A new multi-scratching approach to identify the interaction between grit size and surface roughness on the residual stresses during belt-finishing

AbstractThe manufacturing of case-hardened gears usually consists of several complex and expensive steps to ensure high load carrying capacity. The load carrying capacity for the main fatigue failure modes pitting and tooth root breakage can be increased significantly by increasing the near surface compressive residual stresses. In earlier publications, different shear cutting techniques, the near-net-shape-blanking processes (NNSBP’s), were investigated regarding a favorable residual stress state. The influence of the process parameters on the amount of clean cut, surface roughness, hardness and residual stresses was investigated. Furthermore, fatigue bending tests were carried out using C-shaped specimens. This paper reports about involute gears that are manufactured by fineblanking. This NNSBP was identified as suitable based on the previous research, because it led to a high amount of clean cut and favorable residual stresses. For the fineblanked gears of S355MC (1.0976), the die edge radii were varied and the effects on the cut surface geometry, hardness distribution, surface roughness and residual stresses are investigated. The accuracy of blanking the gear geometry is measured, and the tooth root bending strength is determined in a pulsating test rig according to standardized testing methods. It is shown that it is possible to manufacture gears by fineblanking with a high precision comparable to gear hobbing. Additionally, the cut surface properties lead to an increased tooth root bending strength.

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Effects of Roughness on Stresses in an Oxide Scale Formed on a Superalloy Substrate

Coatings ◽

10.3390/coatings11040479 ◽

2021 ◽

Vol 11 (4) ◽

pp. 479

Author(s):

Yang Zhao ◽

Fan Sun ◽

Peng Jiang ◽

Yongle Sun

Keyword(s):

Residual Stress ◽

Surface Roughness ◽

Residual Stresses ◽

Oxide Scale ◽

Rough Surface ◽

Alumina Scale ◽

Growth Stress ◽

Oxide Growth ◽

Substrate Thickness ◽

Roughness Effect

The effects of surface roughness on the stresses in an alumina scale formed on a Fecralloy substrate are investigated. Spherical indenters were used to create indents with different radii and depths to represent surface roughness and then the roughness effect was studied comprehensively. It was found that the residual stresses in the alumina scale formed around the rough surface are almost constant and they are dominated by the curvature rather than the depth of the roughness. Oxidation changes the surface roughness. The edge of the indent was sharpened after oxidation and the residual stress there was released presumably due to cracking. The residual stresses in the alumina scale decrease with increase in oxidation time, while the substrate thickness has little effect, given that the substrate is thicker than the alumina scale. Furthermore, the effect of roughness on the oxide growth stress is analysed. This work indicates that the surface roughness should be considered for evaluation of stresses in coatings.

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Influence of High-Productivity Process Parameters on the Surface Quality and Residual Stress State of AISI 316L Components Produced by Directed Energy Deposition

Journal of Materials Engineering and Performance ◽

10.1007/s11665-021-05954-3 ◽

2021 ◽

Author(s):

Gabriele Piscopo ◽

Alessandro Salmi ◽

Eleonora Atzeni

Keyword(s):

Surface Roughness ◽

Residual Stresses ◽

Surface Quality ◽

Process Parameters ◽

Energy Deposition ◽

Industrial Applications ◽

High Productivity ◽

Directed Energy Deposition ◽

Productivity Process ◽

Directed Energy

AbstractThe production of large components is one of the most powerful applications of laser powder-directed energy deposition (LP-DED) processes. High productivity could be achieved, when focusing on industrial applications, by selecting the proper process parameters. However, it is of crucial importance to understand the strategies that are necessary to increase productivity while maintaining the overall part quality and minimizing the need for post-processing. In this paper, an analysis of the dimensional deviations, surface roughness and subsurface residual stresses of samples produced by LP-DED is described as a function of the applied energy input. The aim of this work is to analyze the effects of high-productivity process parameters on the surface quality and the mechanical characteristics of the samples. The obtained results show that the analyzed process parameters affect the dimensional deviations and the residual stresses, but have a very little influence on surface roughness, which is instead dominated by the presence of unmelted particles.

