| 摘要 |
Powder of particles, more than 95% by number of said particles exhibiting a circularity greater than or equal to 0.85, wherein said powder contains more than 99.8% of a rare earth oxide and/or of hafnium oxide and/or of yttrium aluminium oxide, as percentage by weight relative to the oxides, and has: - a median particle size D 50 of between 10 and 40 microns and a size dispersion index (D 90 - D 10)/D 50 of less than 3; - a percentage by number of particles having a size less than or equal to 5 µm which is less than 5%; - an apparent-density dispersion index (P < 50 -P)/P of less than 0.2, the cumulative specific volume of the pores which have a radius of less than 1 µm being less than 10% of the apparent volume of the powder, in which the percentiles Dn of the powder are the particle sizes corresponding to the percentages, by number, of n%, on the curve of cumulative distribution of the particle size of the powder, the particle sizes being classified in increasing order, the density P < 50 being the apparent density of the fraction of particles having a size less than or equal to D50, and the density P being the apparent density of the powder. |
