensile strength of fuel surrogate TRISO-coated particle buffer, IPyC, and buffer-IPyC interlayer regions

A novel micro tensile sample fabrication technique for determining the tensile strength of the buffer, IPyC, and buffer-IPyC interlayer regions of surrogate (ZrO2) TRISO fuel particle layers was refined and implemented. Copper micro tensile samples served as baseline materials to verify the methods used. Tensile tests performed in this study, while limited in number, were analysed using standard and Weibull statistics. As expected, the buffer layer was weakest, with an average ultimate tensile strength of 138.70MPa, and the IPyC layer samples were strongest, with an average ultimate tensile strength of 189.74MPa. In the buffer-IPyC interface samples, all breaks occurred in the buffer region, though the average ultimate tensile strength of the samples, 159.80MPa, was between the pure buffer and IPyC samples. These results suggest the interlayer region has unique properties, perhaps associated with pyrocarbon infiltration into the buffer layer during particle coating. All interlayer samples fractured within the buffer side; however, the stress strain behaviour of some of these samples resembled the behaviour of the IPyC layer samples. The buffer and IPyC layer strengths had a normal distribution under Weibull analysis, while the interlayer region had a Rayleigh distribution. Further testing is needed to clarify both the standard and Weibull statistical results.

Effect of Copper, Zinc and Molybdenum Micro Elements in Plants When Using Granular and Liquid Nitrogen Fertilizer with Micro Elements Made from Local Raw Materials

A new type of micronutrient liquid fertilizers was obtained by treating the calcium nitrate porridge obtained on the basis of research with urea (ammonium nitrate, KAS) and micronutrient (Cu Zn Co) salts in the amount necessary for plant growth. The chemical composition, product properties and rheological properties of liquid fertilizers containing microelements were studied, and a laboratory device for the production of liquid fertilizers was created. As a result of preliminary investigations, it was found that copper, zinc, molybdenum, manganese, calcium, magnesium are the most scarce trace elements in the soils of our republic. In order to apply microelements to the soil as fertilizers, the research was carried out in order to find their various sources, to study various industrial residues, to solve the problems of testing, processing of local raw materials and industrial waste containing trace elements a rational technology for obtaining new types of simple and complex liquid, granular and suspended fertilizers was developed, and its agrochemical properties and the amount of microelements in the plant composition and its effect on the absorption of nutrients (NRK), cotton yield and quality parameters of fiber were determined when used in typical gray soil conditions.

In-situ copper ion reduction and micro encapsulation of wood-based composite PCM with effective anisotropic thermal conductivity and energy storage

This work develops metallic wood-based phase change materials (MWPCM) with high-performance anisotropic thermal conductivity by impregnating wood with phase change microcapsules and subsequent in situ chemical deposition of copper inside the wood cell lumen. Phase change material (PCM) is encapsulated by polymer to form phase change microcapsules, which solve the leakage problem effectively. Benefited with the well-aligned and hierarchical porous structure of wood, phase change microcapsules coated with copper layer are orderly confined inside wood vessels and fibers, developing a continuous and anisotropic heat transfer network along the highly oriented transport tissues of wood. The morphology, chemical structure and crystallization of microcapsules and MWPCM are investigated using scanning electronic microscope (SEM), flourier transformation infrared spectroscopy (FTIR) and X-ray diffractometer (XRD), and the thermal storage capacity, thermal stability and thermal conductivity of the developed PCM composites are examined using differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and laser flash diffusivity apparatus (LFA) respectively. The results show that PCM capsules were effectively accommodated in orderly porous wood as a carrier; the radial and longitudinal thermal conductivity of MWPCM reached 0.37 W/(m*K) and 0.53 W/(m*K), which increased by 362% and 211% compared to pure wood, respectively. The anisotropic thermal conductivity of MWPCM enabled an efficient heat transfer along the longitudinal direction and reduced the heat loss in the transverse direction. MWPCM exhibited good thermal energy storage capacity (92.9 J/g and 94.6 J/g) and suitable phase change temperature (11.4 °C and 29.4 °C) for indoor thermal energy management. MWPCM also displayed outstanding shape-stability, excellent thermal stability and temperature regulation, which has a great potential for building energy collecting, storage and management.

