Abstract
Vibratory finishing is a process developed for surface treatment. The original aim of this process was the improvement of surface roughness and the deburr of workpieces. In recent years, the vibratory finishing was also used to increase the fatigue strength. Aim of this work is the observation of the influence of vibratory finishing on surface layer properties and its resulting influence on the fatigue strength of steel (27MnCrB5-2) and aluminium (AW-2007) specimens as well as to develop an approach for assessing the fatigue strength of vibratory finished samples on the basis of standardized approaches. Therefore, the focus lies on the systematic analysis of the vibratory finishing process and on the influence of different process parameters on the local surface topography and surface layer properties of the investigated samples. For this purpose, roughness-time curves are experimentally created and the resulting surface structure, residual stresses and hardness condition are iteratively evaluated. After evaluating the ideal process parameters for the surveyed vibratory finishing process, steel and aluminium specimens are prepared according to these observations and further cyclically tested. For this purpose Wöhler tests with specimens before and after vibratory finishing are carried out. For both materials an increase of the high-cycle fatigue strength is observed, which equals an enhancement by 24% for steel and 20% for aluminium. To assess the fatigue strength, the standardized calculation scheme of the FKM-guideline is applied, in which the experimental determined surface layer properties are considered. The results show an underestimated fatigue strength of 1% for the steel and 11.5% for the aluminium specimens, which allows a reliable and conservative assessment according to the presented approach. As basis for further analyses, for deepening of the knowledge of vibratory finishing process and its influence on surface topography and surface layer properties, recommendations for further possible parameters surveys and scientific investigations are suggested at the end of the work.
Translated title of the contribution | Effect of vibratory finishing on the fatigue strength of aluminium and steel specimens |
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Original language | German |
Qualification | Dipl.-Ing. |
Awarding Institution |
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Supervisors/Advisors |
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Award date | 23 Oct 2020 |
Publication status | Published - 2020 |
Bibliographical note
embargoed until nullKeywords
- vibratory finishing
- fatigue strength
- surface roughness
- residual stresses
- hardness