scholarly journals Influence of Semi-Random and Regular Shot Peening on Selected Surface Layer Properties of Aluminum Alloy

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7620
Author(s):  
Jakub Matuszak ◽  
Kazimierz Zaleski ◽  
Agnieszka Skoczylas ◽  
Krzysztof Ciecieląg ◽  
Krzysztof Kęcik
Keyword(s):  
Surface Roughness ◽  
Surface Layer ◽  
Aluminum Alloy ◽  
Shot Peening ◽  
Workpiece Surface ◽  
Microhardness Distribution ◽  
Ball Diameter ◽  
Surface Layer Hardening ◽  
Reduced Surface

This paper attempts to compare regular shot peening (RSP) and semi-random shot peening (SRSP). A characteristic of the first method is that the peening elements hit the treated surface in sequence, with a regular distance maintained between the dimples. The other method (SRSP) is a controlled modification of the shot-peening process, which is random by nature. The shot-peening method used in this study differs from conventional shot peening (shot blasting and vibratory shot peening) in that it allows controlled and repeatable determination of the configuration and distribution of impacts exerted by the peening element on the workpiece surface, which makes the process more repeatable and easier to model. Specimens of EN-AW 7075 aluminum alloy were used for testing. The following variables were used in the experiments: ball diameter, impact energy, and distance between the dimples. Microhardness distribution in the surface layer, 2D surface roughness, and surface topography were analyzed. FEM simulations of the residual stress distribution in the surface layer were performed. It has been found that regular shot peening results in reduced surface roughness, while semi-random shot peening leads to higher surface layer hardening.

Calculated determination of strength characteristics of assembly joints with tightness taking into account the technological conditions for processing the surfaces

2021 ◽  
pp. 30-34
Author(s):  
V.F. Bezjazychnyi ◽  
M.A. Prokofiev ◽  
F.R. Zhirnova
Keyword(s):  
Surface Roughness ◽  
Surface Layer ◽  
Quality Indicators ◽  
Strength Characteristics

The method of calculating the strength of the joint with tension taking into account the technological conditions for processing the mating surfaces, which determine the quality indicators of the surface layer of the material of these surfaces: the surface roughness and the degree of their hardening, was described.

scholarly journals The Effect Of Two-Stage Age Hardening Treatment Combined With Shot Peening On Stress Distribution In The Surface Layer Of 7075 Aluminum Alloy

2015 ◽  
Vol 60 (3) ◽  
pp. 1993-1998 ◽  
Author(s):  
Ł. Kaczmarek ◽  
P. Zawadzki ◽  
M. Stegliński ◽  
R. Wójcik ◽  
M. Klich ◽  
...  
Keyword(s):  
Surface Layer ◽  
Aluminum Alloy ◽  
Stress Distribution ◽  
Shot Peening ◽  
Age Hardening ◽  
7075 Aluminum Alloy ◽  
Two Stage ◽  
Compressive Stresses ◽  
Hardening Treatment ◽  
Thermo Mechanical Treatment

Abstract The article present the results of the study on the improvement of mechanical properties of the surface layer of 7075 aluminum alloy via two-stage aging combined with shot peening. The experiments proved that thermo-mechanical treatment may significantly improve hardness and stress distribution in the surface layer. Compressive stresses of 226 MPa±5.5 MPa and hardness of 210±2 HV were obtained for selected samples.