Development of High-Strength Geopolymer Concrete Incorporating High-Volume Copper Slag and Micro Silica

The present work investigates the mechanical and chemical characteristics and durability of high-strength geopolymer concrete (HSGPC) developed using high-volume copper slag and micro silica. The objective of the study was to explore the feasibility of deploying high-volume copper slag as a replacement for river sand in the fabrication of high-strength geopolymer concrete. In total, 11 different trials were cast by varying copper slag up to 100% as a potential alternative for the river sand. The mixture of alkaline activators for the preparation of the geopolymer concrete (GPC), such as sodium silicate (Na2SiO3) and sodium hydroxide (12 M NaOH), was used in the ratio 2.5:1. The optimum mix was selected from different copper slag dosages based on the characteristics of the HSGPC, such as mechanical strength and workability. For the selected optimized mix, micro silica was added up to 5% by volume of the binder (i.e., 1%, 2%, 3%, 4% and 5%) to improve the particle packing density of the developed HSGPC mix which in turn further enhances the strength and durability properties. Two different curing methods, including (a) ambient curing and (b) steam curing at 80 °C, were deployed for achieving the polymerization reaction (i.e., the formation of Na-Al-Si-H gel). Experimental outcomes reveal a maximum compressive strength of 79.0 MPa when 2% micro silica was added to the optimized GPC mix. In addition to the mechanical tests, the quality of the developed HSGPC was assessed using the ultrasonic pulse velocity (UPV) tests, water-absorption tests, sorptivity tests and microstructural analyses.

STUDY ON MECHANICAL PROPERTIES OF M30 GRADE CONCRETE BY PARTIALLY REPLACING CEMENT WITH MICRO SILICA AND FINE AGGREGATE WITH COPPER SLAG

Cement, sand, and aggregate are essential for every construction sector to function properly. Sand is a primary ingredient in the manufacturing of mortar and concrete, and it plays an important role in the design of concrete mixes. Because of the deterioration of rivers nowadays, as well as environmental concerns, river sand is becoming increasingly scarce. The lack of availability or scarcity of river sand will have an impact on the building sector; as a result, it is necessary to develop innovative alternative materials to substitute river sand in order to prevent excessive river erosion and environmental damage. Many academics are working on developing alternative materials to sand, with copper slag being one of the most promising candidates. Cobalt slag and micro silica are industrial by-product minerals that are created as a by-product of the copper and ferro-silicon metal manufacturing processes, respectively. The use of copper slag and micro silica in building not only serves to lower the cost of construction, but it also helps to reduce the impact on the environment by utilizing materials that would otherwise be deemed waste. In this study, an attempt has been made to review all of the material that is currently available and to determine the outcomes of numerous researchers in order to offer a strategy that will be appropriate for subsequent research. According to the findings of the study, waste materials or byproducts of industry such as copper slag and micro silica can be advantageously utilized in the preparation of concrete, which not only lowers the cost of concrete but also solves the problem of obtaining river sand, which is also beneficial to the environment.

Tensile and fatigue properties of aluminum and copper micro joints for Li-ion battery pack applications

The current collectors of Li-ion batteries are generally composed of dissimilar materials, such as aluminum and copper that have a thickness of 500 μm. In battery pack welding, existing techniques such as ultrasonics and lasers are ineffective since the materials are micron-thickness, have the same crystal structure as the face-centred cubic, and are highly reflective materials. In the present study, friction stir spot welding (FSSW) is used to join micro sheets of AA1060 and pure copper in a lap configuration. Variations in FSSW process parameters affect friction heat generation. The combination of frictional heat and metal diffusion leads to the formation of intermetallic compounds (CuAl2, CuAl, and Al4Cu9) and a change in IMC thickness. A weld sample with optimal process parameters results in the formation of Al4Cu9, and the IMC thickness is 1.94 μm, yielding a maximum tensile load of ∼1150 N and fatigue strength of 101.24 MPa. The existing study indicates that the skewness of the hysteresis loop is a critical factor in fatigue failure.

Optimization of micro-EDM drilling on titanium alloy (Ti-6AL-4V) using RSM and Neural Network

In modern manufacturing industries, micro machining technology is widely used to machine micro parts for various applications such as in MEMS, die and tool industries, etc. Micro electric discharge machining (Micro-EDM) is widely used in die and tool making. This paper investigates three different input machining parameters such as pulse on time, pulse off time, and servo voltage of micro electric discharge machining performances of tool wear (TW) and Diametrical accuracy (DA) of a hole on titanium alloy (Ti-6Al-4V) using copper micro electrodes of ϕ 400μm. The experiments ate conducted out with the Box-Behnken design of Response Surface Methodology (RSM). The neural network is used for the optimization of multi response by fitting the regression model. ANOVA is also performed to find the significant contribution of the machining parameter. The predicted optimal machining values with the maximum error of 12.72% for tool wear and 8.78% for diametrical accuracy was achieved on comparing with experimental results.

The effect of the ECAP process on the copper micro gears produced by the forward micro-extrusion process

In this research, equal channel angular pressing was employed to improve the mechanical characteristics of initial billets of pure copper in the micro-extrusion process. The micro-extrusion was performed to manufacture the micro gears. Then, the effects of lubrication conditions and mechanical properties of the initial billets were investigated on the formability, microstructure, and microhardness of micro gears. The results declared that microhardness in micro gears manufactured from ECAPed copper was higher compared to annealed samples. The experiments substantiated that microstructural differences depended on the location within the micro gears and initial microstructure of the billets utilized in the micro-extrusion process.

