Reactive wetting of a metal/ceramic system

2002 ◽  
Vol 17 (4) ◽  
pp. 911-917 ◽  
Author(s):  
Jian Chen ◽  
Mingyuan Gu ◽  
Fusheng Pan
Keyword(s):  
Physicochemical Properties ◽  
Interfacial Reaction ◽  
Chemical Reactions ◽  
Metal Matrix ◽  
Metal Substrate ◽  
Reactive Wetting ◽  
Surface Phase ◽  
Alloying Element ◽  
Ceramic System ◽  
Metal Ceramic

The mechanism of reactive wetting of metal/ceramic was investigated on the basis of a detailed description of the thermodynamics of interfacial reactions. The interfacial reaction of the metal/ceramic system has been treated as the reaction between the surface phase of the metal matrix and that of the substrate. It is concluded that reactive wetting is governed not only by the term accounting for the intensity of interfacial chemical reactions but also by the term accounting for the physicochemical properties of the resulting interface. In some cases, only one of them contributes dominantly to wetting. The criteria for the choice of an alloying element to promote wetting should not only include its reactivity with the substrate but also its ability to favorably modify the metal/substrate interface.

Measurement of Plasticity Gradients with Scanning Probe Microscopy

1993 ◽  
Vol 318 ◽  
Author(s):  
James D. Kiely ◽  
Dawn A. Bonnell
Keyword(s):  
Fracture Surface ◽  
Scanning Probe Microscopy ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Ceramic System ◽  
Force Microscopy ◽  
Metal Fracture ◽  
Atomic Force ◽  
Metal Ceramic

ABSTRACTScanning Tunneling and Atomic Force Microscopy were used to characterize the topography of fractured Au /sapphire interfaces. Variance analysis which quantifies surface morphology was developed and applied to the characterization of the metal fracture surface of the metal/ceramic system. Fracture surface features related to plasticity were quantified and correlated to the fracture energy and energy release rate.

scholarly journals Advanced Functional Metal-Ceramic and Ceramic Coatings Deposited by Low-Pressure Cold Spraying: A Review

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1044
Author(s):  
Marcin Winnicki
Keyword(s):  
Cold Spray ◽  
Metal Matrix ◽  
Sol Gel ◽  
Low Pressure ◽  
Ceramic Coatings ◽  
Recent Analysis ◽  
Powder Preparation ◽  
Ceramic Particles ◽  
All Ceramic ◽  
Metal Ceramic

Based on the recent analysis of various databases, cold spray (CS), the newest method among thermal spraying technologies, has received the unabated attention of hundreds of researchers continuously since its invention in the 1980s. The significance of CS lies in the low process temperature, which usually ensures compressive residual stresses and allows for the formation of coatings on a thermally sensitive substrate. This paper concerns the low-pressure cold spray (LPCS) variant employed for forming metal matrix composites (MMCs) with high ceramic contents and all-ceramic coatings. At the very beginning, the influence of LPCS process parameters on deposition efficiency (DE) is analysed. In the next part, the most useful feedstock powder preparation techniques for LCPS are presented. Due to the combination of bottom-up powder production methods (e.g., sol-gel (SG)) with LCPS, the metal matrix that works as a binder for ceramic particles in MMC coatings can be removed, resulting in all-ceramic coatings. Furthermore, with optimization of spraying parameters, it is possible to predict and control phase transformation in the feedstock material. Further in the paper, differences in the bonding mechanism of metal–ceramic mixtures and ceramic particles are presented. The properties and applications of various MMC and ceramic coatings are also discussed. Finally, the exemplary direction of CS development is suggested.

A new advanced experimental setup for in-depth study of the interfacial reaction during reactive wetting

2008 ◽  
Vol 79 (4) ◽  
pp. 043901 ◽  
Author(s):  
Sascha Frenznick ◽  
Martin Stratmann ◽  
Michael Rohwerder
Keyword(s):  
Interfacial Reaction ◽  
Experimental Setup ◽  
Reactive Wetting ◽  
Depth Study

scholarly journals Laser assisted selective chemical metalization of Al2O3 films

2005 ◽  
Vol 3 (4) ◽  
pp. 668-673
Author(s):  
Emil Krumov ◽  
Dimitar Popov ◽  
Nikolay Starbov
Keyword(s):  
Thermal Evaporation ◽  
Chemical Deposition ◽  
Ceramic Surface ◽  
Ceramic System ◽  
X Ray ◽  
Deposited Metal ◽  
Metal Ceramic ◽  
Selective Chemical ◽  
Processing Steps ◽  
Al2o3 Films

