Intermetallic Particles-Induced Pitting Corrosion in 6061-T651 Aluminium Alloy

2011 ◽  
Vol 690 ◽  
pp. 389-392 ◽  
Author(s):  
Kalenda Mutombo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Aluminium Alloy ◽  
Pitting Corrosion ◽  
Chloride Solution ◽  
Nacl Solution ◽  
X Ray ◽  
Intermetallic Particles ◽  
The Matrix ◽  
Scanning Electron

The polished 6061-T651 aluminium alloy was immersed in 3.5% NaCl solution with about 7 ppm dissolved oxygen. Scanning Electron Microscopy equipped with Energy dispersive X-ray Spectroscopy revealed the presence of Al-Si-Fe-containing particles that acted as cathodic sites and promoted the matrix dissolution. The effect of pH and chloride solution is assessed.

Characteristics of Ni–Cr–Fe laser clad layers on EA4T steel

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744031
Author(s):  
Wenjing Chen ◽  
Hui Chen ◽  
Yongjing Wang ◽  
Congchen Li ◽  
Xiaoli Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cladding Layer ◽  
Metallurgical Bonding ◽  
The Matrix ◽  
Feeding Speed ◽  
Upper Bainite ◽  
Scanning Electron

The Ni–Cr–Fe metal powder was deposited on EA4T steel by laser cladding technology. The microstructure and chemical composition of the cladding layer were analyzed by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The bonding ability between the cladding layer and the matrix was measured. The results showed that the bonding between the cladding layer and the EA4T steel was metallurgical bonding. The microstructure of cladding layer was composed of planar crystals, columnar crystals and dendrite, which consisted of Cr2Ni3, [Formula: see text] phase, M[Formula: see text]C6 and Ni3B phases. When the powder feeding speed reached 4 g/min, the upper bainite occurred in the heat affected zone (HAZ). Moreover, the tensile strength of the joint increased, while the yield strength and the ductility decreased.

scholarly journals The Influence of A Mo Addition on the Interfacial Morphologies and Corrosion Resistances of Novel Fe-Cr-B Alloys Immersed in Molten Aluminum

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 256 ◽  
Author(s):  
Zicheng Ling ◽  
Weiping Chen ◽  
Weiye Xu ◽  
Xianman Zhang ◽  
Tiwen Lu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Probe ◽  
Molten Aluminum ◽  
Dendritic Structure ◽  
H13 Steel ◽  
X Ray ◽  
Transmission Electron ◽  
The Matrix ◽  
Scanning Electron

The influence of a Mo addition on the interfacial morphologies and corrosion resistances of novel Fe-Cr-B alloys in molten aluminum at 750 °C was systematically investigated using scanning electron microscopy, X-ray diffractometer, electron probe microanalysis, and transmission electron microscopy. The results indicated that Mo could not only strengthen the matrix but also facilitate the formation of borides. Furthermore, the microstructures of Mo-rich M2B boride changed from a local eutectic net-like structure to a typical coarse dendritic structure and a blocky hypereutectic structure with increasing Mo addition. This was true of the blocky Mo-rich M2B boride, rod-like Cr-rich M2B boride and the corrosion products, which had a synergistic effect on retarding of the diffusion of molten aluminum. Notably, the corrosion resistance of the Fe-Cr-B-Mo alloy, with an 8.3 wt.% Mo addition, was 3.8 times higher than that of H13 steel.

Study on Corrosion Behavior of Al-Zn-In and Al-Zn-Ga Alloys in NaCl Solution

2011 ◽  
Vol 284-286 ◽  
pp. 1701-1704
Author(s):  
Jing Ling Ma ◽  
Jiu Ba Wen ◽  
Gao Lin Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Impedance Spectroscopy ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Nacl Solution ◽  
X Ray ◽  
Inductive Loop ◽  
Capacitive Loop ◽  
Scanning Electron

The corrosion behavior of Al-5Zn-0.03In and Al-5Zn-0.03Ga alloys in 3.5 % NaCl solution has been examined by electrochemical methods, scanning electron microscopy, X-ray microanalysis, electrochemical impedance spectroscopy. The results demonstrate that the alloys differ in the microstructure, corroded morphology and electrochemical properties. For Al-5Zn-0.03In alloy, the precipitates enriched in Al and Zn initiates pitting. For Al-5Zn-0.03Ga alloy, corrosion occurs more uniformly, the corrosion of the alloy occurred via the formation of a surface Ga-Al amalgam alloy. The EIS of Al-5Zn-0.03In alloy contains a capacitive loop and an inductive loop; the inductive loop can be attributed to the presence of the pitting. The EIS of Al-5Zn-0.03Ga alloy contains only a capacitive loop.

