Theoretical Estimation of The Influence of Plastic Deformation on Average Coefficient of Friction in the Process of Nanostructuring Burnishing of Metal Samples

2019 ◽  
Vol 40 (5) ◽  
pp. 384-391
Author(s):  
I. A. Lyashenko ◽  
V. L. Popov
Keyword(s):  
Plastic Deformation ◽  
Coefficient Of Friction ◽  
Theoretical Estimation ◽  
Average Coefficient ◽  
Nanostructuring Burnishing

Influence of the second-generation adaptive friction clutch configuration method (basic version) for its maximum load

2020 ◽  
pp. 552-557
Author(s):  
M.P. Shishkarev
Keyword(s):  
Safety Factor ◽  
Coefficient Of Friction ◽  
Second Generation ◽  
Maximum Load ◽  
Maximum Torque ◽  
Minimum Value ◽  
Average Coefficient ◽  
Friction Clutch ◽  
The Coefficient Of Friction ◽  
Basic Version

It is shown that the maximum torque of adaptive friction clutches of the second generation (baseline) when it is configured with the minimum coefficient of friction less than the setting based on an average coefficient of friction, if a ratio of the coefficient of friction to its minimum value more than the value of the safety factor.

Tribological Characterization of AZ91 and AE42 Magnesium Alloys in Fretting Contact

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
D. Khabale ◽  
M. F. Wani
Keyword(s):  
Magnesium Alloys ◽  
Coefficient Of Friction ◽  
Normal Load ◽  
Fretting Wear ◽  
Wear Volume ◽  
Dry Sliding ◽  
Running Time ◽  
Average Coefficient ◽  
Tribological Characterization

Fretting wear studies were conducted on AZ91 and AE42 magnesium alloys against steel ball. Average coefficient of friction (COF) remains steady with the increase in running time. However, average coefficient of friction decreases with the increase in normal load and frequency and marginally increases with the increase in amplitude. A constant average coefficient of friction of 0.06 was observed for both AZ91 and AE42 under dry sliding conditions at normal load of 50 N. Wear volume increases linearly with increasing running time. Wear volume first decreases sharply, attains minima, and then increases marginally with the increase in normal load. However, wear volume increases with increasing amplitude and frequency. Higher specific wear rate of 10.5 × 10−6 mm3 N−1·m−1 was observed for AE42, as compared to 4.5 × 10−6 mm3 N−1·m−1 for AZ91. The wear in magnesium alloy was caused by a combination of adhesion, abrasion, oxidation, delamination, and plastic deformation under different fretting conditions.

Plowing Friction Under Harmonic Normal Loads

1999 ◽  
Vol 121 (2) ◽  
pp. 282-285 ◽  
Author(s):  
D. P. Hess
Keyword(s):  
Shear Strength ◽  
Coefficient Of Friction ◽  
Metal Surfaces ◽  
Sliding Friction ◽  
Normal Load ◽  
Hard Materials ◽  
Lubricated Contacts ◽  
Highly Nonlinear ◽  
Average Coefficient ◽  
The Coefficient Of Friction

The influence of harmonic normal loads on sliding friction is investigated through analysis of contacts consisting of conical and spherical sliders of hard materials on softer metal surfaces. Friction for such contacts is assumed to result from a plowing component and a shearing component. Calculations and experiments show that the coefficient of friction is essentially independent of normal load for contacts with conical sliders. However, for spherical sliders the relation between the coefficient of friction and normal load is highly nonlinear. In the presence of harmonic variations in normal load, this non-linearity causes a shift in the average coefficient of friction. For ideal lubricated contacts, the shearing component of friction is very small and for this case, it is shown that the maximum average reduction in the coefficient of friction is ten percent. When the shearing component is more significant, as with dry contacts, the shift is less. For example, when the shear strength is one-sixth the hardness of the softer material, the maximum average reduction in the coefficient of friction is five percent.