AbstractThick aluminum oxide films are prepared on Al plates by anodizing. On the ceramic surface thus obtained a very thin Ag film is deposited via vacuum thermal evaporation. The Ag/Al2O3/Al samples prepared are irradiated by Nd:YAG laser through a suitable metal mask in order to remove the top metal film in the exposed areas. Thus, a negative silver image of the copied mask is obtained. Further, the samples are processed in Ni electroless chemical bath activated by the rest of silver. All processing steps are studied by scanning electron microscopy (SEM). EDS X-ray mapping is applied to study the final distribution of Al and Ni in the processed areas. In addition, the DC conductivity of the fabricated Ni wires obtained is measured. The proposed new method for selective chemical deposition of electroconductive Ni onto laser microstructured Ag/Al2O3/Al samples is simple, versatile and not restricted to the metal/ceramic system studied as well as to the electroless deposited metal.

scholarly journals Evaluation of 5-Hydroxymethylfurfural (HMF) Concentration and Physicochemical Properties in Fresh and Aged Tualang Honey

2020 ◽  
Vol 4 (2) ◽  
pp. 10-16
Author(s):  
Siti Nurfarhana Sabireen ◽  
Siti Amrah Sulaiman ◽  
Rabeta Mohd Salleh ◽  
Wan Ezumi Mohd Fuad
Keyword(s):  
Moisture Content ◽  
Physicochemical Properties ◽  
Chemical Reactions ◽  
High Performance ◽  
Hplc Method ◽  
Human Consumption ◽  
Total Acidity ◽  
Storage Duration ◽  
Tualang Honey

The quality and purity of honey are generally indicated by the physicochemical properties including 5-hydroxymethylfurfural (HMF) level, a neo-formed contaminant with genotoxic potential. The concentration of HMF in honey usually increases as storage duration prolonged. This study investigated the differences in the physicochemical properties and the HMF concentration of fresh (stored within six months) and aged (stored for four years) tualang honey (TH), as well as the correlation between these two main parameters. Each of the physicochemical properties of TH was evaluated using standard established protocols. Meanwhile, the determination of HMF concentrations was conducted using High Performance Lipid Chromatography (HPLC) method. Results obtained indicated that the HMF contents in fresh TH (27 mg/kg) was found to be lower whereas aged TH sample contained greatly higher concentration (1426 mg/kg) when compared to the international recommended value of HMF for tropical honeys (< 80 mg/kg). The physicochemical properties (pH, free acids, lactones, total acidity and moisture content) of TH showed significant correlation with HMF concentration. These parameters could be used as rapid assessments for TH quality from different storage periods. The current findings suggest that there were significant modifications in the chemical reactions between TH of different storage durations. TH stored for four years might be not suitable and safe for human consumption. Keywords: physicochemical properties, 5-hydroxymethylfurfural, aged honey, storage duration

Investigation of Flux-Less Soldering of Metal Matrix Composite and Ceramics by Use of Zn Solder

2018 ◽  
Vol 759 ◽  
pp. 29-34
Author(s):  
Roman Koleňák ◽  
Igor Kostolný
Keyword(s):  
Metal Matrix Composite ◽  
Metal Matrix ◽  
Ceramic Composite ◽  
Bond Formation ◽  
Hot Plate ◽  
Soldering Temperature ◽  
Metal Ceramic ◽  
Transient Zone ◽  
Microstructural Studies ◽  
Al Matrix

The work was dealing with direct soldering of Al2O3 ceramics and a metal/ceramic composite (MMC) with Al matrix. The joints were fabricated by application of flux-less process by use of a hot plate at the assistance of ultrasound with frequency of 40 kHz. The experiments were performed by use of Zn6Al6Ag solder. Wetting was attained on both substrates. The joints of a good quality were fabricated. The soldering temperature was 420 °C. The microstructural studies of interface have revealed a transient zone of Al dissolving on the side of MMC and formation of Zn oxides on the side of ceramics, which were responsible for bond formation.

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