Transition Between Severe and Mild Wear of 2024A-T4 Anodized Aluminum Alloy under Severe Wear Conditions

2020 ◽  
Vol 76 (10) ◽  
pp. 899-903
Author(s):  
Nazih Tekkouk ◽  
Mohamed Arbaoui ◽  
Saîd Abdi ◽  
Amine Rezzoug
Keyword(s):  
Aluminum Alloy ◽  
Anodized Aluminum ◽  
Severe Wear ◽  
Mild Wear

Transition of Mild Wear to Severe Wear in Oxidative Wear of H21 Steel

2008 ◽  
Vol 32 (2) ◽  
pp. 67-72 ◽  
Author(s):  
S. Q. Wang ◽  
M. X. Wei ◽  
F. Wang ◽  
X. H. Cui ◽  
C. Dong
Keyword(s):  
Oxidative Wear ◽  
Severe Wear ◽  
Mild Wear

Study on Heat Transfer and Corrosion Resistance of Anodized Aluminum Alloy in Gallium-Based Liquid Metal

2019 ◽  
Vol 141 (1) ◽  
Author(s):  
Yuntao Cui ◽  
Yujie Ding ◽  
Shuo Xu ◽  
Yushu Wang ◽  
Wei Rao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Liquid Metal ◽  
Effective Thermal Conductivity ◽  
Anodic Oxidation ◽  
Convective Heat Transfer Coefficient ◽  
Total Thickness ◽  
Anodized Aluminum

Gallium-based liquid metal (LM) inherits excellent thermophysical properties and pollution-free characteristics. However, it has long been a fatal problem that LM would cause serious corrosion and embrittlement on the classical substrate made of aluminum alloys in constructing chip cooling device. Here, anodic oxidation treatment was introduced on processing the aluminum alloy aiming to tackle the corrosion issues. The prepared anodic oxidation aluminum (AAO) coatings were composed of nanopore layers and barrier layers on a high-purity alumina matrix that were manufactured electrochemically. According to the measurement, the effective thermal conductivity of the anodized aluminum alloy increases with the total thickness of sample increasing. When the total thickness L exceeds 5 × 10−3 m, effects of the porous media on effective thermal conductivity are negligible via model simulation and calculation. It was experimentally found that aluminum alloy after surface anodization treatment presented excellent corrosion resistance and outstanding heat transfer performance even when exposed in eutectic gallium–indium (E-GaIn) LM over 200 °C. The convective heat transfer coefficient of LM for anodized sample reached the peak when the heat load is 33.3 W.

Characterization of 2017A Anodized Aluminum Alloy by Infrared Thermographic Techniques and SEM Observations During Tensile Testing

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
C. Fares ◽  
M. A. Belouchrani ◽  
M. Hadj Meliani ◽  
A. Alhussein ◽  
N. Merah ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Tensile Testing ◽  
Anodized Aluminum

Tribological behaviour of hypereutectic Al-Si automotive cylinder liner material under dry sliding wear condition in severe wear regime

2020 ◽  
pp. 135065012096461
Author(s):  
Ajith Kurian Baby ◽  
M Priyaranjan ◽  
K Deepak Lawrence ◽  
PK Rajendrakumar
Keyword(s):  
Surface Morphology ◽  
Wear Behaviour ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Liner Material ◽  
Severe Wear ◽  
Mild Wear ◽  
The Matrix ◽  
Pin On Disk ◽  
Silicon Particles

Hypereutectic Al-Si alloys are used as material for the engine block and cylinder liners in automobiles. Wear behaviour of hypereutectic Al-Si alloy system changes significantly with applied normal load in both mild wear and severe wear regime. Significant improvement in wear resistance can be obtained by exposing silicon particles through the chemical etching process. For Al-25% Si alloys, most studies are reported in mild and ultra-mild wear regime. In the present work, the wear of exposed silicon particles with varying load and speed in severe wear regime was investigated under the unidirectional sliding condition and bi-directional sliding condition using a pin-on-disk tribometer (POD) and a linear reciprocating tribometer (LRT), respectively. Rapidly solidified and T6 heat-treated Al-25Si alloy was polished and etched using 5% NaOH solution to expose the silicon particles. Experiments were carried out with normal loads varying from 40 N to 120 N in dry sliding conditions. Sliding speeds of 0.8 m/s and 1.5 m/s were applied for each load in case of a pin on disk tribometer whereas, in an LRT, the sliding velocities were 0.2 m/s and 0.45 m/s respectively for each set of the load. The surface topography was measured by means of a 3-D optical profilometer, and surface morphology was analyzed using SEM images. It was observed that at higher loads, larger Si particles were fractured and pushed into the matrix. Fractured silicon particles, along with smaller particles, were embedded into the matrix, thereby increasing the silicon concentration in the wear region. The comparison of the experimental results of unidirectional and bi-directional sliding that reveal the change in surface morphology of silicon particles, the friction characteristics at the interface, variation of surface 3-D roughness parameters, the wear rate and wear mechanisms of Al-25% Si alloys are analyzed and reported in the study.

scholarly journals Low Temperature Sealing of Anodized Aluminum Alloy for Enhancing Corrosion Resistance

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4904
Author(s):  
Hyunbin Jo ◽  
Soomin Lee ◽  
Donghyun Kim ◽  
Junghoon Lee
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Anodic Oxide ◽  
Nickel Acetate ◽  
Anodized Aluminum ◽  
Corrosive Media ◽  
Nickel Fluoride

