Thermally sprayed coatings for the valve industry

Bobzin, Kirsten; Engler, Thomas W.; Joung, Yeon; Oechsner, Matthias; Schulz, M.; Scheerer, Herbert; Heinemann, H.; Wietheger, Wolfgang

doi:10.1002/mawe.202100032

Cited by 4 publications

(2 citation statements)

References 21 publications

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“…With the coating P--, a promising process point was identified which should be used in future to develop new types of coatings for the valve industry. In previous studies (Ref 4,20,21), it was shown that the integration of solid lubricants reduces the wear of conventionally used valve coatings. In subsequent studies, the integration of solid lubricants into HVAF-sprayed fine feedstock material coatings will be investigated.…”

Section: Discussionmentioning

confidence: 99%

Development of Near Net Shaped Coatings for Reduced Postprocessing Costs in Valves

et al. 2023

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Thermally sprayed WC/CoCr coatings are established in the valve industry for wear protection. However, conventional coatings have to be cost-intensive postprocessed. Therefore, the aim of this study is to develop near net shaped (nns) WC/CoCr coatings with a high wear resistance in order to avoid the expensive grinding postprocess. For the development of the nns coatings, a parameter study is used to investigate the influence of the stand-off distance and hydrogen volume flow rate in the HVAF process. The parameter study indicates the influence of the hydrogen volume flow and the stand-off distance on the porosity, microhardness and wear resistance of the coatings. The developed coatings exhibit a low porosity and high wear resistance. Through the correlation of the coating properties with the process parameters, promising parameter ranges for a further development of HVAF-sprayed nns coatings of WC/CoCr can be identified. With these results, first benchmarks for HVAF process parameters, hydrogen flow rate and stand-off distance could be delivered, advancing the overall goal of reducing manufacturing costs of valves.

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Section: Discussionmentioning

confidence: 99%

Development of Near Net Shaped Coatings for Reduced Postprocessing Costs in Valves

et al. 2023

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“…For a reference feedstock, the commercial 86WC/10Co4Cr powder Amperit 507.059 from Ho ¨gana ¨s (Du ¨sseldorf, Germany) is chosen. The carbide sizes in this commercial powder extend into the ultra-fine scale of Ø WC & 200-400 nm with a particle size distribution of d10/d50/ d90 = 11 lm/18 lm/29 lm and an apparent bulk density of q = 5.8 g/cm 3 .…”

Section: Experimental Procedures Feedstock Materialsmentioning

confidence: 99%

Investigation of Novel Nano-carbide WC/CoCr Coatings Applied by HVAF

et al. 2023

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Wear leads to high material and energy losses in various industries. The manufacturing of novel nano-carbide WC/CoCr powder feedstock materials promises a further increase in the performance of thermally sprayed wear protection coatings. A novel experimental powder and a commercial ultra-fine carbide WC/CoCr reference are thermally sprayed onto a 1.0038 substrate by High Velocity Air Fuel (HVAF) spraying. The specimens are metallographically prepared and analyzed by means of light microscopy (LM) and scanning electron microscopy (SEM). Vickers Hardness testing is conducted by micro-indentation, and the porosities are determined by optical image analysis. X-ray diffractometry (XRD) analysis is used to investigate the phase retention. Fine nanocrystalline WC structures are preserved in the dense coatings. A significant effect of powder type on the porosity of the coating was found. No systematic relationships could be identified between the coating structure and the two parameter settings. It was possible to influence decarburization via both the powder type and the selected parameters. The resulting experimental and commercial nanostructured WC/CoCr coatings exhibit high, narrow hardness values with medians of 1.400 < HV0.3 < 1.470. The novel nanostructured coating can contribute to reduced wear and therefore improve the efficient utilization of critical raw materials like tungsten.

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Fretting Behavior of WC-Co-Cr Coatings Against QT Steel in Bolted Joint

Haaja,

Varis,

Laurila

et al. 2024

J Therm Spray Tech

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Fretting damage on contacting surfaces introduces major challenges in mechanical assemblies. Thermal sprayed hardmetal coatings are extensively used for surface modification in tribological applications under demanding conditions and may also be subjected to fretting-inducing loading. In the present work, the fretting behavior of High Velocity Oxy-Fuel (HVOF) and High Velocity Air–Fuel (HVAF) sprayed WC-10Co-4Cr coatings against quenched and tempered (QT) steel was studied by using a single bolt joint-type fretting experiment. This experimental approach was selected to obtain realistic data on the fretting fatigue performance of the contact pairs (both coating-to-steel and coating-to-coating). Experimental results were completed with continuum-scale linear elastic finite element method (FEM) calculations.

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Thermally sprayed coatings for the valve industry

Cited by 4 publications

References 21 publications

Development of Near Net Shaped Coatings for Reduced Postprocessing Costs in Valves

Development of Near Net Shaped Coatings for Reduced Postprocessing Costs in Valves

Investigation of Novel Nano-carbide WC/CoCr Coatings Applied by HVAF

Fretting Behavior of WC-Co-Cr Coatings Against QT Steel in Bolted Joint

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