Cutting Mechanism of Resin Impregnated Sintered Iron

2010 ◽  
Vol 638-642 ◽  
pp. 1836-1841 ◽  
Author(s):  
Kunio Okimoto
Keyword(s):  
Plastic Deformation ◽  
Thermal Properties ◽  
Flow Stress ◽  
Cutting Force ◽  
Coefficient Of Friction ◽  
Work Hardening ◽  
Fracture Strain ◽  
Cutting Mechanism ◽  
Sintered Iron ◽  
Resin Impregnation

Impregnating resin into the open pores of a sintered iron compact is well known to improve the machinability of the compact. However, the causes of this phenomenon require further investigation. The purpose of this study is to clarify the main cause of the improvement in machinability on resin impregnation. In this study, sintered iron was machined and the influences of resin impregnation on its thermal properties, coefficient of friction, and flow stress (deformation resistance) were investigated. The results indicate that the great improvement in machinability produced by resin impregnation is mainly due to a reduction in the plastic deformation (fracture strain) for chip generation, lowering the degree of work hardening and consequently reducing the cutting force required.

Plowing Friction in Dry and Lubricated Metal Sliding

1986 ◽  
Vol 108 (3) ◽  
pp. 301-312 ◽  
Author(s):  
K. Komvopoulos ◽  
N. Saka ◽  
N. P. Suh
Keyword(s):  
Plastic Deformation ◽  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Interfacial Friction ◽  
Dry Sliding ◽  
The Coefficient Of Friction ◽  
Analytical Expressions ◽  
Cutting Experiments ◽  
Theory And Experiment ◽  
Lubricated Sliding

Experimental evidence for plowing under dry and lubricated sliding conditions is presented and analytical expressions for the coefficient of friction due to plowing are obtained. The theoretical friction coefficient was found to be a function of the sharpness of the hard asperities, the interfacial “friction” conditions and the shape of the plastic zone. The agreement between theoretical and experimental friction coefficients from lubricated sliding and cutting experiments was remarkably good. The discrepancy between theory and experiment in the case of dry sliding between like metals was shown to be due to plastic deformation of the asperities. Consequently, a different model for plowing was proposed for the case of dry sliding between like metals which produced estimates for the coefficient of friction in fair agreement with the experimental results.

scholarly journals Wear Behavior of a Heat-Treatable Al-3.5Cu-1.5 Mg-1Si Alloy Manufactured by Selective Laser Melting

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7048
Author(s):  
Pei Wang ◽  
Yang Lei ◽  
Jun-Fang Qi ◽  
Si-Jie Yu ◽  
Rossitza Setchi ◽  
...  
Keyword(s):  
Wear Rate ◽  
Selective Laser Melting ◽  
Coefficient Of Friction ◽  
Mechanical Performance ◽  
Wear Behavior ◽  
Secondary Phase ◽  
Specific Wear Rate ◽  
Laser Melting ◽  
Heat Treated ◽  
Average Coefficient

In this study, the wear behavior of a heat-treatable Al-7Si-0.5Mg-0.5Cu alloy fabricated by selective laser melting was investigated systematically. Compared with the commercial homogenized AA2024 alloy, the fine secondary phase of the SLM Al-Cu-Mg-Si alloy leads to a low specific wear rate (1.8 ± 0.11 × 10−4 mm3(Nm)−1) and a low average coefficient of friction (0.40 ± 0.01). After the T6 heat treatment, the SLM Al-Cu-Mg-Si alloy exhibits a lower specific wear rate (1.48 ± 0.02 × 10−4 mm3(Nm)−1), but a similar average coefficient of friction (0.34 ± 0.01) as the heat-treated AA2024 alloy. Altogether, the SLM Al-3.5Cu-1.5 Mg-1Si alloy is suitable for the achievement of not only superior mechanical performance, but also improved tribological properties.

Effect of Pad Surface Texture and Slurry Abrasive Concentration on Tribological and Kinetic Attributes of ILD CMP

2003 ◽  
Vol 767 ◽  
Author(s):  
Ara Philipossian ◽  
Scott Olsen
Keyword(s):  
Coefficient Of Friction ◽  
Surface Texture ◽  
Material Removal ◽  
Hydrodynamic Lubrication ◽  
Removal Rate ◽  
Two Phase ◽  
Lubrication Regimes ◽  
Time Coefficient ◽  
Wide Range ◽  
Average Coefficient

