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1291 |
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Wednesday, June 04, 2008, Room 05 3:40 PM Polymers, Environmental-Friendly Coatings, Non Destructive Testing Testing coatings directly on coated parts without destroying any additionally coated samples, polymer-based coatings and environmental-friendly coatings |
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New health and environmental-friendly iron based materials employed as binders for carbide powders used in thermal spraying |
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Stefan Zimmermann* / H.C. Starck GmbH, Germany Benno Gries / H.C. Starck GmbH, Germany Jürgen Fischer/ H.C. Starck GmbH, Germany |
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Cobalt containing carbide powders such as WC-Co and WC-Co-Cr for thermal spraying exist in numerous modifications varying in chemistry, carbide size, and production method. They are widely used for wear, erosion and corrosion protection in many industrial fields. However, for decades it has been well-known from the hard metal industry that WC and Co containing hard metals in breathable dust form can provoke severe lung diseases if inhaled. Recent examinations have proven that this toxicity can be significantly reduced if the Co is pre-alloyed by Fe. In thermal spraying employees are also dealing with Co containing carbides, for example in powder and coating production. Therefore, in order to reduce the hazards for health and environment, a new class of agglomerated and sintered carbide powders using Fe based binder materials has been developed and investigated. In the present study the powders were HVOF sprayed in order to examine the influence of their different composition and morphology on the microstructure and the properties of the coatings in comparison to standard materials. The experiments comprise microstructural examinations, wear and corrosion tests as well as solubility tests of constituents such as Co or Ni. |