Sintering characteristics of Y–Ba–Cu–oxide–Agx superconductors

1999 ◽  
Vol 14 (11) ◽  
pp. 4148-4156 ◽  
Author(s):  
L. C. Pathak ◽  
S. K. Mishra ◽  
D. Bhattacharya ◽  
K. L. Chopra
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Weak Link ◽  
Sintering Atmosphere ◽  
X Ray ◽  
The Matrix ◽  
Apparent Activation Energies ◽  
Sintering Characteristics ◽  
Powder Compacts ◽  
Scanning Electron

The sintering characteristics of Y–Ba–Cu–oxide (YBCO)–Agx (x = 0 to 1.2) using thermomechanical analyzer were systematically investigated to understand the sintering mechanism of the metal superconductor composites. The addition of Ag was observed to lower the sintering temperatures, and the apparent densities of the sintered compacts increased with x from 0 to 0.6. A further increase of x above 0.6 decreased the apparent densities of the sintered compacts. The presence of Ag globules in the YBCO–Ag compacts was observed by scanning electron microscopy and energy dispersive x-ray spectroscopy. The apparent activation energies for sintering of the powder compacts were estimated and observed to vary between 900 to 2000 kJ/mol. The formation of AgOx by absorbing oxygen from YBCO and sintering atmosphere possibly controls the sintering and superconducting behavior. Incorporation of Ag into the matrix modifies the weak-link characteristics from superconductor–insulator– normal–superconductor (S–I–N–S) to superconductor–normal–superconductor (S–N–S) type.

Preparation and Photoluminescent Properties of Polystyrene Encapsulated SrAl2O4:Eu2+,Dy3+ Nanocrystals

2013 ◽  
Vol 538 ◽  
pp. 197-200 ◽  
Author(s):  
Bao Gai Zhai ◽  
Yuan Ming Huang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Properties ◽  
Phase Morphology ◽  
X Ray ◽  
Weight Percentage ◽  
Deep Blue ◽  
The Matrix ◽  
Pl Spectrum ◽  
Scanning Electron

Polystyrene encapsulated phosphors SrAl2O4:Eu2+,Dy3+ were prepared by dispersing the phosphors into the matrix of polystyrene. The phase, morphology and optical properties of the polystyrene encapsulated phosphors were characterized with X-ray diffractometry, scanning electron microscopy and photoluminescence (PL) spectroscopy, respectively. It has been observed that both the PL spectrum and the luminescent color of the polystyrene encapsulated phosphors can be dramatically modified although the phosphorescence of the polystyrene encapsulated phosphors is not affected. Tunable photoluminescent colors from green to deep-blue are expected for the polystyrene encapsulated phosphors by the control of the weight percentage of the phosphors in the composites.

Electrochemical Synthesis, Characterization and Corrosion Properties of POA−MoO42- Coating in 3.5% NaCl

2020 ◽  
Vol 22 (4) ◽  
pp. 263
Author(s):  
Ye.G. Bakhytzhan ◽  
A.M. Argimbayeva ◽  
G.S. Rakhymbay ◽  
R.Dzh. Jumanova ◽  
Kh. Avchukir ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Method ◽  
Steel Grade ◽  
Nacl Solution ◽  
Corrosion Properties ◽  
Adhesion Properties ◽  
Protective Properties ◽  
X Ray ◽  
Scanning Electron

Polyanisidine (POA) and polyanisidine-molybdate (POA−MoO42-) coatings have been successfully synthesized on steel grade СТ3 from aqueous solutions of oxalic acid by electrochemical method using cyclic voltammetry. The morphology and composition of these films were characterized by scanning electron microscopy (SEM) and energydispersive X-ray (EDAX) methods. It was proven that the introduction of MoO42- into the polyanisidine matrix raised the corrosion resistance of the POA coating and also improved its adhesion properties. The protective properties of steel grade CT3 with POA and POA-MoO42- films were studied using potentiodynamic polarization in 3.5% NaCl solution. The results showed that ions improve anti-corrosion properties of POA films.

scholarly journals Joining of γ-TiAl Alloy to Ni-Based Superalloy Using Ag-Cu Sputtered Coated Ti Brazing Filler Foil

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 723 ◽  
Author(s):  
Sónia Simões ◽  
Carlos Tavares ◽  
Aníbal Guedes
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Tial Alloy ◽  
Energy Dispersive ◽  
X Ray ◽  
Base Materials ◽  
Intermetallic Particles ◽  
Scanning Electron