AbstractReal-time coefficient of friction (COF) analysis is used to determine the extent of normal and shear forces during CMP and identify the lubrication regimes associated with the process. Pads with different surface textures and slurries with varying abrasive concentrations are used to polish ILD films over a wide range of operating parameters. Results show that by varying abrasive concentration and pad surface texture, one can cause the process tribology to change from ‘boundary lubrication’ to ‘partial lubrication’, to ‘hydrodynamic lubrication’. A two-phase model relating average coefficient of friction and Preston's constant is presented. At abrasive concentrations up to 9 percent, material removal is proportional to the extent of contact between the abrasives and the wafer. At abrasive concentrations between 9 to 25 percent, removal rate is directly influenced by average COF. A new parameter termed the ‘tribological mechanism indicator’ is defined and extracted from the data, which coupled with the information on COF and ILD removal rate, results in a series of ‘universal’ correlations. A qualitative model based on pad storage modulus is used to explain the trends.

scholarly journals Design Optimization of Angular Extrusion for Severe Plastic Deformation of Tubular Specimens

2017 ◽  
Author(s):  
Madaraka Fredrick Mwema ◽  
Kiptoo Matthew ◽  
Shagwira Harisson ◽  
Obiko Japheth
Keyword(s):  
Plastic Deformation ◽  
Coefficient Of Friction ◽  
Load Distribution ◽  
Element Model ◽  
Extrusion Dies ◽  
Angular Extrusion ◽  
Deformation Ratio ◽  
Sever Plastic Deformation ◽  
Tubular Specimens ◽  
Deform 3D

The purpose of this work is to optimize angular extrusion for sever plastic deformation of tubular specimens. A finite element model (FEM) was built in Deform-3D® for three extrusion dies and analyzed. The dies were ECAP (135°), TCAP with external groove of 90° (denoted as TCAP-e) and TCAP with internal groove of 90° (denoted as TCAP-i). The analysis for process parameters (such as coefficient of friction-μ, die angles-ѱ and φ, temperature - T, and radius ratio-R) showed that TCAP-i was the optimal die in processing Al6063 tubes based on strain and load distribution of the model. The TCAP-i die model was further optimized for different parameters namely die angles, coefficient of friction, deformation ratio and temperature. The results showed that at constant process temperature of 25 °C, the optimal TCAP-i has the following parameters: φ2=800, Ѱ1=300, Ѱ2=800, Ѱ3=300, μ =0.4 and R =1.5.

Modeling and Optimization of Friction and Wear Characteristics of Ti3Al2.5V Alloy Under Dry Sliding Condition

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Mukund Dutt Sharma ◽  
Rakesh Sehgal ◽  
Mohit Pant
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Friction And Wear ◽  
Experimental Results ◽  
Contact Temperature ◽  
Dry Sliding ◽  
Sliding Velocity ◽  
Average Coefficient ◽  
Maximum Contact ◽  
Friction And Wear Characteristics

Modeling of dry sliding friction and wear behavior of Ti3Al2.5V alloy sliding against EN31 steel using a multi-tribotester has been presented. Mathematical model equations in the form of natural log transformation for wear rate (WR), average coefficient of friction (μa), and a square root transformation for maximum contact temperature (Tm) considering the effect of tribological variables have been developed and validated by comparing them with the experimental results. The authors claim novelty with regard to modeling and optimization of friction and wear characteristics of Ti-3Al2.5V alloy. The results reveal that the magnitude of wear rate and maximum contact temperature increases with increase in sliding velocity and increasing normal load with few exceptions. Whereas average coefficient of friction first increases with increasing sliding velocity up to 2.51 m/s, and then decreases at highest sliding velocity. The load is found to have strongest influence on both wear rate and average coefficient of friction followed by sliding velocity, whereas sliding velocity has strongest influence on the maximum contact temperature followed by load. The perturbation plot results are also in accordance with the analysis of variance (ANOVA) analysis. The theoretical and experimental results have an average error of 5.06%, 1.78%, and 1.42%, respectively, for wear rate, average coefficient of friction, and maximum contact temperature. Optimization resulted in a maximum desirability of 0.508 at a load of 60 N and a sliding velocity of 1.5 m/s. For these values, the predicted minimum wear rate is 0.0001144 g/m, the coefficient of friction is 0.3181, and the tool-tip temperature is 59.03 °C.

Sign in / Sign up

Export Citation Format

Share Document