Wyniki wyszukiwania - BazTech

1

Influence of Single-Stage and Duplex Shot Peening on Surface Roughness and Residual Stresses in Al Mg5 Mn1 Sc0,8 Zr0,4 Alloy

Byczkowska P., Sawicki J., Januszewicz B., Stegliński M.

Archives of Metallurgy and Materials

|

2018

|

Vol. 63, iss. 1

505--511

EN

Conventional shot peening (SP) is cheap surface treatment widely used to enhance fatigue life of mechanical components [3,4]. Basically, it is shooting small particles (shots) on the surface of the sample. However, the process itself is so complex that a lot of companies are not able to optimally employ it due to the amount of parameters that must be controlled all at the same time. The duplex process consists in two stages of shot-peening treatment. The first one consist of shot-peening with spherical cast steel shots or cut wire shots. During the second stage the samples processed in stage one were subject to shot-peening with glass beads. In this work, RSA-501 aluminium alloy was shot peened using shots of different material and diameter and tested using a measurement of residual stresses and surface roughness. Tests and studies conducted so far on RSA-501 aluminium alloy demonstrate that bombardment by a treatment medium in the form of glass beads or shots of various shapes and diameters induces permanent plastic deformation of the surface layer. The roughness achieved after the shot-peening process was determined for each treatment medium. The largest value of Ra parameter was achieved for cut wire shots and this result is consistent with the above-mentioned theoretical knowledge. This medium is the most aggressive one to the surface being treated primarily due to the sharp edges of shots. The duplex process was successful in obtaining higher values of compressive stresses in surface layer than values achievable in conventional single-stage shot peening process.

2

Analysis of the impact of double shot peening on the value of roughness parameter and distribution of stresses in the RSA 501 alloy

Byczkowska Paulina, Sawicki Jacek, Januszewicz Bartłomiej, Stegliński Mariusz

Advances in Science and Technology. Research Journal

|

2018

|

Vol. 12, no 3

1--9

EN

The bead blasting process is widespread in both the automotive and aerospace industry and is performed in order to improve the fatigue strength of various components. Bead blasting is a cold plastic forming process during which the surface of the material processed is hit by small, hard particles consisting of steel pellets, bearing balls or glass beads. It increases the hardness of the outer layer and establishes compression stresses inside it, which is why this processing is often used to improve fatigue strength. Contrary to other peening methods, bead blasting does not result in a reduction in the height of the processed surface’s unevenness in most cases. Shot peening changes the residual tensile stresses into residual compression stresses, thanks to which, the lifetime of the parts processed is extended and their carrying capacity is increased. The double shot peening process proposed by the authors consists in a two-stage bead blasting process. The first stage consists in blasting with round cast steel pellets, pellets cut from wire or cast iron pellets. During the second stage the same samples underwent glass bead blasting. The tests conducted on the RSA-501 aluminum alloy indicate that as a result of the processing medium’s impact in the form of glass beads or pellets of different diameter and shape, a permanent plastic deformation of the material surface occurs. On the basis of the obtained results it is possible to infer that the choice of parameters of both conventional shot peening and the double shot peening determine the impact thereof on the material’s mechanical properties. Thanks to the application of the double shot peening process there is a noticeable decrease in value of the Ra parameter, by about 40% on average. When analyzing the compressive stress results it is possible to state that after the first blasting process the value of stress was increasing when moving deeply into the sample from its surface, while after the glass bead blasting the value of compressive stress was significantly higher already near the surface. Double shot peening results in an increase in the value of compressive stresses by 40-50% when compared to conventional blasting.

3

Analysis of the impact of double shot peening on the value of roughness parameter and distribution of stresses in the RSA 501 alloy

Byczkowska P., Sawicki J., Januszewicz B., Stegliński M.

Advances in Science and Technology. Research Journal

|

2017

|

Vol. 11, no 3

1--9

EN

The bead blasting process is widespread in both the automotive and aerospace industry and is performed in order to improve the fatigue strength of various components. Bead blasting is a cold plastic forming process during which the surface of the material processed is hit by small, hard particles consisting of steel pellets, bearing balls or glass beads. It increases the hardness of the outer layer and establishes compression stresses inside it, which is why this processing is often used to improve fatigue strength. Contrary to other peening methods, bead blasting does not result in a reduction in the height of the processed surface’s unevenness in most cases. Shot peening changes the residual tensile stresses into residual compression stresses, thanks to which, the lifetime of the parts processed is extended and their carrying capacity is increased. The double shot peening process proposed by the authors consists in a two-stage bead blasting process. The first stage consists in blasting with round cast steel pellets, pellets cut from wire or cast iron pellets. During the second stage the same samples underwent glass bead blasting. The tests conducted on the RSA-501 aluminum alloy indicate that as a result of the processing medium’s impact in the form of glass beads or pellets of different diameter and shape, a permanent plastic deformation of the material surface occurs. On the basis of the obtained results it is possible to infer that the choice of parameters of both conventional shot peening and the double shot peening determine the impact thereof on the material’s mechanical properties. Thanks to the application of the double shot peening process there is a noticeable decrease in value of the Ra parameter, by about 40% on average. When analyzing the compressive stress results it is possible to state that after the first blasting process the value of stress was increasing when moving deeply into the sample from its surface, while after the glass bead blasting the value of compressive stress was significantly higher already near the surface. Double shot peening results in an increase in the value of compressive stresses by 40-50% when compared to conventional blasting.