scholarly journals Effect of Lubrication and Forging Load on Surface Roughness, Residual Stress, and Deformation of Cold Forging Tools

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 783
Author(s):  
Karunathilaka ◽  
Tada ◽  
Uemori ◽  
Hanamitsu ◽  
Fujii ◽  
...  
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
High Speed ◽  
Compressive Force ◽  
Cold Forging ◽  
Metallic Contact ◽  
Heat Treated ◽  
Stress Surface ◽  
Stress And Deformation ◽  
Forging Load

Cold forging is a metal forming that which uses localized compressive force at room temperature. During the cold forging process, the tool is subjected to extremely high loads and abrasive wear. Lubrication plays an important role in cold forging to improve product quality and tool life by preventing direct metallic contact. Surface roughness and residual stress also greatly affects the service life of a tool. In this study, variations in surface roughness, residual stress, and specimen deformation with the number of cold forging cycles were investigated under different forging conditions. Specimens that were made of heat-treated SKH51 (59–61 HRC), a high-speed tool steel with a polished working surface, were used. The specimens were subjected to an upsetting process. Compressive residual stress, surface roughness, and specimen deformation showed a positive relationship with the number of forging cycles up to a certain limit and became almost constant in most of the forging conditions. A larger change in residual stress and surface roughness was observed at the center of the specimens in all the forging conditions. The effect of the magnitude of the forging load on the above discussed parameters is large when compared to the effect of the lubrication conditions.

A Study on the Fatigue Characteristics of Al6061-T651 by Shot Peening Velocity

2006 ◽  
Vol 326-328 ◽  
pp. 1093-1096 ◽  
Author(s):  
Won Jo Park ◽  
Sun Chul Huh ◽  
Sung Ho Park
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Fatigue Life ◽  
Shot Peening ◽  
High Speed ◽  
Compressive Residual Stress ◽  
Velocity Increase ◽  
Fatigue Characteristics ◽  
Height Increase ◽  
Small Steel

Small steel ball is utilized in Shot peening process. Called “shot ball” are shot in high speed on the surface of metal. When the shot ball hit the surface, it makes plastic deformation and bounce off, that increase the fatigue life by compressive residual stress on surface. In this study, the results of observation on the tensile strength, hardness, surface roughness, compressive residual stress and fatigue life of a shot peened Al6061-T651 were obtained. Experimental results show that arc height increase tremendously by shot velocity. Also, it shows that surface roughness, hardness, compressive residual stress and fatigue life increase as shot velocity increase.

Effects of different shot peening parameters on residual stress, surface roughness and cell size

2020 ◽  
Vol 398 ◽  
pp. 126054 ◽  
Author(s):  
Qinjie Lin ◽  
Huaiju Liu ◽  
Caichao Zhu ◽  
Difa Chen ◽  
Shuangshuang Zhou
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Cell Size ◽  
Shot Peening ◽  
Stress Surface

Effect of Surface Roughness and Residual Stress Induced by High Speed Milling Process on Short Crack Growth

2016 ◽  
Author(s):  
B. Zheng ◽  
H. D. Yu ◽  
X. Wang ◽  
X. M. Lai
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Residual Stresses ◽  
Crack Growth ◽  
Damage Evolution ◽  
High Speed ◽  
Milling Process ◽  
Short Crack ◽  
Machining Process ◽  
Effect Of Surface

