Thermal barrier deposited directly on monocrystalline superalloys

Abstract

The invention relates to the field of superalloys coated in a thermal barrier. On a monocrystalline superalloy having the following composition by weight: 3.5% to 7.5% Cr, 0 to 1.5% Mo, 1.5% to 5.5% Re, 2.5% to 5.5% Ru, 3.5% to 8.5% W, 5% to 6.5% Al, 0 to 2.5% Ti, 4.5% to 9% Ta, 0.08% to 0.12% Hf, 0.08% to 0.12% Si, the balance to 100% being constituted by Ni and any impurities, a stabilized zirconia is deposited directly, the zirconia being stabilized with at least one oxide of an element selected from the group constituted by rare earths, or with a combination of a tantalum oxide and at least one rare earth oxide, or with a combination of a niobium oxide and at least one rare earth oxide.

1 . A method of depositing a thermal barrier on a monocrystalline superalloy, wherein said superalloy has following composition by weight: 3.5% to 7.5% Cr, 0 to 1.5% Mo, 1.5% to 5.5% Re, 2.5% to 5.5% Ru, 3.5% to 8.5% W, 5% to 6.5% Al, 0 to 2.5% Ti, 4.5% to 9% Ta, 0.08% to 0.12% Hf, 0.08% to 0.12% Si, the balance to 100% being constituted by Ni and any impurities, and wherein a stabilized zirconia is deposited directly on said superalloy, the zirconia being stabilized with at least one oxide of an element selected from the group constituted by rare earths, or with a combination of a tantalum oxide and at least one rare earth oxide, or with a combination of a niobium oxide and at least one rare earth oxide. 
   
   
       2 . A method according to  claim 1 , wherein said superalloy has the following composition by weight: 3.5% to 5.5% Cr, 0 to 1.5% Mo, 4.5% to 5.5% Re, 2.5% to 5.5% Ru, 4.5% to 6.5% W, 5% to 6.5% Al, 0 to 1.5% Ti, 5% to 6.2% Ta, 0.08% to 0.12% Hf, 0.08% to 0.12% Si, the balance to 100% being constituted by Ni and any impurities. 
   
   
       3 . A method according to  claim 1 , wherein said superalloy has the following composition by weight: 3.5% to 5.5% Cr, 0 to 1.5% Mo, 3.5% to 4.5% Re, 3.5% to 5.5% Ru, 4.5% to 6.5% W, 5.5% to 6.5% Al, 0 to 1% Ti, 4.5% to 5.5% Ta, 0.08% to 0.12% Hf, 0.08% to 0.12% Si, the balance to 100% being constituted by Ni and any impurities. 
   
   
       4 . A method according to  claim 1 , wherein said zirconia is stabilized with at least one oxide of an element selected from the group constituted by dysprosium, erbium, europium, gadolinium, samarium, ytterbium, yttrium, or with a combination of an oxide of tantalum and at least one oxide of an element in said group, or group, or with a combination of an oxide of niobium and at least one oxide of an element of said group. 
   
   
       5 . A method according to  claim 1 , wherein said zirconia is stabilized with an yttrium oxide. 
   
   
       6 . A part, the part being constituted by a monocrystalline superalloy having the following composition by weight: 3.5% to 7.5% Cr, 0 to 1.5% Mo, 1.5% to 5.5% Re, 2.5% to 5.5% Ru, 3.5% to 8.5% W, 5% to 6.5% Al, 0 to 2.5% Ti, 4.5% to 9% Ta, 0.08% to 0.12% Hf, 0.08% to 0.12% Si, the balance to 100% being constituted by Ni and any impurities, and wherein at least a portion of its surface is in direct contact with a zirconia stabilized with at least one oxide of an element selected from the group constituted by rare earths, or with a combination of a tantalum oxide and at least one rare earth oxide, or with a combination of a niobium oxide and at least one rare earth oxide, said zirconia acting as a thermal barrier. 
   
   
       7 . A turbine blade, comprising a part according to  claim 6 . 
   
   
       8 . A turbomachine, including a turbine blade according to  claim 7 .