1. PLASMA SPRAYED COATINGS OF MECHANOFUSED ALUMINA-STEEL PARTICLES
- Author
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Hélène Ageorges, Pierre Fauchais, Alain Grimaud, Axe 2 : procédés de traitements de surface, Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,Dense plasma focus ,plasma sprayed splat ,alumina steel particle ,Composite number ,Nozzle ,General Medicine ,Plasma ,engineering.material ,law.invention ,Plasma torch ,law ,engineering ,Cast iron ,Composite material ,Forming gas ,mechanofusion ,Pyrometer ,plasma sprayed coating - Abstract
International audience; Steel particles (Fe + 19 wt% Cr and 11 wt% Ni) with a size distribution in the range between 50 and 100 μm were coated with pure α-alumina (99.99%) particles whose mean size was 0.6 μm using a mechanofusion process. It was possible to obtain particles with alumina shells with a mean thickness of 2−4 μm. EDS analysis showed that, according to the detection limit, no alumina was imbedded in the steel core and reciprocally no steel was included in the alumina shell. The composite powder was then plasma sprayed using a PTF4 type plasma gun (nozzle internal diameter 7 mm) with the internal injection of the powder 3 mm upstream of the nozzle exit. The arc current was 500 A and plasma forming gas mixture was 53 slm Ar and 7 slm H2. The coatings were sprayed on cast iron samples (diameter: 25 mm, thickness: 5 mm) located on a rotating substrate holder (110 mm diameter). The plasma torch was moved parallel to the holder axis. The substrates were preheated with the plasma gun and their surface temperature was controlled by air jets monitored by an IR monochromatic pyrometer. The coatings showed a uniform distribution of alumina in the steel matrix for two substrate preheating temperatures of 300 and 550° C.
- Published
- 2023