Experimental investigation and thermodynamic calculation of Ni–Al–La ternary system in nickel-rich region: A new intermetallic compound Ni2AlLa

The phase equilibrium of the Ni–Al–La ternary system in a nickel-rich region was observed at 800 °C and 1000 °C using scanning electron microscopy backscattered electron imaging, energy dispersive X-ray spectrometry and X-ray diffractometry. The solubility of Al in the Ni5La phase was remeasured at 800 °C and 1000 °C. Herein, we report a new ternary phase, termed Ni2AlLa, confirmed at 800 °C. Its X-ray diffraction (XRD) pattern was indexed and space group determined using Total Pattern Solution (TOPAS), and the suitable lattice parameters were fitted using the Pawley method and selected-area electron diffraction. Ni2AlLa crystallizes in the trigonal system with a space group R3 (no. 146), a = 4.1985 Å and c = 13.6626 Å. A self-consistent set of thermodynamic parameters for the Al–La and Ni–La binary systems and the Ni–Al–La ternary system includes a Ni2AlLa ternary phase, which was optimized using the CALPHAD method. The calculated thermodynamic and phase-equilibria data for the binary and ternary systems are consistent with the literature and measured data

Development of Bottom-Blowing Copper Smelting Technology: A Review

Bottom-blowing copper smelting technology was initiated and developed in China in the 1990s. Injection of oxygen-enriched high-pressure gas strongly stirs the molten bath consisting of matte and slag. Rapid reaction at relatively lower temperatures and good adaptability of the feed materials are the main advantages of this technology. Development and optimisation of bottom-blowing copper smelting technology were supported by extensive studies on the thermodynamics of the slag and the fluid dynamic of the molten bath. The history of technological development and fundamental studies related to this technology are reviewed in this paper

Phase Equilibrium Study of Rare Earth Oxide–Fluoride Salt System: A Review

The applications of rare earth metals and alloys are becoming increasingly widespread and there is a strong market demand. Currently, most of the production enterprises adopt the fluoride–oxide system for electrolytic preparation of rare earth metals and alloys. The solubility of rare earth oxides in molten salt directly affects the selection of operational parameters in the electrolysis process. When the added amount of RE2O3 is less than its solubility, it leads to a decreased electrolytic efficiency. Conversely, an excessive amount of oxide is prone to settle at the bottom of the electrolytic cell, impeding smooth production. The RE2O3 solubility in the fluoride salt can be represented by the phase equilibrium of the RE2O3-REF3-LiF system. The isothermal lines in the primary phase field of rare earth oxide represent the solubility of the oxide in the fluoride salt at the corresponding temperature. This paper outlines the research methods and experimental results on the phase equilibria of the RE2O3-REF3-LiF system. The characteristics and existing problems in the current phase equilibrium study are analyzed. The solubility data of RE2O3 are expressed in the forms of ternary and pseudo-binary phase diagrams of the RE2O3-REF3-LiF system, providing theoretical guidance for the establishment of an accurate and reliable rare earth electrolysis system database and the optimization of electrolytic processes

The Evaluation Index System of Innovation-Driven Capability of Chinese Manufacturing Industry Based on Factor Analysis

In China’s new normal, a strategy named “Made in China 2025” was proposed to speed up the manufacturing’s transformation and upgrading. The hardship of China’s manufacturing industry transformation and upgrading are the limit capability of independent innovation, the complexity and variability for competitive environment and the existence of institutional hurdles. At present, China is facing the powers of the industry from manufacturing to major, The paper will use factor analysis method to construct the evaluation index system of innovation-driven ability of Chinese manufacturing industry, and established evaluation model of innovation-driven ability of Chinese manufacturing industry. Based on the analysis of the model, the paper will propose the innovation driving strategy to speed up manufacturing transformation and upgrading

