Wettability and interfacial reaction mechanism between Ag–Cu alloy and Si3N4 ceramics in air atmosphere

Si2N2O matrix composites were fabricated by solid/gas reaction in air or N2 atmosphere. The effects of atmosphere on the phase and microstructure of the composites were investigated. The reaction mechanism of Si2N2O system was discussed by analysing the variation of the Gibbs free energy with temperature. The effect of N2 and air on sintering of Si2N2O matrix composites was discussed in relation to observed kinetics and thermodynamic calculations. The results showed that gradient structure of Si2N2O matrix composites were obtained in N2 atmosphere. While high N2 concentration was useful for the formation of the pure ?-Si3N4 ceramics, low N2 concentration was proposed to form the pure Si2N2O ceramics. However, in the air atmosphere, structure of the Si3N4/SiO2 composites is homogeneous without the gradient structure appearing. Its composition is a little different as the O2 concentration changes.

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Experimental validation of the reaction mechanism models of dechlorination and [Zn] reclaiming in the roasting steelmaking zinc-rich dust process

High Temperature Materials and Processes ◽

10.1515/htmp-2020-0007 ◽

2020 ◽

Vol 39 (1) ◽

pp. 107-116

Author(s):

Hongyang Wang ◽

Kai Dong ◽

Rong Zhu

Keyword(s):

Reaction Mechanism ◽

Dust Particle ◽

Chemical Reaction ◽

Reaction Mechanisms ◽

Experimental Validation ◽

Step Process ◽

Mass Percent ◽

Mechanism Model ◽

Air Atmosphere ◽

Almost All

AbstractThe reaction mechanism models of dechlorination and [Zn] reclaiming in the roasting steelmaking zincrich dust process are studied. The dust collected from a steelwork contains 63.8% zinc and 3.18% chlorine (mass percent), of which, almost all zinc elements exist in ZnO and ZnCl2 forms, and all the chlorine elements are stored in ZnCl2. When the dust is roasted at above 732∘C in an air atmosphere, the ZnCl2 in the steelmaking zinc-rich dust is volatilized into steam and then oxidized into ZnO. Finding the position where the chemical reaction occurs is the key to determining the reaction mechanisms of dechlorination and [Zn] reclaiming. In this study, two groups of thermal experiments are designed and executed for roasting in different atmosphere environments and at different roasting temperatures. Based on the experiment results, the mechanism model is discussed and built, and the reaction of dechlorination and [Zn] reclaiming is shown to be a multi-step process. Because O2 from the air cannot transmit into the dust particle interior or dust bed effectively, the chemical reaction of [Zn] reclaiming occurs in the external gas environment outside of the dust, where the [Zn] recalcining reaction should be limited by the dynamics of new nucleation of ZnO solids.

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Sintering of Si3N4 Ceramics in Air Atmosphere Furnace(Part 2)-Agglomeration of Packing Powder and Deterioration of Al2O3 Crucible-

Journal of the Ceramic Society of Japan ◽

10.2109/jcersj.112.234 ◽

2004 ◽

Vol 112 (1304) ◽

pp. 234-237 ◽

Cited By ~ 18

Author(s):

Shigetaka WADA ◽

Piyaporn CHAIYAPAK ◽

Supatra JINAWATH ◽

Thanakorn WASANAPIARNPONG ◽

Toyohiko YANO

Keyword(s):

Air Atmosphere ◽

Si3n4 Ceramics

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Influence of Heat Treatment on the Corrosion Resistance of Aluminum-Copper Coating

Metals ◽

10.3390/met10070966 ◽

2020 ◽

Vol 10 (7) ◽

pp. 966

Author(s):

Mieczyslaw Scendo ◽

Slawomir Spadlo ◽

Katarzyna Staszewska-Samson ◽

Piotr Mlynarczyk

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Corrosion Resistance ◽

Electrochemical Corrosion ◽

X Ray Diffraction ◽

Air Atmosphere ◽

Cu Alloy ◽

Acidic Chloride Solution ◽

Acidic Chloride ◽

Electrical Discharge Alloying

Influence of heat treatment on the corrosion resistance of the aluminum-copper (Al-Cu) coating on the aluminum substrate was investigated. The coating was produced by the electrical discharge alloying (EDA) method. The surface and microstructure of the specimens were observed by a scanning electron microscope (SEM). The phase analysis of the composite materials by X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) indicated that intermetallic compounds (i.e., CuAl2 and Cu9Al4) were formed through reactions between Al and Cu. during the EDA process. A significant increase in the hardness of the Al-Cu coating was affected by the improvement of the alloy structure. The heat treatment of materials was carried out at 400 °C or 600 °C in the air atmosphere. A corrosion test of materials was carried out by using electrochemical methods. The corrosive environment was acidic chloride solution. After heat treatment at 400 °C the mechanical properties of the Al/Cu alloy increased significantly and the oxide layer protect of the alloy surface against corrosion. However, after heat treatment at elevated temperature, i.e., 600 °C it was found that the (Al2O3)ads and (CuO)ads coatings were destroyed. The mechanical properties of the Al/Cu alloy decreased, and its surface has undergone deep electrochemical corrosion.

