Target for vaporizing under an electron beam, a method of fabricating it, a thermal barrier and a coating obtained from a target, and a mechanical part including such a coating

A ceramic coating composition, comprising:

• a bonding underlayer;
• a first ceramic layer based on yttrified zirconia having a molar content of yttrium oxide lying in the range 4% to 12%;
• and
• a second ceramic layer formed by a thermal barrier of low thermal conductivity and high thermomechanical strength, including
• a composite target in the form of a bar made of ceramic powders, the target comprising zirconia and at least one zirconia stabilizer, said zirconia stabilizer being included at a molar content lying in a range of 2% to 30%, wherein after sintering of the target, said zirconia in the target contains more than 90% of a monoclinic phase, the barrier is formed by evaporating the composite target under an electron beam, and the barrier is deposited on a substrate made of superalloy,
• wherein said first ceramic layer is situated between said bonding underlayer and said second ceramic layer.