CPC C23C 24/085 (2013.01) [C04B 41/0018 (2013.01); C04B 41/0072 (2013.01); C04B 41/4545 (2013.01); B82Y 40/00 (2013.01); F01D 11/122 (2013.01); F05D 2230/90 (2013.01); F05D 2240/55 (2013.01); F05D 2300/2118 (2013.01)] | 13 Claims |
1. A process for manufacturing a substrate coated with an abradable layer, the substrate being a turbomachine part and the process comprising:
forming the abradable layer on a separate substrate comprising a powder composition comprising at least micrometric ceramic particles having a number-average form factor greater than or equal to 3, a mass content of said micrometric ceramic particles in the powder composition being greater than or equal to 85%, the form factor of a particle being defined as the ratio [largest dimension of the particle]/[largest cross-sectional dimension of the particle], by heating said micrometric ceramic particles, as well as any nanometric ceramic particles that may be present, to a first temperature T1 greater than or equal to 600° C. and while the assembly is brought to the first temperature T1, increasing a compression pressure until it reaches, at a first time t1, a plateau at a value Pc which corresponds to the compression pressure to be applied during the sintering of the powder composition; then
increasing the temperature of the powder composition and the separate substrate to the sintering temperature Tf reached at a second time t2; then
maintaining the sintering temperature Tf and the compression pressure Pc until the third time t3 to obtain the abradable layer; and
separating the abradable layer from the separate substrate;
depositing the abradable layer thus formed on a surface of the substrate, and
bonding the abradable layer thus deposited on the surface of the substrate wherein a temperature imposed during sintering, a sintering time and a compression pressure applied are selected so as to obtain a volume porosity rate of the abradable layer greater than or equal to 20%.
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