Surface scratches and residual stresses inevitably appear on the surface of the component as a result of the machining process. The damage evolution of surface scratch due to the combined effect of cyclic loading and residual stresses will be significantly different from the case where only the cyclic loading is considered. In the damage evolution of surface scratch, the short crack growth is of great importance owing to its apparently anomalous behaviors compared with the long-crack growth. In this paper, the effect of the surface roughness and the residual stress on the short crack growth is studied. Firstly, the surface roughness and the residual stress of 7075-T6 aluminum alloy induced by the high speed milling process with various cutting speeds and feed rates are investigated with the experimental method. The maximum height roughness parameter is measured, which is regarded as the surface defect induced by the milling process. The residual stress on the specimen surface is measured with the X-ray diffraction. Results show that the surface roughness becomes higher with the increase of the feed rate. However, the influence of the cutting speed on the surface roughness is not significant. The residual stresses on the specimen surface are all in the compressive state. The residual stress is more compressive as the feed rate increases. The effects of the process parameters on the surface roughness and the residual stress are described by the fitted formulas. Then a modified model is built to characterize short fatigue crack growth behaviors with the consideration of the residual stress. This model is proved to provide a realistic treatment of the short crack growth, as reflected by comparison with experimental fatigue crack growth data of medium carbon steel and 7075-T6 aluminum alloy published in literature. The effect of surface roughness and residual stress caused by the milling process on the short crack growth is also investigated by using the proposed model. The growth of the scratch is nonlinear when it is subjected to the cyclic load. The compressive residual stress reduces the growth rate of the crack. The crack with larger initial surface roughness grows faster than that with smaller roughness. The correlation of surface roughness, residual stress and crack growth length is obtained by the polynomial fitting. The investigations in this paper can help the damage tolerance design of structures and improve the awareness of the effect of the residual stress and surface roughness induced by the machining process on the short crack growth.

Study on surface roughness and residual stress change during cold forging.

2017 ◽  
Vol 2017.55 (0) ◽  
pp. K0303
Author(s):  
Nuwan KARUNATHILAKA ◽  
Naoya TADA ◽  
Takeshi UEMORI ◽  
Toshiya NAKATA ◽  
Masahiro KAWANO
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Stress Change ◽  
Cold Forging

Experimental Investigation on High-Speed Milling of Aluminum Alloys

2011 ◽  
Vol 418-420 ◽  
pp. 1141-1147
Author(s):  
Yong Liu ◽  
Li Tang Zhang ◽  
Zhi Hong Xu
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Experimental Investigation ◽  
Aluminum Alloys ◽  
High Speed ◽  
Depth Of Cut ◽  
Processing Temperature ◽  
Single Factor ◽  
High Speed Milling ◽  
Radial Depth

High-speed milling is recognized as one of rapidly development machining methods. The article gives details of machining experiments with different aluminum alloys. Through a lot of single factor experiments and the orthogonal multi-factor experiments, and also use method of semi-artificial thermocouple. This paper mainly studies influence of surface roughness and residual stress with changed rotate speed, tooth load and radial depth of cut, and changed law of processing temperature for rotate speed. Though experiments shows that enhancing rotate speed may reduce surface roughness and residual stress within certain limits and the result of experiments is not agree with Carl Salomon’s theory.

Parametric Study of Machining Effect on Residual Stress and Surface Roughness of Nickel Base Super Alloy UDIMET 720

2008 ◽  
Vol 47-50 ◽  
pp. 13-16 ◽  
Author(s):  
S.V. Joshi ◽  
S. Paul Vizhian ◽  
B.R. Sridhar ◽  
K. Jayaram
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Turbine Engine ◽  
Milling Parameters ◽  
Stress Surface ◽  
Nickel Base ◽  
Engine Components ◽  
Super Alloy

Machining parameters such as speed (v), feed (f) and depth of cut (d) play an important role in determining the residual stress as well as the surface roughness of a material. The material used for the present study is a nickel based super alloy Udiment 720 which finds applications in the manufacture of gas turbine engine components. Residual stress and surface roughness measured on this material showed different magnitudes for different combinations of milling parameters but did not reveal any definite trend. Analytical relationships developed between the magnitudes of residual stress, surface roughness and milling parameters indicated that combined effects of the milling parameters influence both residual stress and surface roughness.

scholarly journals Design and Fabrication of Laser Protective Lenses Based on Multilayered Notch Filter with Low Residual Stress and Low Surface Roughness

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1513
Author(s):  
Chuen-Lin Tien ◽  
Hong-Yi Lin ◽  
Kuan-Sheng Cheng ◽  
Chih-Kai Chang
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Filter Design ◽  
Notch Filter ◽  
Transmission Band ◽  
Optical Transmittance ◽  
Electron Beam Evaporation ◽  
Center Wavelength ◽  
Stress Surface ◽  
Probe Microscope