Influence of Laser Shot Peening Parameters on the Surface Hardness and Roughness of 7075 Aluminum Alloy

2018 ◽  
Vol 920 ◽  
pp. 83-88
Author(s):  
Jun Hao Zhang ◽  
Xiu Quan Cheng ◽  
Qin Xiang Xia ◽  
Jia Yu Li
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Shot Peening ◽  
Surface Hardness ◽  
Laser Shot ◽  
7075 Aluminum Alloy ◽  
Alloy Specimen ◽  
Structural Parts ◽  
The Impact ◽  
Overlap Rate

The laser shot peening has the widely application prospect in aircraft structural parts repairment. The influence of laser shot peening parameters on the surface hardness and surface roughness has guiding significance for laser shot peening process. The variation law of surface hardness and surface roughness in the peening area of 7075 aluminum alloy were obtained based on the experiment research. The results show that the surface hardness improves effectively after laser shot peening, and the maximum hardness is 205.4HV, which is improved by 19.49% compared with the original hardness. Besides, the surface roughness of the rough specimen decreases; whereas, those of the smooth specimen increases after laser shot peening. However, both the surface hardness and surface roughness tend to be saturated when the impact times exceeds 3 times or the overlap rate exceeds 50%. Therefore, a good repairment effect can be obtained with 3 impact times and 50% overlap rate for the 7075 aluminum alloy specimen.

Application of the Concept of Local Fatigue Strength after Shot Peening of Notched Components Based on Numerical Simulations

2010 ◽  
Vol 638-642 ◽  
pp. 912-917
Author(s):  
Manuel Klemenz ◽  
Volker Schulze
Keyword(s):  
Surface Layer ◽  
Fatigue Strength ◽  
Fatigue Limit ◽  
Shot Peening ◽  
Surface Characteristics ◽  
Complex Stress ◽  
Simulated Surface ◽  
Induced Changes ◽  
Notched Components

Shot Peening is a well established mechanical surface treatment to induce compressive residual stresses and work hardening into the surface layer of components exposed to cyclic loading. Due to the induced changes in the surface layer, the fatigue limit increases significantly. The concept of local fatigue strength is based on the comparison of the locally effective fatigue limit with locally active loads in order to estimate the maximum outer loading that will not exceed fatigue limit. In this paper an approach of using simulated surface characteristics after shot peening for the determination of the local fatigue strength will be presented. The complex stress distribution due to cyclic bending of notched geometries will also be determined by FEM. Finally the simulated estimation of the fatigue limit of differently notched specimens of AISI 4140 will be verified with experimentally determined fatigue limits.

scholarly journals Determination of the Optimal Coverage for Heavy-Duty-Axle Gears in Shot Peening

2021 ◽  
Author(s):  
Hongzhi Yan ◽  
Pengfei Zhu ◽  
Zhi Chen ◽  
Hui Zhang ◽  
Yin Zhang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Dislocation Density ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Heavy Duty ◽  
High Coverage ◽  
Service Lifetime ◽  
Maximum Value

Abstract Pitting and wear often appear on heavy-duty-axle gears due to their harsh working conditions, such as high torques, high loads and poor lubrication. Shot peening is a popular surface strengthening method for gears. In order to ensure complete coverage during shot peening, 100%~200% coverage is usually prescribed for most gears. However, it is difficult to effectively improve the contact fatigue and wear resistance of heavy-duty-axle gears. Generally, increasing shot peening coverage can heighten the compressive residual stress for prolonging the service lifetime of gears. Whereas, high coverage levels may cause the deterioration of surface roughness, thus increase the noise and vibration of gears. To address this issue, this paper deals with the determination of optimal coverage for heavy-duty-axle gears by experimental tests. The influence of shot peening coverage on the surface integrity of gears is analyzed in terms of residual stress, microhardness, surface morphology and dislocation density. The results show that the maximum compressive residual stress increases first and then keeps stable with the increase of coverage, and the maximum value is −1172.10 MPa. The microhardness peak increases obviously in the beginning and then slowly rises with the increase of coverage, and the maximum value is 747.5 HV1.0. The surface roughness (Ra) decreases initially and then enhances with the increase of coverage, and the minimum value is 0.99 μm under the coverage of 1000%. The dislocation density increases with the increase of coverage, and the maximum value is 3.70×1016 m-2. Numerous damages (microscalings, spallings) occur on the treated gear tooth flank affecting the residual stress distribution and roughness under high coverage levels. Taking into consideration of service lifetime, working noise and economic efficiency, the coverage of 1000% is the optimal coverage for heavy-duty-axle gears in shot peening.