Sealing as a post treatment of anodized aluminum is required to enhance the corrosion resistance by filling nanopores, which allow the penetration of corrosive media toward the base aluminum. We designed a mixed sealing solution with nickel acetate and ammonium fluoride by modifying traditional nickel fluoride cold sealing. The concentration of mixed sealing solution affected the reaction rate of sealing and corrosion current density of anodized aluminum alloy. The higher concentration of mixed sealing solution improved the sealing rate, which was represented by a decrease of corrosion current density of anodized aluminum alloy. However, a mixed sealing solution with 2/3 concentration of general nickel fluoride sealing solution operated at room temperature showed the lowest corrosion current density compared to traditional methods (e.g., nickel fluoride cold sealing (NFCS) and nickel acetate hot sealing) and other mixed sealing solutions. Moreover, the mixed sealing solution with 2/3 concentration of general NFCS had a lower risk for over sealing, which increases the corrosion current density by excessive dissolution of anodic oxide. Therefore, the mixed sealing solution with optimized conditions designed in this work possibly provides a new method for enhancing the corrosion resistance of anodized aluminum alloys.

The dry wear of steels II. Interpretation and special features

1965 ◽  
Vol 257 (1077) ◽  
pp. 51-70 ◽  
Keyword(s):  
Oxide Film ◽  
Phase Change ◽  
Strain Hardening ◽  
Frictional Heating ◽  
Combined Effects ◽  
Phase Hardening ◽  
Special Effects ◽  
Severe Wear ◽  
Wear Rates ◽  
Mild Wear

The pattern of wear outlined in part I is interpreted in the light of further experiments which reveal that the change from severe wear to mild is governed by the hardness and state of oxidation of the surfaces. At light loads (< T 1) severe wear is inhibited by the combined effects of strain hardening and oxidation. At higher loads (> T 2) mild wear recurs primarily as a consequence of a change of phase induced by frictional heating. The hardness accompanying the phase change is great enough, initially, to suppress severe wear without the intervention of an oxide film. At loads immediately above T 2, however, the hardness tends to fall if rubbing is prolonged and oxidation is again essential to preserve the mild wear state. Sustained phase-hardening does not occur until a higher load, roughly coinciding with the T 3 transition, is attained and this finding has an important bearing on the influence of inert atmospheres. The onset of permanent hardening is not responsible for the divergent pin and ring wear rates at T 3, though the phenomena may be linked by the magnitude of the temperatures required to cause phase-hardening; the T 3 transition and the trend at higher loads have been identified as special effects associated with the thermal asymmetry of the rubbing system.

Emittance of Boehmite and Alumina Films on 6061 Aluminum Alloy Between 295 and 773 K

1991 ◽  
Vol 113 (1) ◽  
pp. 185-189 ◽  
Author(s):  
T. G. Kollie ◽  
T. D. Radcliff ◽  
F. J. Weaver
Keyword(s):  
Aluminum Alloy ◽  
National Laboratory ◽  
X Ray Diffraction ◽  
Anodized Aluminum ◽  
Aluminum Films ◽  
Oak Ridge ◽  
Alumina Films ◽  
Loss Of Coolant Accident ◽  
Total Hemispherical Emittance ◽  
Loss Of Coolant

The total hemispherical emittance of an oxide film that formed on 6061-T6 aluminum alloy parts in the Tower Shielding Reactor-II at Oak Ridge National Laboratory was measured from 295 to 773 K using an emissometer and/or a calorimeter. The emittance of this film was critically needed for heat transfer calculations in a simulated loss-of-coolant accident of the reactor. X-ray diffraction analysis identified the film as boehmite (Al2O3·H2O), which dehydrated to alumina (Al2O3) upon heating above 473 K. The measured emittances for the alumina film are in excellent agreement with published values for anodized aluminum films and for bulk alumina. Published values of the emittance of boehmite could not be found for comparison, but evidence is presented that some anodization processes for aluminum yield boehmite and not alumina films.

Influence of Mechanical and Chemical Factors on Transition Between Severe and Mild Wear in Saline Solution

1997 ◽  
Vol 119 (4) ◽  
pp. 619-625 ◽  
Author(s):  
H. Goto
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Content ◽  
Cathodic Protection ◽  
Saline Solution ◽  
Concentration Level ◽  
Applied Potential ◽  
Severe Wear ◽  
Saturated Condition ◽  
Mild Wear ◽  
Chemical Factors

Pin-on-disk wear tests of carbon steels in saline solution were carried out at high loads to study the effects of mechanical and chemical factors on the transition between severe and mild wear. The factors were load, presliding time, concentration of saline solution, dissolved oxygen content, and applied potential for cathodic protection. Severe wear and seizure appear at low concentration levels of saline solution and the transition takes place at a certain concentration level of saline solution. The concentration level for the transition is higher under argon-saturated condition than under air-saturated condition. Mild wear is predominant over the whole range of dissolved oxygen content from 0.5 to 18 ppm in 0.5 wt percent saline solution and the wear rate decreases with decreasing dissolved oxygen content. The mild wear occurs in the range from 2 to 18 ppm in 0.01 wt percent saline solution, whereas the wear mode moves to severe wear below 2 ppm. Mild wear predominates under incomplete cathodic protection between −0.50 and −0.80 V (versus Ag/AgCl in 0.5 wt percent saline solution. The applied potential for the transition from initial to steady wear is more negative under higher dissolved oxygen content condition. Complete severe wear occurs below −0.90 V (versus Ag/AgCl) with a risk of seizure.

Cr2O3 sealing of anodized aluminum alloy by heat treatment

2014 ◽  
Vol 243 ◽  
pp. 34-38 ◽  
Author(s):  
Junghoon Lee ◽  
Yonghwan Kim ◽  
Heuiun Jang ◽  
Wonsub Chung
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Anodized Aluminum
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