The effect of diamond burnishing on structure and properties of detonation-gas coatings on gas-turbine engine parts

Duncheva

Fatigue Fract Eng Mat Struct

et al. 2019

The slide burnishing process causes cyclic loading of the surface being treated, which provokes cyclic hardening. Using a forced‐controlled indentation test, the sixth “loading‐unloading” cycle was stabilised. The effect of the number of passes and the cyclic loading coefficient (CLC) on the fatigue performance of slide burnished specimens was investigated. Rotating bending fatigue tests were conducted using nine groups of hourglass shaped specimens, which were slide burnished through a different number of passes and CLC values. A stabilised cycle of the surface layer achieved with six passes, lead to largest fatigue limit, whereas the CLC exerted negligible influence on the fatigue performance. The observed phenomenon was explained through different residual stress relaxation rates, due to the rotating bending load, as well as with the obtained surface layer microstructure. The residual stress relaxation was investigated through rotating bending fatigue tests, using cylindrical fatigue specimens, followed by X‐ray stress analysis.

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Section: Introductionmentioning

confidence: 99%

Effect of cyclic hardening on fatigue performance of slide burnished components made of low‐alloy medium carbon steel

Duncheva

Fatigue Fract Eng Mat Struct

et al. 2019

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“…Apart from deep rolling, it is appropriate to use slide burnishing (SB) for enhancement of fatigue strength of symmetrical rotational components. The essential difference between the two processes is determined by the type of contact between the workpiece and the deforming element, that is, rolling contact and sliding friction contact, respectively.…”

Section: Introductionmentioning

confidence: 99%

Effect of slide burnishing basic parameters on fatigue performance of 2024‐Т3 high‐strength aluminium alloy

Fatigue Fract Eng Mat Struct

Dunchev

et al. 2017

The effect of slide burnishing (SB) on the high‐cycle fatigue (HCF) performance of 2024‐T3 high‐strength aluminium alloy has been studied. After SB with optimum basic process parameters under ‘minimum roughness’ criterion, the 107 cycle fatigue strength increases with 25% – from 180 to 225 MPa, fatigue life is increased more than 50 times, and the roughness obtained reaches up to Ra = 0.05 μm. Further, various combinations of burnishing force and deforming element radius have been applied to reach maximum HCF performance despite roughness obtained. It has been established that with the optimum combination under ‘maximum HCF performance’ criterion, 107 cycle fatigue strength increases with 44% – from 180 to 260 MPa as the roughness obtained is Ra = 0.25 μm. This significant enhancement in the HCF performance is due to introduced beneficial residual compressive stresses. They shift the fatigue crack initiation site from surface to subsurface layers and, as a result, the nucleation and propagation of the first‐mode fatigue cracks are retarded. In order to establish the fatigue limit (based on 2 × 108 cycles), a combined approach, based on limited Wöhler's curve and Locati's method, has been applied. The fatigue limit of 2024‐T3 high‐strength aluminium alloy can be increased up to 250 MPa using SB with optimal basic parameters under ‘maximum HCF performance’ criterion.

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Slide burnishing—review and prospects

Duncheva

Int J Adv Manuf Technol

et al. 2019