We present a new laser protective lens based on a multilayered notch filter design with low residual stress and low surface roughness. An18-layer notch filter was prepared by electron beam evaporation with an ion-assisted deposition technique, which was composed of SiO2 and Nb2O5 with a center wavelength of 532 nm. The optical transmittance, residual stress, surface roughness, and surface morphology were measured by a UV/VIS/NIR spectrophotometer, Twyman–Green interferometer, scanning probe microscope, Linnik microscopic interferometer, and field-emission scanning electron microscopy (FE-SEM). The transmittance of the notch filters at center wavelength is 0.2%, and the average transmittance of the transmission band is about 70%. The residual stress of the notch filter is −0.298 GPa, and the root mean square surface roughness is 1.88 nm. The experimental results show that the optical transmittance meets the design requirements.

Surface Integrity and Fatigue Property of a High Speed Milled Titanium Alloy

2008 ◽  
Vol 53-54 ◽  
pp. 305-310 ◽  
Author(s):  
Guo Sheng Geng ◽  
Jiu Hua Xu
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Titanium Alloy ◽  
Surface Integrity ◽  
Work Hardening ◽  
High Speed ◽  
Cutting Speed ◽  
Fatigue Property ◽  
Machined Surface ◽  
Metallurgical Structure

Surface integrity has a great effect on the fatigue property of titanium alloy. The surface integrity and fatigue property of a high speed milled Ti-6.5Al-2Zr-1Mo-1V (TA15) titanium alloy were investigated in this research. The main objective of this paper is to study the influence of milling speed on the surface integraty and fatigue property of the machined part. The surface roughness, work hardening, metallurgical structure and residual stress of the machined surface were studied in a cutting speed range of from 50m/min to 300m/min. To verify the relationship between cutting speed and the surface integrity of machined surface, the fatigue property of titanium alloy specimens milled at four different cutting speeds ranging from 50 to 200m/min were compared at two stress levels. This research shows that the cutting speed has little effect on the work hardening, metallurgical structure and residual stress, but the surface roughness decreases with the increasing cutting speed. Therefore, increasing milling speed has a positive effect on the surface integrity and fatigue property of the machined surface.

Tool Wear and Surface Roughness in Milling of Die Steel Using Binderless CBN End Mill

2017 ◽  
Vol 11 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Kazuya Hamaguchi ◽  
◽  
Hiroyuki Kodama ◽  
Koichi Okuda ◽  
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
High Speed ◽  
Wear Volume ◽  
End Mill ◽  
Die Steel ◽  
Heat Treated ◽  
Finished Surface ◽  
End Mills ◽  
Heat Treated Steel

In this study, the authors describe the cutting characteristics of binderless CBN end mills in milling of die steel. A single flute radius end mill having a diameter of 0.5 mm and corner radius of 0.02 mm was in the experiment. Heat-treated steel, stainless steel, and high-speed tool steel were cut using a high-speed spindle, allowing for the analyses of tool wear and surface roughness. The results revealed that the wear volume increased with an increase in the hardness of the work material although the edge retreat amount after cutting 25 m was less than 5 μm. The average surface roughness of the finished surface was less than 15 nm in all the work materials. A mirror-finished surface was also obtained. This result contributes to the automation of the polishing process of metal molds and to the more efficient use of labor.

Materials Factors Influencing the Initiation of Near-Neutral pH SCC on Underground Pipelines

2000 ◽  
Author(s):  
John A. Beavers ◽  
Joshua T. Johnson ◽  
Robert L. Sutherby
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Chemical Composition ◽  
Cyclic Stress ◽  
Strain Behavior ◽  
Inclusion Properties ◽  
Neutral Ph ◽  
Underground Pipelines ◽  
Factors Influencing ◽  
Stress Surface

This paper summarizes the results of research, funded by the Canadian Energy Pipeline Association (CEPA), to determine whether the initiation of near-neutral pH stress corrosion cracking (SCC) could be correlated with pipe metallurgical factors. The factors considered included residual stress, surface roughness, chemical composition, cyclic stress-strain behavior, inclusion properties (number, area, and composition), microhardness, and local galvanic behavior. The project focused on pipes installed from the 1950s through 1970s that exhibit near-neutral-pH SCC. Fourteen pipe samples were examined, ranging in diameter from 8 to 42 inches and grades from X52 to X70.

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