Sintered abrasive particles, method of making the same, and abrasive articles including the same

Patent metadata

Field	Value
Publication number	US-10400146-B2
Application number	US-201414782475-A
Country	US
Kind code	B2
Filing date	Mar 27, 2014
Priority date	Apr 5, 2013
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A method of making sintered abrasive particles includes passing alumina precursor particles through a flame under conditions such that they are converted to alpha alumina. The precursor particles comprise a precursor of alpha alumina and have an average particle size of less than or equal to 500 microns. Sintered abrasive particles have a cellular microstructure comprising alpha alumina crystal grains of alpha alumina having a maximum dimension of less than about 3 microns are also disclosed. The sintered abrasive particles have an average particle size of less than or equal to 500 microns, and are essentially free of seed particles and alpha alumina grain size modifiers. Abrasive articles comprising a binder and a plurality of the sintered abrasive particles are also disclosed.

First claim

What is claimed is:

1. A method of making sintered abrasive particles, the method comprising:
passing precursor particles vertically downward through a flame along its longitudinal axis under conditions such that they are converted into the sintered abrasive particles, wherein the precursor particles comprise a calcined precursor of alpha alumina, and wherein the precursor particles have an average particle size of less than or equal to 500 microns.

2. The method of claim 1 , wherein the sintered abrasive particles comprise alpha alumina having a cellular microstructure, and the alpha alumina has an areal porosity of less than or equal to 5 percent, as measured using image analysis by cross-section at 10,000 times magnification.

3. The method of claim 1 , wherein the precursor particles contain, on a weight basis, less than 0.1 percent by weight of seed particles.

4. The method of claim 1 , wherein the precursor particles contain, on a weight basis, less than 0.1 percent by weight of alpha alumina grain size modifiers.

5. The method of claim 1 , wherein the sintered abrasive particles comprise shaped abrasive particles.

6. The method of claim 1 , wherein the precursor particles have a shape corresponding to a mold cavity used to shape it.

7. The method of claim 1 , wherein the sintered abrasive particles have a cellular microstructure comprising alpha alumina crystal grains, and wherein the alpha alumina crystal grains have a maximum dimension of less than about 3 microns.

8. The method of claim 1 , wherein the sintered abrasive particles consist essentially of alpha alumina.

Assignees

• 3M Innovative Properties Co

Inventors

• Erickson Dwight D
• Rosenflanz Anatoly Z

Classifications

• C04B2235/3218

  Aluminium (oxy)hydroxides, e.g. boehmite, gibbsite, alumina sol · CPC title

• C04B35/6268

  characterised by the applied pressure or type of atmosphere, e.g. in vacuum, hydrogen or a specific oxygen pressure · CPC title

• C04B35/62665

  Flame, plasma or melting treatment · CPC title

• C04B35/1115

  Minute sintered entities, e.g. sintered abrasive grains or shaped particles such as platelets (abrasives C09K3/14) · CPC title

• C01P2004/45

  Aggregated particles or particles with an intergrown morphology · CPC title