Tribological Characteristics of Thermomechanically Processed 7075 Al Alloy Through Nano-scratch Characterization

2021 ◽  
pp. 135065012110397
Author(s):  
Souriddha Sanyal ◽  
Ashoktaru Chakraborty ◽  
Angshuman Sarkar ◽  
Susanta K Pradhan ◽  
Utpal Madhu ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Tribological Characteristics ◽  
Temperature Deformation ◽  
Al Alloy ◽  
Thermal Treatments ◽  
Plastic Energy ◽  
Recovery Resistance ◽  
Aa 7075 ◽  
Hardness Values ◽  
Resistance Coefficients

Age-hardenable Al–Zn–Mg–Cu (AA 7075) alloys can be fortified by precipitation solidifying because of precipitation of the MgZn2 intermetallic stages. Furthermore, grain refinement and high dislocation density can also be opted for strengthening purposes. A low-temperature deformation enhances the dislocation density and also facilitates the grains recovery to strengthen the component. The present study combines artificial aging (at 120 °C) and sub-zero (∼−20 ˚C) temperature rolling to achieve strengthening. Various sequences and combinations of these mechanical and thermal treatments are performed and the effects of these treatments on the tribological characteristics of the alloy are studied by nano-scratch measurements. The tribological characteristics are indicated by coefficient of friction ( μ), plastic energy ( PE), recovery index ( η), recovery resistance parameter ( Rs), etc. of each sample. The widths of the scratch are further utilized to calculate the scratch hardness values ( Hs), wear resistance coefficients ( Rw) and the coefficient of wear ( K) with the help of Archard's equation.

scholarly journals Studying the distribution of hardness values in friction drilled 7075 Al-alloy sheets at different conditions

2021 ◽  
Vol 1172 (1) ◽  
pp. 012026
Author(s):  
N Hamzawy ◽  
M Khedr ◽  
T S Mahmoud ◽  
I Ei-Mahallawi ◽  
T A Khalifa
Keyword(s):  
Al Alloy ◽  
7075 Al Alloy ◽  
Hardness Values

Characterization of Cold Sprayed Copper Coatings on Al Alloy Substrate

2015 ◽  
Vol 3 (2) ◽  
pp. 41-53
Author(s):  
Tarun Goyal ◽  
T. S. Sidhu ◽  
R. S. Walia
Keyword(s):  
Spray Deposition ◽  
Structural Characteristics ◽  
Al Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Copper Coatings ◽  
Powder Particles ◽  
Micro Analysis ◽  
Hardness Values

This study reveals the successful low pressure cold spray deposition of near-uniform, defect free and dense copper coatings approximately 700-1900 µm thick, on Al alloy for electro-technical applications. The micro structural characteristics of the deposits have been studied using the combined techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) and electron-probe micro analysis (EPMA). The coatings exhibited characteristic splat-like, layered morphologies due to the deposition of solid powder particles which appeared to have been plastically deformed on impact to the substrate. The developed coatings have a dense (in the range of 3090-5015 kg/m3)and nearly uniform microstructure, with almost uniform hardness values in the range of 120 -140 Hv, and electrical conductivity in the range of 23-30 MS/m. EDAX, XRD and EPMA results revealed that the main constituent in the coating is Cu.

Effects of Dual-Phase Reinforcement Particles (Fly Ash + Al2O3) on the Wear and Tensile Properties of the AA 7075 Al Alloy Based Composites

2019 ◽  
Vol 100 (1) ◽  
pp. 29-35 ◽  
Author(s):  
T. Ram Prabhu ◽  
M. Murugan ◽  
B. P. Chiranth ◽  
R. K. Mishra ◽  
N. Rajini ◽  
...  
Keyword(s):  
Fly Ash ◽  
Tensile Properties ◽  
Al Alloy ◽  
Dual Phase ◽  
7075 Al Alloy ◽  
Aa 7075

Constitutive Modeling of Beta Titanium Alloy Ti-10V-4.5Fe-1.5Al during Hot Deformation Process

2012 ◽  
Vol 510 ◽  
pp. 729-733
Author(s):  
Feng Bo Han ◽  
Jin Shan Li ◽  
Hong Chao Kou ◽  
Bin Tang ◽  
Min Jie Lai ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Dislocation Density ◽  
Internal State ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Model Parameters ◽  
Internal State Variable ◽  
Dislocation Interaction ◽  
State Variable

A constitutive model using dislocation density rate as an internal state variable has been proposed for hot working of β titanium alloy in this paper. The β phase was only taken into consideration during high temperature deformation. The solution strengthening and dislocation interaction were included in the constitutive equations. The strength coefficient was determined by equivalent vanadium content, Veq, which was calculated according to the alloy constituent. A Kocks-Mecking model was adopted to describe the variation of dislocation density. The constitutive relationship of a β titanium alloy Ti-10V-4.5Fe-1.5Al for high temperature deformation was established using the internal-state-variable based model. Model parameters were determined by the genetic algorithm based objective optimization method. The predicted results agree fairly well with the experimental value.

Modelling Dynamic Recovery and Recrystallization of Metals by a New Non-Equilibrium Thermodynamics Approach

2007 ◽  
Vol 558-559 ◽  
pp. 517-522
Author(s):  
Ming Xin Huang ◽  
Pedro E.J. Rivera-Díaz-del-Castillo ◽  
Sybrand van der Zwaag
Keyword(s):  
Steady State ◽  
High Temperature ◽  
Flow Stress ◽  
Dislocation Density ◽  
Dynamic Recovery ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Equilibrium Thermodynamics ◽  
Burgers Vector ◽  
Non Equilibrium

A non-equilibrium thermodynamics-based approach is proposed to predict the dislocation density and flow stress at the steady state of high temperature deformation. For a material undergoing dynamic recovery and recrystallization, it is found that the total dislocation density can be expressed as ( )2 ρ = λε& b , where ε& is the strain rate, b is the magnitude of the Burgers vector and λ is a dynamic recovery and recrystallization related parameter.