Enhanced Productivity of Bottom-Blowing Copper-Smelting Process Using Plume Eye

Bottom-blowing copper smelting is a bath smelting technology recently developed in China. It has the advantages of good adaptability of raw materials, high oxygen utilization and thermal efficiency, and flexible production capacity. Plume eye is a unique phenomenon observed in the bottom-blowing copper-smelting furnace where the slag on the surface of the bath is pushed away by the high-pressure gas injected from the bottom. The existence of plume eye was first confirmed by analyzing the quenched industrial samples collected above the gas injection area and then investigated by laboratory water model experiments. Combining the plant operating data and the smelting mechanism of the copper concentrate, the role of the plume eye in bottom-blowing-enhanced smelting is analyzed. It reveals that the direct dissolution of copper concentrate as a low-grade matte into the molten matte can significantly accelerate the reactions between the concentrate and oxygen. The productivity of the bottom-blowing furnace is therefore increased as a result. The effects of the gas flow rate and thickness of the matte and of the slag layer on the diameter of the plume eye were studied using water-model experiments. It was found that increasing the gas flow and the thickness of the matte and reducing the thickness of the slag can increase the diameter of the plume eye. This work is of great significance for further understanding the copper bottom-blowing smelting technology and optimizing industrial operations

The Evaluation Index System of Innovation-Driven Capability of Chinese Manufacturing Industry Based on Factor Analysis

In China’s new normal, a strategy named “Made in China 2025” was proposed to speed up the manufacturing’s transformation and upgrading. The hardship of China’s manufacturing industry transformation and upgrading are the limit capability of independent innovation, the complexity and variability for competitive environment and the existence of institutional hurdles. At present, China is facing the powers of the industry from manufacturing to major, The paper will use factor analysis method to construct the evaluation index system of innovation-driven ability of Chinese manufacturing industry, and established evaluation model of innovation-driven ability of Chinese manufacturing industry. Based on the analysis of the model, the paper will propose the innovation driving strategy to speed up manufacturing transformation and upgrading

Effect of Y-La Addition on Interfacial Reaction and Cyclic Oxidation Behavior of Nickel-based Single Crystal Superalloy

Y-La was added into the second generation of nickel base single crystal superalloy and two kinds of alloy castings with Y-La content of 5.26 × 10–4%(mass fraction, ) Y + 6.05 × 10–4% La and 47.64 × 10–4% Y + 69.09 × 10–4% La were obtained after directional solidification. The effect of Y-La content on the interface reaction between alloy melts and Al2O3 based ceramics during directional solidification was investigated. The effect of alloy content on oxidation resistance of alloy at 1100 oC under cyclic oxidation was studied. The microstructure at the interface between alloy and mould, as well as the surface cross-section and fracture morphologies of the specimens, was characterized by means of scanning electron microscope (SME) with an energy-dispersive spectroscopy attachment. The phases of the oxides were identified by X-ray diffraction. The results show that the increase of Y-La content promotes the interfacial reaction, which makes the reaction layer thicker and more complex. The main reaction products are oxides containing Y and La. The addition of Y-La obviously improves the oxidation resistance of the alloy and reduces the exfoliation of the oxide film on the surface of the alloy. However, excessive Y-La will deteriorate the oxidation resistance of the alloy, accelerate the oxidation weight gain rate of the alloy. And the oxide film of the alloy surface has obvious traces of exfoliation, more holes and serious internal oxidation

Effect of Rare Earth Y on Microstructure and Properties of Sn-58Bi Solder Alloy

Sn-58Bi-xY alloys with different Y contents (x = 0.0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5% (mass fraction, the same below )) were fabricated in a vacuum furnace in nitrogen atmosphere. Microstructure, phase composition, melting characteristic, wettability and hardness of the alloys were investigated, and the influence of the rare earth Y on the formation of intermetallic compound among Sn-58Bi/Cu were analyzed, and the shear strength were test. The results show that the Sn-Bi microstructure is refined, and the microstructure of Sn-58Bi-xY is rich in Sn phase, Bi phase and eutectic microstructure of layered structure. The rare earth Y is distributed in rich Bi phase evenly. The melting points and melting ranges are less affected with the Y addition. The wettability of Sn-58Bi alloys reduces when the Y contents increase, but the hardness of Sn-58Bi alloys increases and reaches the maximum value 24.18HV when the content of Y is 0.4%. Rare earth Y can improve the shear strength of Sn-58Bi-xY/Cu solder joints, and the shear strength of the joints reach the maximum value 53.55 MPa when the content of Y is 0.2%. Y can promote the reaction of Sn-58Bi solder with Cu during welding and forming Cu6Sn5 intermetallic compound