Effective Damage Indicator for Aluminum Alloy (AA6082Zr) Processed by ECAE

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
M.A. Agwa ◽  
M.N. Ali
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Equal Channel Angular Extrusion ◽  
Lower Surface ◽  
Explicit Model ◽  
Damage Factor ◽  
Channel Angle ◽  
Matlab Code ◽  
Optimum Parameters ◽  
Damage Indicator

The present research aims to study the influence of equal channel angular extrusion (ECAE) parameters (die channel angle, die corner angle, and friction coefficient) on cracking and fracture tendency. For this type of analysis, a MATLAB code integrated with finite element Abaqus/Explicit model was developed and used. A parametric study is done to investigate how the damage tendency varies with changes of ECAE parameters. The distribution of the damage factor based on Cockcroft–Latham equation for different channel angles, corner angles, and friction coefficients is depicted. It is observed that the appearance of cracks on the upper surface is more likely to occur than on the lower surface. The reduction in friction coefficient does not guarantee minimum damage tendency. Finally, the optimum parameters for reducing the fracture tendency in ECAE are presented.

scholarly journals Equal Channel Angular Extrusion Simulation of High-Nb Containingβ-γTiAl Alloys

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Lai-qi Zhang ◽  
Xiang-ling Ma ◽  
Geng-wu Ge ◽  
Yong-ming Hou ◽  
Jun-zi Zheng ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Equal Channel Angular Extrusion ◽  
Effective Strain ◽  
Damage Factor ◽  
Tial Alloys ◽  
Structural Applications ◽  
Angular Extrusion ◽  
Distribution Uniformity ◽  
3D Software ◽  
Deform 3D

TiAl alloys containing high Nb are significantly promising for high-temperature structural applications in aerospace and automotive industries. Unfortunately the low plasticity at room temperature limits their extensive applications. To improve the plasticity, not only optimizing the opposition, but also refining grain size through equal channel angular extrusion (ECAE) is necessary. The equal channel angular extrusion simulation of Ti-44Al-8Nb-(Cr,Mn,B,Y)(at%) alloy was investigated by using the Deform-3D software. The influences of friction coefficient, extrusion velocity, and different channel angles on effective strain, damage factor, and the load on the die were analyzed. The results indicate that, with the increasing of friction coefficient, effective strain is enhanced. The extrusion velocity has little effect on the uniformity of effective strain; in contrast it has large influence on the damage factor. Thus smaller extrusion rate is more appropriate. Under the condition of different channel angles, the larger one results in the lower effective strain magnitude and better strain distribution uniformity.

scholarly journals A Simple Mechanistic Model for Friction of Rough Partially Lubricated Surfaces

2021 ◽  
Vol 69 (3) ◽  
Author(s):  
Gianluca Costagliola ◽  
Tobias Brink ◽  
Julie Richard ◽  
Christian Leppin ◽  
Aude Despois ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Mechanistic Model ◽  
Applied Pressure ◽  
Real Contact Area ◽  
Experimental Measurements ◽  
Dynamic Friction ◽  
Real Contact ◽  
Dynamic Friction Coefficient ◽  
Direct Measurements

AbstractWe report experimental measurements of friction between an aluminum alloy sliding over steel with various lubricant densities. Using the topography scans of the surfaces as input, we calculate the real contact area using the boundary element method and the dynamic friction coefficient by means of a simple mechanistic model. Partial lubrication of the surfaces is accounted for by a random deposition model of oil droplets. Our approach reproduces the qualitative trends of a decrease of the macroscopic friction coefficient with applied pressure, due to a larger fraction of the micro-contacts being lubricated for larger loads. This approach relates direct measurements of surface topography to realistic distributions of lubricant, suggesting possible model extensions towards quantitative predictions.

scholarly journals Influence of load and reinforcement content on selected tribological properties of Al/SiC/Gr hybrid composites

2018 ◽  
Vol 18 (18) ◽  
pp. 18-23 ◽  
Author(s):  
Sandra Veličković ◽  
Slavica Miladinović ◽  
Blaža Stojanović ◽  
Ružica R. Nikolić ◽  
Branislav Hadzima ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Metal Matrix ◽  
Hybrid Composites ◽  
Tribological Characteristics ◽  
Volume Fractions ◽  
Sic Particles ◽  
The Matrix

Abstract Hybrid materials with the metal matrix are important engineering materials due to their outstanding mechanical and tribological properties. Here are presented selected tribological properties of the hybrid composites with the matrix made of aluminum alloy and reinforced by the silicon carbide and graphite particles. The tribological characteristics of such materials are superior to characteristics of the matrix – the aluminum alloy, as well as to characteristics of the classical metal-matrix composites with a single reinforcing material. Those characteristics depend on the volume fractions of the reinforcing components, sizes of the reinforcing particles, as well as on the fabrication process of the hybrid composites. The considered tribological characteristics are the friction coefficient and the wear rate as functions of the load levels and the volume fractions of the graphite and the SiC particles. The wear rate increases with increase of the load and the Gr particles content and with reduction of the SiC particles content. The friction coefficient increases with the load, as well as with the SiC particles content increase.