Comparison of High-Temperature Compressive Deformation Characteristics of Differently Processed LY12 Aluminum Alloys

2010 ◽  
Vol 667-669 ◽  
pp. 845-849
Author(s):  
Yao Wang ◽  
Qing Wei Jiang ◽  
Ying Wu ◽  
Xiao Wu Li
Keyword(s):  
High Temperature ◽  
Surface Deformation ◽  
Testing Temperature ◽  
Al Alloys ◽  
Compressive Deformation ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Al Alloy ◽  
Damage Characteristics ◽  
Angular Pressing

The individual or joint effects of annealing and equal channel angular pressing (ECAP) treatments on the high-temperature compressive deformation and damage behavior of cast LY12 Al alloys were studied. The compressive deformation behavior and surface deformation and damage characteristics of differently treated LY12 Al alloy samples were examined at temperatures ranging from 25°C to 400°C. It is found that the LY12 Al alloy exhibits different compressive mechanical behavior depending on different treatments, and the compressive deformation and damage characteristics of LY12 Al alloys with different microstructural states are closely related with the testing temperature. As compared to other samples (e.g. as-cast, annealed, as-cast+2ECAPed), the sample annealed at 450°C for 3h followed by ECAPed for 2 passages (i.e. annealed+2ECAPed) shows a better high-temperature deformation stability.

Significance of High Rate Superplasticity in Metallic Materials

1990 ◽  
Vol 196 ◽  
Author(s):  
Norio Furushiro ◽  
Shigenori Hori
Keyword(s):  
Grain Size ◽  
High Strain Rate ◽  
Strain Rate ◽  
Grain Refinement ◽  
Fine Particles ◽  
High Strain ◽  
High Rate ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Al Alloy

ABSTRACTIt has been expected that “High rate superplastic materials” will be developed for industrial applications. The Dorntype equation for high temperature deformation suggests that strain rate can be increased if the grain size is decreased. This means that grain refinement can effectively establish high strain rate superplastic materials.It is well known that a high degree of grain size refinement will result from the addition of zirconium to Al-base alloys. Powder-metallurgical processing with rapidly solidified powders is also available for the improvement of superplasticity by both the refinement of the solidified structure and the maintenance of the stable fine structure of a 7475 Al alloy during recrystallization and deformation. Therefore. P/M 7475 Al alloys containing Zr up to 0.9 wt% were selected as candidate specimens. The objective of the present paper includes the clarification of the role and the effective amount of Zr to obtain high strain rate superplastic materials. As a result, the addition of 0.3%Zr or more is effective in grain refinement of the P/M 7475 Al alloy. However, alloys containing 0.7 and 0.9 wt%Zr only show superplasticity at 793K. The optimum strain rate is shifted to a higher range with increasing Zr. The alloy of 7475 Al-0.9%Zr shows the maximum elongation of 900% at the remarkably high strain rate of 3.3×10−1 s−1.The deformation mechanism of such high stain rate superplasticity will be discussed briefly, by considering the effect of the fine particles of Zr on superplastic behavior.

Tribological characteristics of A356 Al alloy–SiCP composite discs

Wear ◽  
2011 ◽  
Vol 271 (9-10) ◽  
pp. 1946-1950 ◽  
Author(s):  
R.C. Shivamurthy ◽  
M.K. Surappa
Keyword(s):  
Tribological Characteristics ◽  
Al Alloy

scholarly journals The Applicability of Die Cast A356 Alloy to Additive Friction Stir Deposition at Various Feeding Speeds

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6018
Author(s):  
Bandar Alzahrani ◽  
Mohamed M. El-Sayed Seleman ◽  
Mohamed M. Z. Ahmed ◽  
Ebtessam Elfishawy ◽  
Adham M. Z. Ahmed ◽  
...  
Keyword(s):  
Grain Size ◽  
Cast Alloy ◽  
A356 Alloy ◽  
Deposition Process ◽  
Al Alloy ◽  
Cast Material ◽  
Mean Values ◽  
Friction Stir ◽  
Eutectic Si ◽  
Hardness Values

In the current investigation, additive friction stir-deposition (AFS-D) of as-cast hypoeutectic A356 Al alloy was conducted. The effect of feeding speeds of 3, 4, and 5 mm/min at a constant rotational speed of 1200 rpm on the macrostructure, microstructure, and hardness of the additive manufacturing parts (AMPs) was investigated. Various techniques (OM, SEM, and XRD) were used to evaluate grain microstructure, presence phases, and intermetallics for the as-cast material and the AMPs. The results showed that the friction stir deposition technique successfully produced sound additive manufactured parts at all the applied feeding speeds. The friction stir deposition process significantly improved the microstructure of the as-cast alloy by eliminating porosity and refining the dendritic α-Al grains, eutectic Si phase, and the primary Si plates in addition to intermetallic fragmentation. The mean values of the grain size of the produced AMPs at the feeding speeds of 3, 4, and 5 mm/min were 0.62 ± 0.1, 1.54 ± 0.2, and 2.40 ± 0.15 µm, respectively, compared to the grain size value of 30.85 ± 2 for the as-cast alloy. The AMPs exhibited higher hardness values than the as-cast A356 alloy. The as-cast A356 alloy showed highly scattered hardness values between 55 and 75.8 VHN. The AMP fabricated at a 3 mm/min feeding speed exhibited the maximum hardness values between 88 and 98.1 VHN.

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