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EFFECTS OF BELT SPEED, PRESSURE AND GRIT SIZE ON THE SANDING OF Pinus elliottii WOOD

CERNE ◽

10.1590/01047760201521011216 ◽

2015 ◽

Vol 21 (1) ◽

pp. 45-50 ◽

Cited By ~ 3

Author(s):

Manoel Cléber de Sampaio Alves ◽

Luiz Fernando Frezzatti Santiago ◽

Marcos Tadeu Tiburcio Gonçalves ◽

Ivaldo De Domênico Valarelli ◽

Francisco Mateus Faria de Almeida Varasquim

Keyword(s):

Surface Roughness ◽

Analysis Of Variance ◽

Block Design ◽

Pinus Elliottii ◽

Grit Size ◽

Significance Level ◽

Belt Speed ◽

Randomized Complete Block Design ◽

Four Levels ◽

Temperature Levels

The present paper aims to evaluate the influence of the factors (belt speed, pressure and grit size) on the output parameters (temperature and surface roughness) for Pinus elliottii wood sanding, processed parallel to the fibers. Three levels of belt speed, three levels of pressure and four levels of grit size were employed, with six replicates for each process, totaling 216 observations. The experiment conducted under a randomized complete block design (RCBD). The results were analyzed employing the analysis of variance (ANOVA) with 5% of significance level. Only grit sizes were significant to different temperature levels. The same outcome was observed for roughness, where only grits sizes were significant. No interaction between the pressure and belt speed factors were observed for all the results analyzed.

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The Effect of Several Finishing Processes on the Fatigue Resistance of Hole Surfaces

Journal of Engineering Materials and Technology ◽

10.1115/1.3226435 ◽

1989 ◽

Vol 111 (1) ◽

pp. 71-73 ◽

Cited By ~ 3

Author(s):

M. O. Lai ◽

A. Y. C. Nee

Keyword(s):

Surface Roughness ◽

Plastic Deformation ◽

Fatigue Life ◽

Residual Stresses ◽

Fatigue Resistance ◽

Radial Direction ◽

Fatigue Loading ◽

Steel Plates ◽

Finishing Processes ◽

Compressive Residual Stresses

This investigation examines the effects of different finishing processes on the fatigue life of premachined holes in Assab 760 steel plates. The finishing processes studied were reaming, ballizing, and emery polishing. A general decrease in fatigue life with increase in surface roughness is observed for all the processes employed. In comparing the different processes, for a constant surface roughness, polishing is generally found to give the longest fatigue life while ballizing, in spite of the greater compressive residual stresses induced on the surface of the finished hole, the shortest. The surprising phenomenon was found to be attributed to the amount of plastic deformation occurred before fatigue loading. For Assab 760 steel, a prestrain in the radial direction of less than about 2.5 percent appeared to reduce the fatigue resistance of the material.

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Short Crack Propagation Model Applied to Shot Peened Aluminium Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.65.53 ◽

2009 ◽

Vol 65 ◽

pp. 53-61 ◽

Cited By ~ 2

Author(s):

J. Solis ◽

J. Oseguera-Peña ◽

I. Betancourt

Keyword(s):

Surface Roughness ◽

Residual Stresses ◽

Crack Propagation ◽

Aluminium Alloys ◽

Micromechanical Model ◽

High Strength ◽

Crack Arrest ◽

Propagation Model ◽

Safe Load ◽

Compressive Residual Stresses

The Navarro-Rios micromechanical model was used to assess the bounds of two different damage zones: crack arrest region and crack propagation region of controlled shot peening (CSP) of high strength aluminium alloys. Performance of CSP in terms of fatigue resistance was investigated. This comparison indicated that CSP in terms of fatigue depends on the competition between its beneficial and detrimental products, i.e. surface roughness and compressive residual stresses respectively. The gathered information can be used for safe load determinations in design.

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Rated definition of degree of cutter coating influence upon parameters of surface layer quality of parts worked

Science intensive technologies in mechanical engineering ◽

10.12737/article_595256f1a5fff7.38096621 ◽

2017 ◽

Vol 2 (7) ◽

pp. 20-24

Author(s):

Вячеслав Безъязычный ◽

Vyacheslav Bezyazychnyy ◽

Максим Басков ◽

Maksim Baskov

Keyword(s):

Surface Roughness ◽

Surface Layer ◽

Residual Stresses ◽

Layer Surface ◽

Wear Resistant Coatings ◽

Cutter Wear ◽

Definition Of ◽

Surface Layer Quality ◽

The Impact

The impact of cutter wear-resistant coatings upon cutting process parameters and characteristics of surface layer quality in the parts worked: residual stresses, a degree and a depth of work hardening of a surface layer, surface roughness is investigated.

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