scholarly journals Characterization of Si3N4-Al interface after corrosion tests

Cerâmica ◽  
2003 ◽  
Vol 49 (312) ◽  
pp. 223-227 ◽  
Author(s):  
C. dos Santos ◽  
S. Ribeiro ◽  
K. Strecker ◽  
C. R. M. da Silva
Keyword(s):  
Corrosion Resistance ◽  
Elevated Temperatures ◽  
Mechanical Stability ◽  
X Ray Diffraction ◽  
Crucible Material ◽  
High Corrosion Resistance ◽  
X Ray ◽  
High Corrosion ◽  
Metallurgical Processes

Silicon nitride is a covalent ceramic material of high corrosion resistance and mechanical stability at elevated temperatures. Due to these properties, its use in metallurgical processes, such as the casting of alloys, is increasing. Therefore, the characterization of the interface between Si3N4 and the casted metal is of great importance to investigate possible interactions, which might deteriorate the ceramic mould or contaminate the metal. In this work, the use of Si3N4 as crucible material for Al-casting has been studied, by investigating the corrosion attack of liquid Al at a temperature of 1150 ºC during 30 days in air. The interface was characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. It has been found that due to superficial oxidation two oxide layers form - SiO2 on Si3N4 and Al2O3 on Al - which effectively hinder further reactions under the conditions studied, confering high corrosion resistance to the Si3N4 crucible.

scholarly journals A non–destructive compositional analysis of thin surface films formed on W–xTa alloys by angle resolved X–ray photoelectron spectroscopy

BIBECHANA ◽  
2012 ◽  
Vol 8 ◽  
pp. 8-16
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Photoelectron Spectroscopy ◽  
Compositional Analysis ◽  
Surface Films ◽  
Concentration Gradients ◽  
High Corrosion Resistance ◽  
X Ray ◽  
High Corrosion ◽  
Sputter Deposited ◽  
Non Destructive

Synergistic effect of the simultaneous additions of tungsten and tantalum in the extremely high corrosion resistance properties of the spontaneously passivated sputter–deposited W–xTa alloys was investigated using a non-destructive angle resolved X-ray photoelectron spectroscopy (angle resolved XPS) techniques in this study. In-depth surface analyses of the thin passive films formed on the spontaneously passivated amorphous/nanocrystalline W–xTA alloys using angle resolved XPS analyses revealed that the high corrosion resistance of the alloys is mostly due to the formation of homogeneous passive double oxyhydroxide films consisting of Wox and Ta4+ cations with a small concentration gradients in–depth particularly after immersion between 20–168 h in 12 M HCl solution open to air at 30°C. Consequently, tantalum metal acts synergistically with tungsten in enhancing the spontaneous passivity as well as the high corrosion resistance of the sputter–deposited binary W–xTa alloys in 12 M HCl solution.Keywords: Sputter deposition; W–xTa alloys; 12 M HCl; Take-off angleDOI: http://dx.doi.org/10.3126/bibechana.v8i0.4784BIBECHANA 8 (2012) 8-16

Joining and characterization of SS-430 using microwave hybrid heating technique

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nalin Somani ◽  
Navjot Singh ◽  
Nitin Kumar Gupta
Keyword(s):  
Elevated Temperatures ◽  
Inert Atmosphere ◽  
X Ray Diffraction ◽  
Content Type ◽  
Hybrid Heating ◽  
X Ray ◽  
Microwave Hybrid Heating ◽  
Metallurgical Study ◽  
Worn Surface