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elemental redistribution and interfacial reaction mechanism for the flip chip Sn-3.0Ag-(0.5 or 1.5)Cu solder bump with Al/Ni(V)/Cu under-Bump metallization during aging

Journal of Electronic Materials ◽

10.1007/s11664-006-0314-7 ◽

2006 ◽

Vol 35 (11) ◽

pp. 2061-2070 ◽

Cited By ~ 25

Author(s):

Guh-Yaw Jang ◽

Jenq-Gong Duh

Keyword(s):

Reaction Mechanism ◽

Interfacial Reaction ◽

Flip Chip ◽

Solder Bump ◽

Under Bump Metallization

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Effects of Different Types of Interlayers on the Interfacial Reaction Mechanism at the Cu Side of Al/Cu Lap Joints Obtained by Laser Welding/Brazing

Materials ◽

10.3390/ma14247797 ◽

2021 ◽

Vol 14 (24) ◽

pp. 7797

Author(s):

Zhu Ruican ◽

Guo Shixiong ◽

Huang Chao ◽

Lei Zhenglong ◽

Zhang Xinrui ◽

...

Keyword(s):

Mechanical Properties ◽

Reaction Mechanism ◽

Laser Welding ◽

Interfacial Reaction ◽

Joint Strength ◽

Ternary Phase ◽

Lap Joints ◽

Wetting Ability ◽

Composite Layers ◽

Different Types

The influence of tin foil and Ni coatings on microstructures, mechanical properties, and the interfacial reaction mechanism was investigated during laser welding/brazing of Al/Cu lap joints. In the presence of a Zn-based filler, tin foil as well as Ni coating strengthened the Al/Cu joints. The tin foil only slightly influenced the joint strength. It considerably improved the spreading/wetting ability of the weld filler; however, it weakened the bonding between the seam and the Al base metal. The Ni coating considerably strengthened the Al/Cu lap joints; the highest tensile strength was 171 MPa, which was higher by 15.5% than that of a joint without any interlayer. Microstructure analysis revealed that composite layers of Ni3Zn14–(τ2 Zn–Ni–Al ternary phase)–(α-Zn solid solution)–Al3Ni formed at the fusion zone (FZ)/Cu interface. Based on the inferences about the microstructures at the interfaces, thermodynamic results were calculated to analyze the interfacial reaction mechanism. The diffusion of Cu was limited by the Ni coating and the mutual attraction between the Al and Ni atoms. The microstructure comprised Zn, Ni, and Al, and they replaced the brittle Cu–Zn intermetallic compounds, successfully strengthening the bonding of the FZ/Cu interface.

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Thermal Decomposition and Kinetics of Pentlandite-Bearing Ore Oxidation in the Air Atmosphere

Metals ◽

10.3390/met11091364 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1364

Author(s):

Kristina Božinović ◽

Nada Štrbac ◽

Aleksandra Mitovski ◽

Miroslav Sokić ◽

Duško Minić ◽

...

Keyword(s):

Reaction Mechanism ◽

Heating Rate ◽

Sulfur Removal ◽

Oxidation Products ◽

Energy Dispersive ◽

Dominant Factor ◽

Initial Sample ◽

Energy Dispersive Spectrometry Analysis ◽

X Ray ◽

Air Atmosphere

The roasting of sulfide ores and concentrates is one of the most important steps in pyrometallurgical metal production from primary raw materials, due to the necessity of excess sulfur removal, present in the virgin material. Pentlandite is one of the main sources for nickel pyrometallurgical production. The knowledge of its reaction mechanism, products distribution during oxidation and reaction kinetics is important for optimizing the production process. Raw pentlandite-bearing ore from the Levack mine (Ontario, Canada) was subjected to oxidative roasting in the air atmosphere. A chemical analysis of the initial sample was conducted according to EDXRF (Energy-Dispersive X-Ray Fluorescence) and AAS (Atomic Adsorption Spectrometry) results. The characterization of the initial sample and oxidation products was conducted by an XRD (X-ray Diffraction) and SEM/EDS (Scanning Electron Microscopy with Energy Dispersive Spectrometry) analysis. Thermodynamic calculations, a phase analysis and construction of Kellogg diagrams for Ni-S-O and Fe-S-O systems at 298 K, 773 K, 923 K and 1073 K were used for proposing the theoretical reaction mechanism. A thermal analysis (TG/DTA—Thermogravimetric and Differential Thermal Analyses) was conducted in temperature range 298–1273 K, under a heating rate of 15° min−1. A kinetic analysis was conducted according to the non-isothermal method of Daniels and Borchardt, under a heating rate of 15° min−1. Calculated activation energies of 113 kJ mol−1, 146 kJ mol−1 and 356 kJ mol−1 for three oxidation stages imply that in every examined stage of the oxidation process, temperature is a dominant factor determining the reaction rate.

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