Study of Copper–Nickel Nanoparticle Resistive Ink Compatible with Printed Copper Films for Power Electronics Applications

This paper is focused on copper–nickel nanoparticle resistive inks compatible with thick printed copper (TPC) technology, which can be used for power substrate manufacturing instead of conventional metallization techniques. Two types of copper–nickel inks were prepared and deposited by Aerosol Jet technology. The first type of ink was based on copper and nickel nanoparticles with a ratio of 75:25, and the second type of ink consisted of copper–nickel alloy nanoparticles with a ratio of 55:45. The characterization of electrical parameters, microstructure, thermal analysis of prepared inks and study of the influence of copper–nickel content on electrical parameters are described in this paper. It was verified that ink with a copper–nickel ratio of 55:45 (based on constantan nanoparticles) is more appropriate for the production of resistors due to low sheet resistance ~1 Ω/square and low temperature coefficient of resistance ±100·10−6 K−1 values. Copper–nickel inks can be fired in a protective nitrogen atmosphere, which ensures compatibility with copper films. The compatibility of copper–nickel and copper films enables the production of integrated resistors directly on ceramics substrates of power electronics modules made by TPC technology.

Obtaining tube blanks from copper-nickel alloy МНЖ 5-1 when using a tool made of die steel adjustable austenitic transformation during operation

Purpose. Production of die tool from steel with regulation of austenitic transformation during operation to increase the level of service life during hot deformation of copper-nickel alloy. Research methods. Metallographic, high-temperature X-ray phase and dilatometric analyzes of research steel. Results. The mode of heat treatment (incomplete annealing) of steel 4Х3Н5М3Ф at a temperature of 750±20 °С, obtained by electroslag remelting, allowed to obtain a perlite-sorbitol structure at a hardness of33–34 HRC and allowed better machining by cutting the workpiece alloy. The proposed mode of final heat treatment (hardening 1030±10 °C and tempering 600±5 °C) of the investigated steel, makes it possible to heat the matrix during operation to a temperature of 600 °C. Scientific novelty. The thermal stability of the tool for hot deformation can be significantly increased when using steel with adjustable austenitic transformation during operation. Such steel in the initial state has a ferrite base, and when heated to operating temperatures occurs from α-Fe to γ-Fe conversion and, subsequently, the austenitic structure is preserved throughout the period of high-temperature operation of the stamping tool. It is confirmed that the stamping tool made of steel 4Kh3N5М3F when pressing a copper-nickel alloy works in the temperature range corresponding to the austenitization process. Practical value. Abbreviated technological operation, namely thermo-deformation processing (forging) of ingots obtained by electroslag remelting. Experimental-industrial tests of the die tool of steel 4Х3Н5М3Ф in the manufacture of tube blanks of Ø 67±0,1 mm from a copper-nickel alloy of the МНЖ 5-1 brand are carried out. As a result of research “Artemovsk plant for processing of non-ferrous metals and alloys” (Bakhmut, Donetsk region, Ukraine) at an operating temperature of 900–950 ° C, matrices made of steel 4Х3Н5М3Ф (without deformation-forging) showed stability in three times higher than the matrices from steel 3Х3М3Ф made at the enterprise.

Influence of high-temperature aluminizing treatment on the corrosion resistance of 90/10 copper-nickel alloy

Purpose This study aims to investigate the effect of coatings prepared by the addition of copper-aluminum alloy powder on the corrosion behavior of 90/10 copper-nickel alloy. Design/methodology/approach Coatings of copper-aluminum alloy powder at different contents (Wt.% = 50%, 60%, 70% and 80%) were prepared by the high-temperature heat treatment process. The microstructure and component of the coatings were characterized by scanning electron microscope, X-ray diffraction, energy dispersive spectrometer and X-ray photoelectron spectroscopy. The electrochemical properties of the coating were explored by electrochemical impedance spectroscopy. Findings The results show that the aluminized layer was successfully constructed on the surface of 90/10 copper-nickel alloy, the composition of the coating was composed of copper-aluminum phase and aluminum-nickel phase, the existence of the aluminum-nickel phase was formed by the diffusion of Ni elements within the substrate and because of the diffusion, the Al-Ni phase was distributed in the middle and bottom of the coating more. The Al-Ni phase is considered to be the enhanced phase for corrosion resistance. When the copper-aluminum alloy powder content is 70 Wt.%, the corrosion resistance is the best. Originality/value The enhancement of corrosion resistance of 90/10 copper-nickel alloy by the copper-aluminum alloy powder was revealed, the composition of the aluminized layer and the mechanism of corrosion resistance were discussed.

Synthesis of Tert-Octylsalicylaldoxime and Its Application in Extraction of Cu(II)

The alkyl salicylaldoxime has attracted more and more attention recently due to the complex branched alkyl groups. In this study, a novel alkyl salicylaldoxime, tert-octylsalicylaldoxime, was successfully synthesized by the one-pot method. The yield and purity by the elemental analysis were 96.17 and 94.13%, respectively. The structure was confirmed by elemental analysis, FT-IR, 1H NMR (Nuclear Magnetic Resonance), 13C NMR spectroscopy, and MS. Results showed that tert-octylsalicylaldoxime with a new structure exhibited excellent extraction ability and selectivity for Cu(II) and can be successfully used to recover Cu from copper-nickel alloy electroplating wastewater. Thus, this product has the potential to be used as a powerful copper extractant in the future.