Effect of ultrasonic melt treatment on the tribological behavior of 7075 aluminum alloy

2020 ◽  
Vol 62 (12) ◽  
pp. 1243-1250
Author(s):  
Fahri Vatansever ◽  
Alpay Tamer Erturk ◽  
Erol Feyzullahoglu
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Tribological Properties ◽  
Lower Surface ◽  
Test Method ◽  
Ring Test ◽  
7075 Aluminum Alloy ◽  
Melt Treatment ◽  
Ultrasonic Melt Treatment ◽  
Worn Surfaces

Abstract In this study, the tribological properties of 7075 aluminum alloy produced by ultrasonic melt treatment (UST) are investigated. Tribological properties of untreated and ultrasonically treated samples under dry and lubricated sliding conditions were analyzed experimentally by the block on ring test method. Worn surfaces of untreated and ultrasonically treated samples were scanned by 3D optical profilometer and analyzed to search out wear characteristics in the material. Furthermore, microstructural examinations were conducted to investigate the beneficial effects of UST on the microstructural properties of the alloy using optical and scanning electron microscopy. According to the results obtained, UST refines the α-Al phase of the alloy and disperses precipitates to grain boundaries more uniformly. Also, hardness and density of the alloy increased through the effect of UST. Due to these favorable effects, the wear resistance of the alloy increased and the worn surfaces of the ultrasonically treated samples exhibited lower surface roughness according to 3D surface roughness measurements.

scholarly journals Friction and Structural Responses of Ion Implanted Polyoxymethylene Copolymer (POM-C)

2016 ◽  
Vol 44 ◽  
pp. 37-44
Author(s):  
Md. Shahinur Rahman ◽  
Konstantin Lyakhov ◽  
Jong-Keun Yang ◽  
Muhammad Athar Uddin ◽  
Muhammad Sifatul Alam Chowdhury
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Surface Deformation ◽  
Ion Beam ◽  
Polymer Surface ◽  
Surface Texturing ◽  
Structural Response ◽  
Lower Surface ◽  
Chain Scission ◽  
Ion Implanted

Polyoxymethylene copolymer (POM-C) round block was implanted with 120 KeV ions of He to doses of 5 x 1016 and 1 x 1016 ions cm-2. It was also implanted with 120 KeV ions of Ar + He and He + Ne to dose of 1 x 1016 ions cm-2, respectively. The friction coefficient behavior of both implanted and unimplanted POM-C blocks was investigated using a ball on disk tribometer mechanism. The friction coefficient of He ion implanted POM-C block at a dose of 5 x 1016 ions cm-2 is lowest compared to all unimplanted and others ions doses implanted POM-C blocks. It also shows the moderate surface texturing (atomic rearrangement), lower surface micro-hardness and average surface roughness compared to both unimplanted and other ions doses implanted POM-C blocks due to well adjusted carbonization, cross-linking and ions-target atoms collisions, which is ascertained from SEM-EDS, Raman spectroscopic and surface profiling observations. The other ions doses implanted POM-C blocks demonstrate the higher friction coefficient and surface roughness with polymer surface deformation (crazing, cracking, pitting and gas evolution, bond breaking) due to severe chain scission, surface dose delivered atomic displacements and chemical structural degradation. It is concluded that the variation in friction coefficient behavior of POM-C block resulted from its structural response for ion beam implantation on the top surface.

Numerical Simulation of Al 6062 Alloy Deformation Behavior Using Equal Channel Angular Extrusion Process with Different Die Angles

2015 ◽  
Vol 813-814 ◽  
pp. 557-562
Author(s):  
Aitha Lavanya ◽  
Perumalla Janaki Ramulu ◽  
G. Sreekanth Kumar ◽  
P. Ramya Sree ◽  
Sirish Battacharya ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Metal Forming ◽  
Equal Channel Angular Extrusion ◽  
Frictional Coefficient ◽  
Maximum Load ◽  
Extrusion Process ◽  
Outer Corner ◽  
Cylindrical Billet ◽  
Angular Extrusion ◽  
Simulation Results

The equal channel angular extrusion (ECAE) is one of the most important methods used for bulk metal forming. In which die angles are the most importent parameter. This paper attempts to determine the effect of different die angles during ECAE process for 6062 aluminum alloy deformation. Numerical simulations are performed for ECAE process on cylindrical billet of 6062 aluminum alloy at a constant frictional coefficient (μ) of 0.08 and punch speed of 15 mm/sec. Die has made with inner corner angles of (φ) =105°, 115°, 125°and 135° by fixing the outer corner angle (ψ) of 6°, punch is designed with a radii (R) of 4.75mm and height of 50mm. From the simulation results, tha data has been obtained in the form of load stroke behavior, and energy consumend during the punch stoke. It is observed that the maximum load and more energy consumption during the process is noted for lower angle.

Wear Behavior of Mg Alloy Procduced by Equal Channel Angular Extrusion

2013 ◽  
Vol 734-737 ◽  
pp. 2369-2372
Author(s):  
Lei Lei Gao ◽  
Jin Zhong Zhang
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Equal Channel Angular Extrusion ◽  
Wear Behavior ◽  
Experimental Results ◽  
Mg Alloy ◽  
Mechanical And Tribological Properties ◽  
Angular Extrusion

A commercial Mg alloy was prepared through equal channel angular extrusion (ECAE) process. The effect of ECAE on mechanical and tribological properties of the alloy was investigated. Experimental results showed that the hardness and strength of the alloy with ECAE were higher than that of the alloy without ECAE and increased with the increase pass number. The friction coefficient and wear resistance of the alloy after ECAE were significantly improved.

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