HIGHLY PURE POWDER INTENDED FOR THERMAL SPRAYING

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.

主权项

1. A powder formed of particles, more than 95% by number of said particles exhibiting a circularity of greater than or equal to 0.85, said powder comprising more than 99.8% of a rare earth metal oxide and/or of hafnium oxide and/or of an yttrium-aluminum oxide, as percentage by weight on the basis of the oxides, and having:
a median particle size D50 of between 10 and 40 microns and a size dispersion index (D90−D10)/D50 of less than 3; a percentage by number of particles having a size of less than or equal to 5 μm which is less than 5%; a bulk density dispersion index (P<50−P)/P of less than 0.2, the cumulative specific volume of the pores having a radius of less than 1 μm being less than 10% of the bulk volume of the powder, in which the Dn percentiles of the powder are the particle sizes corresponding to the percentages, by number, of n %, on the cumulative distribution curve of the size of the particles of the powder, the particle sizes being classified by increasing order, the density P<50 being the bulk density of the fraction of the particles having a size of less than or equal to D50, and the density P being the bulk density of the powder.