Purpose The purpose of this paper is to based upon the joining and characterization (mechanical and metallurgical) of ferritic stainless steel (SS)-430 using a microwave hybrid heating (MHH) phenomenon. Design/methodology/approach The preliminary experiments were conducted using nickel-based powder as interface material using a domestic microwave oven at a frequency of 2.45 GHz and 900 W power for 720 s. The processed joint was metallurgically characterized by means of X-ray diffraction, Energy-dispersive X-ray spectroscopy and Field emission scanning electron microscopy. Mechanical characterization was done by means of tensile and Vickers’ microhardness testing to check the hardness and strength of the joint. Findings The metallurgical study revealed that the microstructure and formation of numerous phases of Fe2Si3 accompanied by chromium and nickel carbides. The average hardness of 359 Hv at the center of the joint and 637 Hv around the boundaries of the joint was observed. The tensile strength of the joint was observed to 471 MPa with an elongation of 9.02%. The worn surface of the joint signifies the presence of plastic deformation and it was limited due to the presence of harder phases such as Ni3Si and Ni3C. Research limitations/implications The concept of microwave joining of metals is a very challenging task as the temperature can not be controlled in the inert atmosphere of the microwave. It has been also observed that at certain elevated temperatures, the material starts absorbing the microwaves; which is unknown. So, a more intensive study is required to overcome these kinds of limitations. Practical implications MHH technique can be used to process different materials such as ceramics, composites and polymers. SS-430 joined by microwave heating is highly corrosion resistive and has wide applications in refrigerators cabinet panels, dishwasher linings, chimney liners, lashing wires, etc. Originality/value As of the author’s best knowledge, no work has been reported on the joining of SS-430 which has huge potential in the industries. Also, no work has been reported on the characterization of microwave joined SS-430.

scholarly journals Angle resolver X-ray photoelectron spectroscopic analysis of the passive film of the corrosion-resistant W-32Zr alloy in 12 M HCl solution

2015 ◽  
Vol 49 (2) ◽  
pp. 103-110
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Synergistic Effects ◽  
High Corrosion Resistance ◽  
Corrosion Resistant ◽  
X Ray ◽  
High Corrosion ◽  
Average Corrosion Rate ◽  
Sputter Deposited ◽  
Zirconium Metal ◽  
Hcl Solution

The sputter-deposited amorphous W-32Zr alloy was passivated spontaneously and showed a fairly high corrosion resistance in 12 M HCl solution in open air at 30°C. The average corrosion rate of the W-32Zr alloy (i.e., 5.2 × 10-3 mm/y) was found to be lower than those of alloy-constituting tungsten and zirconium elements. Such synergistic effects of simultaneous addition of tungsten and zirconium in the W–32Zr alloy was investigated by corrosion tests, electrochemical measurements and angle resolved X-ray photoelectron spectroscopic (ARXPS) analyses. High corrosion resistance of the binary W–32Zr alloy is mostly due to the formation of homogeneous passive oxyhydroxide film consisting of Wox and Zr4+ cations with a small concentration gradient in–depth from ARXPS analysis. Consequently, zirconium metal acts synergistically with tungsten in enhancing the anodic passivity as well as the corrosion resistance properties of the sputter–deposited W–32Zr alloy in 12 M HCl solution open to air at 30°C. DOI: http://dx.doi.org/10.3329/bjsir.v49i2.22004 Bangladesh J. Sci. Ind. Res. 49(2), 103-110, 2014

Growth and Characterization of a Combinatorial Array of Mixed-Phase Magnesium-Aluminum Thin-Film Alloys

2007 ◽  
Vol 1056 ◽  
Author(s):  
Charles Olk ◽  
Daad B. Haddad
Keyword(s):  
Elevated Temperatures ◽  
Mixed Phase ◽  
Al Alloy ◽  
Structural Components ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mg17al12 Phase ◽  
Wide Range ◽  
Compositional Characterization

ABSTRACTCombinatorial gradient-controlled sputter deposition has been employed to produce a library of 100 separate thin films with a wide range of Mg-Al alloy compositions. We have successfully isolated the â (Mg17Al12) phase in polycrystalline films for investigation. The presence of the â phase has been found to be desirable for increasing corrosion resistance; however, in structural components under tensile loading and/or at elevated temperatures, the â phase precipitates undergo coarsening which induces poor creep behavior in several common alloys. We have also synthesized amorphous Mg-Al and mixed-phase compositions as identified by X-ray diffraction measurements. Details of the growth procedure as well as structural and compositional characterization are presented.

