Laser clad surfaces for shark-skin effect by high-temperature activation

Schaaf, Peter; Schikora, H.; Höche, Daniel; Lange, Christian; Drescher, Viktor; Wilden, J.

doi:10.1016/j.surfcoat.2008.08.066

Cited by 3 publications

(2 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nowadays, the laser structuring is the most promising method for the fabrication of small riblets with the above‐mentioned features. Using laser light, relatively fast and precise geometrical structuring, including material removal and subsequent oxidation, becomes possible.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Riblet Structures on a Ni‐based Superalloy (PWA1483) for Potential Drag Reduction in High Temperature Applications Based on Laser Optimization

2015

View full text Add to dashboard Cite

We propose a new laser-based fabrication process of small-sized riblets on PWA1483 coated on a 3 mmthin sputtered Ni/Cr/Ni multilayer. Laser ablation was used for local material removal. Subsequent oxidation was used to provide an optimal riblet dimensions for a drug reduction and oxidation resistance. As a result of the heat treatment, a 7 mm oxide film was formed. The oxide film consists of two different oxide layers: while the upper one is formed of a dense Cr 2 O 3 layer with NiO, Cr 2 NiO 4 , and TiO 2 inclusions, the bottom one mainly consists of alpha-Al 2 O 3 . Between the riblets, a TiO 2 layer was formed on the top of Cr 2 O 3 layer. First mechanical tests showed a promising riblet stability under the low-cycle fatigue load, under tension, and under quasi-cyclic bending load. The riblets also exhibit no severe failure by applying a quasi-cyclic bending stress of 900 MPa for 200 times. Furthermore, cyclic tensile loading with a mean load of 500 MPa and an amplitude of 220 MPa corresponding to a strain range of 0.35% (stress level of R ¼ 0.35) led to no damage of the riblet structure.

show abstract

Section: Introductionmentioning

confidence: 99%

Fabrication of Riblet Structures on a Ni‐based Superalloy (PWA1483) for Potential Drag Reduction in High Temperature Applications Based on Laser Optimization

2015

View full text Add to dashboard Cite

show abstract

“…Such coatings aim to combine the properties of self-cleaning and drag-reduction by embedding ceramic particles with a negative thermal expansion coefficient (NTEC) into a hotgas corrosion-resistant metallic matrix, e. g. a superalloy. Due to these characteristics, these composite coatings could be beneficially used in turbines [1,2]. The synthesis of the NTEC ceramic Y 2 W 3 O 12 has already been investigated by different authors [3 -6].…”

Section: Introductionmentioning

confidence: 99%

In-situ synthesis of Y2W3O12 within a Co-based superalloy powder mixture

Hopfeld

Wilden

Drescher

et al. 2010

International Journal of Materials Research

View full text Add to dashboard Cite

In-situ synthesis of Y 2 W 3 O 12 within a Co-based superalloy powder mixture In this work, the synthesis of the negative thermal expansion ceramic Y 2 W 3 O 12 within a Co-based superalloy was analyzed in detail. On the basis of thermal analysis of the synthesis from the feedstock powders Y 2 O 3 and WO 3 further experiments were conducted. Thermal behavior and stability of different mixtures of the powders Y 2 O 3 , WO 3 and the Co-based superalloy were investigated. The qualitative and quantitative results of the synthesis separately and within the superalloy are presented as achieved by energy dispersive X-ray analysis, X-ray powder diffraction, differential thermal analysis and thermal gravimetric analysis. It was found that the synthesis of yttrium tungstate inside the Co-based superalloy is possible with a defined temperature program and a simple basic production process of powder mixtures.

show abstract