scholarly journals Effect of Slide Burnishing on the Surface Layer and Fatigue Life of Titanium Alloy Parts

2019 ◽  
Vol 19 (4) ◽  
pp. 35-45
Author(s):  
K. Zaleski ◽  
A. Skoczylas
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Surface Layer ◽  
Fatigue Life ◽  
Average Roughness ◽  
Maximum Increase ◽  
Burnishing Process ◽  
Slide Burnishing ◽  
Machining Fluids ◽  
Reduced Surface

AbstractThe paper presents the results of a study investigating the effect of slide burnishing on the surface roughness, surface layer microhardness and fatigue life of Ti6Al2Mo2Cr titanium alloy parts. The burnishing process was performed with the use of a diamond tip tool. Different machining fluids were used as machining media. Prior to burnishing, the samples were subjected to turning. The burnishing process led to reduced surface roughness (average roughness Ra decreased by 3.5 times and roughness Rz decreased by 2.5 times) as well as increased surface layer microhardness (microhardness maximum increase by 12%) and fatigue life of the tested parts. A relationship between the machining medium and the burnishing effects was also observed. The addition of a surface-active polymethyl methacrylate solution to the machining medium led to an increase in the surface layer microhardness and fatigue life of the workpiece.

scholarly journals The influence of vibratory shot peening on the selected properties of the surface layer elements made of cast iron

Mechanik ◽  
2019 ◽  
Vol 92 (11) ◽  
pp. 739-741
Author(s):  
Kazimierz Zaleski ◽  
Agnieszka Skoczylas
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Surface Layer ◽  
Cast Iron ◽  
Shot Peening ◽  
Experimental Investigations ◽  
Spheroidal Graphite ◽  
Absolute Value ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron

The results of experimental investigations influence of vibratory shot peening on surface roughness and residual stress of spheroidal graphite cast iron objects were presented. The surfaces before vibratory shot peening were milled using different feed. After vibratory shot peening surface roughness Ra = 0.7÷0.9 μm was obtained and in surface layer compressive residual stress, with the maximum (absolute) value from 170 MPa to 330 MPa at a depth 0.4÷0.7 mm have been formed. For accepted vibratory shot peening condition it was recommended to use time of about 8 minutes.

Water Jet Shot Peening Strengthening Surface Roughness

2013 ◽  
Vol 670 ◽  
pp. 174-179 ◽  
Author(s):  
X. Dong ◽  
R.Z. Guo ◽  
S.W. Song ◽  
C.Y. Zhuo
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Shot Peening ◽  
Water Jet ◽  
Target Distance ◽  
Material Surface ◽  
Material Strength ◽  
Scanning Velocity ◽  
Alloy Material ◽  
Pressure Nozzle

Shot peening pressure, nozzle scanning velocity, and target distance were chosen as effect factors when shot peening test to 45 steel and 2Al1 aluminum alloy material was made by water jet. Adopted stylus method for measuring shot peening surface roughness Ra and Ry, observed macroscopically shape character of shot peening surface by scanning electron microscope. The results indicated that shot peening pressure, nozzle scanning velocity, target distance caused uniform effect rules on shot peening surface roughness of 45 steel and 2Al1 aluminum alloy material, surface roughness Ra augments as the increase of shot peening pressure and minishs as the increase of scanning velocity, furthermore, there exists the biggest surface roughness target distance. When shot peening target distance was less than the biggest surface roughness target distance, surface roughness Ra and Ry tend to augment as the increase of target distance and inversely proportional to the material strength. When gives less original surface roughness and lower shot peening pressure, it’s not suitable for using Ry to represent shot peening surface roughness but Ra. When shot peened excessively, the surface of the material occurred body exfoliation and corrosion.

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