Fabrication and Characterization of Ni-TiO2 Nanocomposite Coatings and Their Corrosion Resistance Behaviors

2011 ◽  
Vol 688 ◽  
pp. 217-222 ◽  
Author(s):  
Jian Jun Hao ◽  
Yan An Bai ◽  
Chong Rui Wang ◽  
Xin Yuan Liu
Keyword(s):  
Corrosion Resistance ◽  
Nickel Coating ◽  
Electrochemical Techniques ◽  
Nanocomposite Coatings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Excellent Corrosion Resistance ◽  
Watts Bath ◽  
Fabrication And Characterization

Ni-TiO2 nanocomposite coatings have been successfully fabricated via a route electrodeposition from nickel Watts bath containing nano-TiO2 particles, and characterized by scanning electron microscopy (SEM),X-ray diffraction(XRD), energy dispersive X-ray spectroscopy (EDS)and electrochemical techniques. The influence of preparation parameters on the properties of the coatings were investigated. The obtained results indicated that nano-TiO2 particles were distributed uniformly in the Ni matrix. It was found that the Ni-TiO2 nanocomposite coatings exhibited more excellent corrosion resistance and microhardness in comparison with pure nickel coating.

Effect of Heat Treatment on the Corrosion Behaviour of a Mg-Y Alloy in Chloride Medium

2010 ◽  
Vol 636-637 ◽  
pp. 491-496 ◽  
Author(s):  
M. Carboneras ◽  
Claudio J. Múnez ◽  
Pilar Rodrigo ◽  
M. Dolores Escalera ◽  
Maria Dolores López ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Elevated Temperatures ◽  
Corrosion Behaviour ◽  
X Ray Diffraction ◽  
Chloride Medium ◽  
X Ray ◽  
Technology Applications ◽  
Mechanical Properties And Corrosion ◽  
Surface Examination

Corrosion behaviour of a Mg-Y alloy (commercial WE54) has been studied. This alloy presents excellent retention of mechanical properties and corrosion resistance at elevated temperatures, a combination of properties that can be of interest in many technology applications. To evaluate the effect of heat treatment on the corrosion resistance, WE54 samples in extruded state and after T6 heat treatment were studied. Corrosion behaviour was evaluated by electrochemical and immersion tests in 3.5 wt.% NaCl solution at room temperature and neutral pH. Surface examination was carried out by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD). It was found that corrosion resistance of the magnesium alloy WE54 in chloride medium was improved by applying the heat treatment to the material, a fact that was correlated with the developed microstructure in T6 condition.

scholarly journals Synthesis, Growth, Optical, Structural and Mechanical Characterization of SPNP and KPNP Single Crystal using Ethanol as a Solvent

2019 ◽  
Vol 8 (4) ◽  
pp. 7782-7785
Keyword(s):  
Single Crystal ◽  
Mechanical Stability ◽  
Green Light ◽  
Hardness Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Window ◽  
Uv Visible ◽  
Vicker’S Microhardness

Single crystals of sodium para nitro phenol (SPNP) and potassium para nitro phenol (KPNP) was synthesized at room temperature by slow evaporation solution growth technique using ethanol as a solvent upto the size of 12 × 3 × 2 mm3 and 15 × 2 × 2 mm3 respectively. The grown crystals were characterized by UV- Visible, photoluminescence, Kurtz- Perry test, single crystal X-ray diffraction analysis and Vicker’s microhardness studies. Structural identification of grown crystals was done by single crystal X-ray diffraction and it shows both the crystals are belongs to triclinic crystal system. The SPNP and KPNP crystal emits green light radiation as evident from the PL measurement. The UV -Visible study revealed that the grown crystal has high transmission window with cut off wavelength of 207 nm and 208 nm respectively. And also the direct optical band gap was estimated to be 3.23 eV and 3.20 eV using Tauc’s plot. The SHG output of grown crystals was recorded by Kurtz Perry technique and it is found to be nearly five times greater than the reference KDP. The Vickers hardness test confirms the mechanical stability of the material.

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