GROUP IIIA ELEMENT FLUORIDE-CONTAINING COATINGS FOR USE IN IMPROVING CORROSION RESISTANCE OF MEMBERS TO BE EXPOSED TO CORROSIVE HALOGEN SPECIES-CONTAINING ATMOSPHERE, AND COATED MEMBERS HAVING SUCH COATINGS

摘要

PURPOSE: To provide a fluoride-containing coating having high corrosion resistance, and a coated member. CONSTITUTION: The Group IIIA element fluoride-containing coating comprises a Group IIIA element fluoride phase which contains at least 50 % of a crystalline phase of the orthorhombic system belonging to space group Pnma, wherein the intensity ratio I(111)/I(020) of the diffraction intensity I(111) of plane index(111) to the diffraction intensity I(020) of plane index (020) of orthorhombic crystals in the Group IIIA element fluoride phase is at least 0.3, wherein the Group IIIA element primarily comprises at least one element selected from the group consisting of Sm, Eu, Gd, Tb, Dy, Ho, Er, Y, Tm, Yb and Lu, wherein the Group IIIA element fluoride-containing coating comprises crystal grains having a size of at least 1μm on surface observation, wherein the Group IIIA element fluoride-containing coating has a thickness of 1 to 500μm, wherein the total content of Group IA elements and iron family elements other than incidental impurities of oxygen, nitrogen and carbon is up to 100 ppm, wherein the Group IIIA element fluoride-containing coating is prepared by depositing solid particles or molten droplets, wherein the solid particles or molten droplets are comprised of the Group IIIA element fluoride, wherein the solid particles or molten droplets are prepared from a crystalline powder, wherein the Group IIIA element fluoride-containing coating is deposited under atmospheric pressure, wherein the Group IIIA element fluoride-containing coating is deposited on a substrate while heating the substrate, and wherein the Group IIIA element fluoride-containing coating is deposited on a substrate while heating the substrate at a temperature of at least 80 deg.C.