Joining γ-TiAl alloy to Ni-based superalloy Hastelloy using Ag-Cu sputtered coated Ti foil as brazing filler was investigated in this study. Brazing experiments were performed at 900, 950, and 980 °C with a dwelling stage of 10 min in vacuum. The microstructure and the chemical composition of the resulting interfaces were analyzed by scanning electron microscopy (SEM) and by energy dispersive X-ray spectroscopy (EDS), respectively. Sound joints were produced after brazing at 980 °C, presenting a multilayered interface, consisting mainly of Ti-Al and Ti-Ni-Al intermetallics close to the γ-TiAl alloy, and of Ti-rich, Ti-Ni, and Cr-Ni-Mo rich phases near Hastelloy. The hardness of the interface, ranging from around 300 to 1100 HV0.01, is higher than both base materials, but no segregation of either Ag solid solution or coarse intermetallic particles was observed. Therefore, the developed brazing filler also avoids the need to perform post-brazing heat treatments that aim to eliminate detrimental extensive segregation of either soft phases or of hard and brittle compounds.

scholarly journals Magnetic nanowires (Fe, Fe-Co, Fe-Ni) – magnetic moment reorientation in respect of wires composition

Nukleonika ◽  
2015 ◽  
Vol 60 (1) ◽  
pp. 63-67 ◽  
Author(s):  
Beata Kalska-Szostko ◽  
Urszula Wykowska ◽  
Dariusz Satuła
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Strong Dependence ◽  
Magnetic Nanowires ◽  
Deposition Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ni Alloy ◽  
The Matrix ◽  
Scanning Electron

Abstract Magnetic nanowires of Fe, Fe-Co, and Fe-Ni alloy and layered structure were prepared by electrochemical alternating current (AC) deposition method. The morphology of the nanowires in and without the matrix was studied by energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD), respectively. The wires either show strong dependence on the combination of elements deposition (alloy or layered) or chemical composition (Co or Ni). The magnetic properties of the nanostructures were determined on the basis of Mössbauer spectroscopy (MS).

Effect of Ca on Microstructure and Properties of Mg-Al-Si Alloys

2011 ◽  
Vol 194-196 ◽  
pp. 1369-1373 ◽  
Author(s):  
Chun Xiang Xu ◽  
Hui Ju ◽  
Yang Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Chinese Script ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ca Addition ◽  
The Matrix ◽  
Morphology Modification ◽  
Scanning Electron

Effect of Ca addition on the morphology modification in Mg-7Al-0.8Zn-0.2Mn-1Si (AS71) alloys has been investigated using X-ray diffraction (XRD), optical microscopy (OM), and scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and various testing machines. The results show that when adding 0.1 wt% Ca, a small fraction of Mg2Si change from Chinese script type to polygonal type; with the Ca addition up to 0.3 wt%, edges and angles of polygonal type Mg2Si phase are changed; further increase in Ca addition, the morphology of Mg2Si is changed to strip-like or spot-like one. Meanwhile, the addition of Ca results in the morphology of β- Mg17Al12 phase changing from discontinuous net-like to dispersive island-like. Ca exists as solid-soluting atomic in the matrix with small Ca addition while in the form of CaSi2 with large Ca addition. Optimal mechanical properties can be achieved when Ca addition is 0.3 wt%.

scholarly journals ANALYSES OF WASTE PRODUCTS OBTAINED BY LASER CUTTING OF AW-3103 ALUMINIUM ALLOY

2020 ◽  
Vol 60 (6) ◽  
Author(s):  
Jan Loskot ◽  
Maciej Zubko ◽  
Zbigniew Janikowski
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Composition ◽  
Aluminium Alloy ◽  
Energy Dispersive ◽  
Pure Aluminium ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

In the presented research, the methods of scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and transmission electron microscopy were applied to analyse the powder waste obtained by cutting of AW-3103 aluminium alloy using a fibre laser. The scanning electron microscopy allows to analyse the morphology of the waste microparticles, the energy-dispersive X-ray spectroscopy revealed their chemical composition, which was compared with the composition of the original cut material. In the waste powder, mainly plate-like particles were observed that contain almost pure aluminium. X-ray powder diffraction measurements confirmed that the waste powder is composed of aluminium phase with only a slight presence of other phases (magnetite, austenite and graphite) and the transmission electron microscopy revealed the presence of nanoscale particles in this waste powder. Furthermore, it was found that the average size of the microparticles depends on the thickness of the cut material: particles obtained from a thicker workpiece were substantially bigger than those obtained from the thinner material. On the contrary, the dimensions of the workpiece have only a little impact on the particles’ shape and no significant influence on their chemical composition. The results also suggest that the microparticles could be used as an input material for powder metallurgy. But there is also a certain health risk connected with inhalation of such tiny particles, especially the nanoparticles, which can penetrate deep into the human pulmonary system.

Sign in / Sign up

Export Citation Format

Share Document