OCT Capillary Depth Measurement in Copper Micro Welding Using Green Lasers

The transition of the powertrain from combustion to electric systems increases the demand for reliable copper connections. For such applications, laser welding has become a key technology. Due to the complexity of laser welding, especially at micro welding with small weld seam dimensions and short process times, reliable in-line process monitoring has proven to be difficult. By using a green laser with a wavelength of λ=515 nm, the welding process of copper benefits from an increased absorption, resulting in a shallow and stable deep penetration welding process. This opens up new possibilities for the process monitoring. In this contribution, the monitoring of the capillary depth in micro copper welding, with welding depth of up to 1 mm, was performed coaxially using an optical coherence tomography (OCT) system. By comparing the measured capillary depth and the actual welding depth, a good correlation between two measured values could be shown independently of the investigated process parameters and stability. Measuring the capillary depth allows a direct determination of the present aspect ratio in the welding process. For deep penetration welding, aspect ratios as low as 0.35 could be shown. By using an additional scanning system to superimpose the welding motion with a spacial oscillating of the OCT beam perpendicular to the welding motion, multiple information about the process could be determined. Using this method, several process information can be measured simultaneously and is shown for the weld seam width exemplarily.

The effect of applied voltage and temperature on growth of copper micro‐ and nanowires in etched ion‐track cellulose nitrate detector

The effects of the applied voltage and temperature on growth of Cu micro- and nanowires electrochemical deposited in the etched ion-track Cellulose Nitrate (CN) detector were investigated. Cellulose Nitrate foils of 96-μm thickness were irradiated with heavy ions (U ions of initial energy 17.7 MeV/nucleon and 16.34 MeV/nucleon). By chemical etching of the latent tracks produced by the heavy ions in CN samples, a porous membrane containing nano- and micro-sized cylindrical open pores were prepared. These porous membranes have been used for fabrication of the nano and microwires. Cu micro- and nanowires were grown by electrochemical deposition of copper into pores using the two-electrode electrochemical cell. The electrochemical deposition process was monitored in real time by recording the current during the growth of the wires. The influence of the deposition parameters such as applied voltage and electrolyte temperature on current versus time curve recorded during the manufacturing of Cu microwires and their structure were studied.

Heat Transfer Rate Optimisation of Ionanofluid Based Heat Sink Using ANSYS

Heat dissipation of various electrical and electronic devices has been a significant concern in the current years of modernisation. Many researchers proved that a liquid-cooled microchannel heat sink (MCHS) is an effective way of removing high heat load. Due to ionic liquids’ unique properties such as negligible volatility, non-flammability, high thermal stability, and ionic conductivity, this liquid is combined with nanofluids to synthesise a new class of potential fluids termed Ionanofluids (ionic liquid-based nanofluids). In this research, a numerical simulation of fluid flow and heat transfer characteristics of MWCNT (Multiwalled Carbon Nanotubes) based Ionanofluids as a coolant in a rectangular-shaped microchannel heat sink is analysed. The Two-step method is used for preparing the studied Ionanofluids consisting of 0.5 wt.% of MWCNT nanoparticles ultra-sonicated with a mixture of propylene glycol and 1-Butyl-3-methylimidazolium chloride ([Bmim][Cl]-ionic liquid) fluids. Copper micro channelled heat sink comprising 1 m channel height, 25 μm of channel diameter, and 0.7 m channel width is modelled and simulated with ANSYS-Fluent. The results showed that the heat transfer coefficient increases about 11.4% while the thermal resistance decreases about 15.18% by using the proposed ionanofluids with the concentration of 0.5 wt.% at Re=2000 compared with that of an MCHS with propylene glycol. Moreover, the pressure drop along the studied MCHS increased up to a maximum of 30 kPa for higher heat gradients. Ionanofluids decreased the thermal resistance and temperature difference between the heated surface of the MCHS and Ionanofluids inlet to a greater extent when validated with pure base fluid and previous studies. From the simulated results, a better cooling performance is observed with Ionanofluids compared to pure propylene glycol (PG) for the proposed microchannel heat sink.

