Study on the Machined Surface Topography and Performances on Electrochemical Finishing

2005 ◽  
Vol 291-292 ◽  
pp. 579-584
Author(s):  
H.Y. Li ◽  
Xiao Mei Liu ◽  
H.J. Liu ◽  
Jian Cheng Fang
Keyword(s):  
Corrosion Resistance ◽  
Fatigue Strength ◽  
Surface Topography ◽  
Contact Stiffness ◽  
Machined Surface ◽  
Wear And Tear ◽  
Mechanical Performances ◽  
Electrochemical Finishing

In this paper, electrochemical finishing（ECF） is presented. Compared with conventional finishing technology, the characterization of surface topography machined by ECF and its effect on the performance, including friction coefficient, original wear and tear, precision durability, fatigue strength, contact stiffness, corrosion resistance and adhesiveness are analyzed and studied. Experimental results have testified that ECF can observably improve surface quality of parts and finally improve its physical mechanical performances and lifetime to a large extent.

A normal contact stiffness model of machined joint surfaces considering elastic, elasto-plastic and plastic factors

2019 ◽  
Vol 234 (7) ◽  
pp. 1007-1016 ◽  
Author(s):  
Yongquan Zhang ◽  
Hong Lu ◽  
Xinbao Zhang ◽  
He Ling ◽  
Wei Fan ◽  
...  
Keyword(s):  
Surface Topography ◽  
Contact Stiffness ◽  
Fractal Theory ◽  
Fractal Model ◽  
Single Pair ◽  
Machined Surface ◽  
Normal Contact ◽  
Joint Surfaces ◽  
Stiffness Model ◽  
Normal Contact Stiffness

Considering the rough surface as a fractal model makes the research of contact parameters more practical. In the fractal model of the machined surface, the parameters describing the surface topography are independent of the measurement resolution. Based on the elastic, elasto-plastic and plastic deformations of a single pair of contact asperities, a normal contact stiffness model using the fractal model for surface topography description is proposed in this paper. The specimens machined by milling and grinding methods are used to verify the proposed contact stiffness model based on the fractal theory. The experimental and theoretical results indicate that the proposed contact stiffness model is appropriate for the machined joint surfaces.

scholarly journals Characterization of Machined Surface Topography Based on the Normal Declination Angle of Microfacets

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 228
Author(s):  
Wei-Chao Shi ◽  
Jian-Ming Zheng ◽  
Qi-Long Wang ◽  
Li-Jie Wang ◽  
Qi Li
Keyword(s):  
Error Analysis ◽  
Surface Topography ◽  
Lognormal Distribution ◽  
Surface Characteristics ◽  
Mean Square ◽  
Machined Surface ◽  
Characterization Model ◽  
Declination Angle ◽  
Mean Square Errors

It is important to characterize surface topography in order to study machined surface characteristics. Due to the features of periodicity and randomness of machined surface topography, the existing topographical parameters may not describe its features accurately. A novel characterization method called the normal declination angle of microfacet-based surface topography is thus proposed for this task. The topography of machined surfaces is measured and the data on the normal declination angle are obtained. Then, surface topography is analyzed via the distribution of the normal declination angle. The lognormal distribution characterization model of machined surface topography is established, and the accuracy of the model is verified by error analysis. The results show that the calculated results of the present characterization model are generally consistent with the distribution of the normal declination angle, where the maximal root mean square errors (RMSE) is 4.5%. Therefore, this study may serve as an effective and novel way to describe the characteristics of the machined surface topography.

Characterization of Topography of Cut Surface Based on Theoretical Roughness Indexes

2011 ◽  
Vol 496 ◽  
pp. 194-199 ◽  
Author(s):  
Csaba Felhő ◽  
János Kundrák
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Tribological Properties ◽  
Significant Influence ◽  
Machined Surface ◽  
Edge Geometry ◽  
Mathematical Relation ◽  
Cut Surface

The microgeometry of cut surfaces is one important characteristic of surface quality, since it has significant influence on the tribological properties of working surfaces. In addition to the ability to plan the economical effectiveness of cutting and the accuracy of workpieces the ability to plan the quality of machined surfaces has also emphasized importance. This is why the predictability of surface roughness in planning of technological processes is more and more important. More and more opportunities presenting themselves and one of these is the estimation of the expected value of roughness of the machined surface on the basis of the theoretical value of roughness. The paper focuses on the introduction of a method to describe a mathematical relation between the theoretical and the measured roughness indexes in cutting with tools having defined edge geometry, thus the planning may be more accurate.