Steel with control austenitic transformation during operation

The intermediate class of steels, which at room temperature belong to the ferritic state, and at operating temperature pass into the austenitic region, are called steels with control of austenitic transformation during operation. The possibility of increasing the service life of such intermediate steels at high temperatures (above the critical point A3) is shown. For the first time, the cast structure and phase-structural state of steel (grade 4Kh3N5М3F) obtained by electroslag remelting were studied. An improved composition of steel (4Kh4N5М3F) for the production of stamping tools for hot pressing of copper, copper and aluminum alloys is proposed. When setting the critical points (A1 and A3) of the investigated steel, which was confirmed by the results of high-temperature X-ray phase analysis, it was possible to optimize the heat treatment (annealing) of steel 4Kh3N5M3F and 4Kh4N5M4F2 in cast and forged condition, which facilitated processing tool. The results of researches on optimization of modes of heat treatment (hardening, tempering) of steel are given. The mechanical properties (strength, toughness, heat resistance) of steel in cast and forged state depending on the tempering and tempering temperature are determined. The tempering brittleness of the experimental steel is determined. An experimental-industrial test of a stamping tool (die dies, extruder parts) made of the investigated steel was carried out. The possibility of using stamped steel with adjustable austenitic transformation for a wide range of operating temperatures of hot deformation of aluminum alloy AK7h (450-500 ºC), copper M1 (600-630 ºC) and copper-nickel alloy MNZh 5-1 (900-950 ºC) with increased service life in comparison with steels of ferrite class 4Kh5МF1S and 3Kh3М3F. Keywords: die steel, composition, thermal treatment, structure, mechanical properties.

Effect of iron on the composition and structure of corrosion product film formed in 70/30 copper-nickel alloy

Purpose This study aims to investigate the effect of changes in iron content in 70/30 copper–nickel alloy on the corrosion process. Design/methodology/approach 70Copper–30Nickel-xFe-1Mn (x = 0.4,0.6,0.8,1.0 Wt.%) alloy were prepared by the high frequency induction melting furnace. The scanning electron microscope, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy were used to analyze the morphology and component of the corrosion product film. Findings The results show that the corrosion resistance of 70/30 copper–nickel alloy added with 1.0%Fe is the best, and the film is divided into inner dense Cu2O composite film and outer hydration loose layer; XRD showed that after adding 1.0% Fe, the content of Cu2(OH)3Cl in the corrosion product film was significantly reduced, while the content of Cu2O remained unchanged; XPS showed that nickel accumulates in the inner layer of corrosion product film; the stage growth mode of the film, the role of nickel in it and the enrichment mechanism of iron in the inner film were summarized and discussed. Originality/value The changes in the composition and structure of the corrosion product film caused by the iron content are revealed, and the mechanism of the difference in corrosion resistance is discussed.

Large scale synthesis of copper nickel alloy nanoparticles with reduced compressibility using arc thermal plasma process

Among the various methods employed in the synthesis of nanostructures, those involving high operating temperature and sharp thermal gradients often lead to the establishment of new exotic properties. Herein, we report on the formation of Cu-Ni metallic alloy nanoparticles with greatly enhanced stiffness achieved through direct-current transferred arc-thermal plasma assisted vapour-phase condensation. High pressure synchrotron X-ray powder diffraction (XRPD) at ambient temperature as well as XRPD in the temperature range 180 to 920 K, show that the thermal arc-plasma route resulted in alloy nanoparticles with much enhanced bulk modulus compared to their bulk counterparts. Such a behaviour may find an explanation in the sudden quenching assisted by the retention of a large amount of local strain due to alloying, combined with the perfect miscibility of the elemental components during the thermal plasma synthesis process.

Effect of atomizing rapid solidification spherical abrasive finishing on the surface quality of copper-nickel alloy

To improve the surface roughness of Copper-Nickel alloy (Cu-Ni alloy) and explore the effect of magnetic abrasive finishing on the surface hardness and hydrophobicity of Cu-Ni alloy, the spherical magnetic abrasives are prepared by atomizing rapid solidification method. The effects of various process parameters on the surface quality of Cu-Ni alloy are explored, and the optimal process parameters of magnetic abrasive finishing of Cu-Ni alloy are obtained. The Neodymium-Iron-Boron permanent magnetic pole is used to grind the workpiece with XK7136C CNC milling machine. Three dimensional profilometer, metallographic microscope, and digital Vickers hardness tester are used to analyze the surface morphology of the workpiece. The hydrophilicity and hydrophobicity of the workpiece are measured by a contact angle goniometer. The effects of spindle speed, feeding rate, processing distance, and abrasive filling amount on the surface quality of workpiece are investigated by the orthogonal experiment and the single factor test. When the spindle speed is 1300 r/min, the feeding rate is 13 mm/min, the processing distance is 1.2 mm, and the abrasive filling amount is 2.0 g, the surface roughness of Cu-Ni alloy decreases from 0.212 to 0.023 μm and the hardness increases from 114 to 119.8 hv. Finally, the mirror effect of Cu-Ni alloy is achieved. When the optimal test parameters are used, the surface roughness of Cu-Ni alloy can be effectively reduced in a short time. The surface quality of the workpiece is improved, the surface hardness of the workpiece is affected to a certain extent, and the service life of the workpiece is prolonged.