Research on the synergistic effect of megasonic and particles in through mask electrochemical etching process

Through-mask electrochemical etching (TMEE) is one of the main methods to fabricate metal microstructures array in large scale. In deep metal microstructure etching process, lateral corrosion problem seriously affects the etching localization. In this paper, megasonic and particle combined through mask electrochemical etching (MP-TMEE) method was proposed to improve the etching localization in TMEE process. Experimental results show that the etching factor (EF) was greatly improved by MP-TMEE method compared to traditional TMEE. With the use of MP-TMEE, when the feature size of the mask was 100 μm, the average diameter and depth of the etched micro pits were 148.7 μm and 59.9 μm. The use of MP-TMEE instead of TMEE leads to an increase in EF from 1.58 to 2.50. Besides, the mechanism of the synergistic effect of megasonic and the particles in MP-TMEE process was investigated. An erosion theoretical model of passivation film was established and verified by electrochemical impedance spectroscopy (EIS) method. The measurement results of EIS show that the micro pit depth and the passivation film resistance have the opposite variation trend, and the passivation film resistance measurement results are consistent with the trend of the theoretical model. Finally, microstructure arrays involving stainless steel micro pit array and micro pillar array, copper micro pit array and micro pillar array were fabricated using MP-TMEE method.

Surface Properties of Melts Based on Tin

This paper presents the results of the surface properties of the tin-based melts. It has been shown that the best wetting of Al-4 at. % Li grade aluminum, silicon, and piezoceramics are achieved by the eutectics and terectics of tin-aluminum, tin-zinc, and aluminum alloys, respectively. Preliminary photon annealing of the substrates for 3–4 sec improves the wetting of silicon and ceramics. Solder wetting is also improved by the addition of copper and nickel micro powders, alkaline, and alkaline earth elements.

Role of Organic Additives in the Fabrication of Micro Copper Rods by Localized Electrochemical Deposition

In this research, an automated experimental setup to fabricate high aspect ratio copper micro rods using localized electrodeposition was assembled. Using a custom-made microelectrode, copper micro columns were successfully fabricated on copper substrates from an additive-free electrolyte. To expand the capabilities of localized electrochemical deposition as a potential microfabrication technique, the effect of organic additives including Janus Green B (JGB), Polyethylene Glycol (PEG), 3-mercapto-1-propane sulfonic acid (MPSA) on the uniformity of the fabricated structures was studied. Scanning electron microscopy characterization revealed that organic additives play an important role in achieving a uniform and rigid micro rod across its height. An electrolyte containing all three additives (PEG, JGB, MPSA) appears to produce a micro rod with better structural characteristics compared with the case when only two additives are present (PEG, JGB). From this research, designing an electrolyte with proper chemistry appears to be critical to realize optimized fabrication of micro scale features by localized electrodeposition. It could also contribute to presenting the technique as a competitive and reliable micro fabrication alternative to other complex and high-cost technologies.

Capillary and thermal performance enhancement of rectangular grooved micro heat pipe with micro pillars

Due to confined space in micro heat pipes (MHPs), the resulting flow boiling heat transfer suffers from flow instability and low values of critical heat flux. In this paper, to overcome this challenge, different shapes of silicon and copper micro pillars were designed inside the micro axial grooves of silicon-based MHPs and fabricated by MEMS fabrication methods. The capillary rise test and thermal performance test were performed to investigate the wettability and effective thermal conductivity of MHPs. The results showed the performance of MHPs with circular micro pillar was superior to square and diamond shapes. In addition, the hydrophilicy and thermal performance of copper micro pillars were more effective than silicon micro pillars. Comparative study of micro pillars with straight and zigzag patterns showed that the capillary and thermal performance of zigzag pattern was preferable to straight one. In this case, contact angles of Wenzel model for straight and zigzag patterns achieved 24.38° and 18.49°, respectively. Our findings illustrated the micro pillars not only improved the wettability of micro grooves but also increased the heat transfer capability of two-phase flow inside the MHPs.

EFFECT OF ARTIFICIAL CAVITIES ON HEAT TRANSFER AND FLOW CHARACTERISTICS MICROCHANNEL

An experimental investigation was conducted to study single-phase fluid flow and heat transfer in a copper micro channel. To investigate the effect of artificial cavities on fluid flow and single phase heat transfer in micro channel heat sink, two model of straight micro channel recognized as two models (model -1and model -2) were designed and manufactured ,where model-1 have smooth bottom surface while Model-2 have 47 artificial cavities distributed uniformly at the bottom surface along the micro channel length. The two models having the same nominal dimension of 300?m height and 300?m depth while the real dimension value are 367 ?m for width and 296 ?m for depth .De-ionized water was used as the working fluids. Experimental test was conducted at 30?C inlet temperature with Reynolds numbers range from 700 to 2200 covering laminar flow conditions. The experiments were conducted with horizontal micro channel under both adiabatic (for friction factor calculation) and diabatic (for Nusselt number calculation) conditions. The results indicated that the experimental Darcy friction factor can be predicted well with conventional scale fanning friction factor correlations for developing flow in laminar region by shah and London (1978) correlation for two models. Also, the experimental Nusselt number Agree well with each correlation of shah and London (1978) and Mirmanto correlation in laminar region.