Research on Grinding Residual Stresses on the Surface of Nanostructured Ceramic Coatings

2013 ◽  
Vol 709 ◽  
pp. 131-134
Author(s):  
Wei Xiang Liu ◽  
Zhong Yu Zhou
Keyword(s):  
Residual Stress ◽  
Corrosion Resistance ◽  
Fatigue Strength ◽  
Service Life ◽  
Residual Stresses ◽  
Ceramic Coatings ◽  
Grinding Process ◽  
Abrasive Wheel ◽  
Nanostructured Ceramic

Residual stress produced on the surface of nanostructured ceramic coatings when they were grinded by diamond superhard abrasive wheel, these residual stresses affected directly the fracture strength, fatigue strength and corrosion resistance of the ceramic parts, they affected the surface quality of machined ceramic parts, and thus they affected the working reliability and the service life of ceramic parts. The tests show that the distribution of residual stress is directional, the residual compressive stress can make the hardness of the material increase, they can reduce the wear rate of the material, for the tested specimen, grinding surface whole residual stress σ is the sum up original residual stress σ0(existed in the part’s surface ) and grinding residual stress Δσ (formed by grinding process.), σ=σ0+ Δσ.

Simulation of Surface Topography Formed During the Intermittent Turning Processes

1991 ◽  
Vol 113 (2) ◽  
pp. 273-279 ◽  
Author(s):  
G. M. Zhang ◽  
S. Yerramareddy ◽  
S. M. Lee ◽  
S. C.-Y. Lu
Keyword(s):  
Surface Topography ◽  
Quantitative Estimate ◽  
Qualitative Evaluation ◽  
Turning Process ◽  
Machined Surface ◽  
Workpiece Surface ◽  
Vibratory Motion ◽  
Intermittent Turning ◽  
Geometric Motion

This paper presents a methodology which employs computer simulation to dynamically generate the topography of a surface machined during an intermittent turning process. The methodology is based on a mathematical model that characterizes the intermittent turning process as an alternating sequence of forced and free vibratory motion. The simulation of machining workpieces, with discontinuous geometries of arbitrary shape, is facilitated by representing the workpiece surface as a two-dimensional grid, with an index for each cell in the grid accounting for the feature boundaries. The tool vibratory motion is integrated with the tool geometric motion to form a basis for the construction of surface texture produced during machining. The simulation model not only provides for a qualitative evaluation of the surface accuracy through a graphic visualization of the surface topography, but also provides a quantitative estimate of the roughness quality of the machined surface.

Physicochemical and bacteriological characterization of hospital effluents and their impact on the environment

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Human Health ◽  
Fecal Coliforms ◽  
Chemical Pollution ◽  
Hospital Effluents ◽  
Biological Contaminants ◽  
Almost All ◽  
Direct Discharge ◽  
Significant Chemical

Liquid effluents discharged by hospitals may contain chemical and biological contaminants whose main source is the different substances used for the treatment of patients. This type of rejection can present a sanitary potentially dangerous risk for human health and can provoke a strong degradation of diverse environmental compartments mainly water and soils. The present study focuses on the quality of the liquid effluents of Hassani Abdelkader’s hospital of Sidi Bel-Abbes (West of Algeria). The results reveal a significant chemical pollution (COD: 879 mgO2/L, BOD5: 850 mgO2/L, NH4+ : 47.9 mg/l, NO2- : 4.2 mg/l, NO3- : 56.8 mg/l with respect to WHO standard of 90 mgO2/L, 30 mgO2/L, 0.5 mg/l, 1 mg/l and 1 mg/l respectively). However, these effluents are biodegradable since the ratio COD/BOD5 do not exceeded the value of 2 in almost all samples. The presence of pathogen germs is put into evidence such as pseudomonas, the clostridium, the staphylococcus, the fecal coliforms and fecal streptococcus. These results show that the direct discharge of these effluents constitutes a major threat to human health and the environment.

ALCOA 2024

Alloy Digest ◽  
1998 ◽  
Vol 47 (3) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Surface Finish ◽  
High Strength ◽  
Machined Surface ◽  
2024 Alloy ◽  
Structural Applications ◽  
Strength Material

Abstract Alcoa 2024 alloy has good machinability and machined surface finish capability, and is a high-strength material of adequate workability. It has largely superseded alloy 2017 (see Alloy Digest Al-58, August 1974) for structural applications. The alloy has comparable strength to some mild steels. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as machining and surface treatment. Filing Code: AL-346. Producer or source: ALCOA Wire, Rod & Bar Division.

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