%0 Journal Article %A Valette, S. %A Denoirjean, Alain %A Lefort, Pierre %A Fauchais, Pierre %D 2003 %I Begell House %N 2 %P 11 %R 10.1615/HighTempMatProc.v7.i2.100 %T INFLUENCE OF DC PLASMA PREHEATING ON OXIDE LAYERS FORMED BY FURNACE HEATING ON LOW CARBON STEEL SUBSTRATES AND RESULTING ADHESION/COHESION OF ALUMINA COATINGS %U https://www.dl.begellhouse.com/journals/57d172397126f956,6b6a11ba3e975d5b,54a381d2022fce94.html %V 7 %X In plasma spraying the preheating of low carbon steel substrates (X40) with a rough surface resulting from grit blasting, has received an increased interest because it promotes the adhesion and cohesion (A/C) of alumina coatings. Earlier works have reported the generation of a duplex Fе3O4/Fе2O3 layer after preheating by the d.c. plasma jet. Improved A/C values were obtained for an increase in Fе3O4 content in the oxide layer. Much improved adherence values were achieved with alumina spayed on Fe1-xO layers. In this case, the Adhesion/cohesion values obtained on smooth substrate (Ra ~ 0.1 mm) were good (~ 40 MPa) and close to those obtained on rough ones (Ra ~ 5 mm). First the time evolution of the Fe1-xO layer thickness and morphology produced in a controlled atmosphere furnace was studied. Then the influence of the plasma preheating of the wilstite layers was studied by SEM, and XRD analyses. XRD analysis results indicated a slight variation in the oxide phases depending on the preheating cycles. Fе3O4 was found to increase when a decomposition of Fe1-xO into Fе3O4 was observed. %8 2003-06-01