Roll comprising an abradable coating
AssigneeVesuvius France
InventorsJean-denis Nicolas, Gilbert Rancoule, Christian Berry
Life of this patent
Estimating the term…
Abstract
A protective and abradable coating composition is suitable for application on rolls and more particularly for application on conveyor rolls. The abradable coating is suitable for use in high temperature applications. Rolls incorporating the coating may be produced and used according to disclosed processes and procedures. Application of the composition to rolls reduces corrosion by aluminium melt, and enables the removal of built-up substances by friction. The life time of the roll is thereby increased.
Claims11
Conveyor roll comprising a cylindrical exterior surface, wherein the conveyor roll comprises at least a layer of a coating, wherein the coating comprises
- a) 83-98 wt % of an aggregate comprising particles of a material selected from the group consisting of hydrolyzed Si3N4, SiC or SiAlON and a mixture thereof,
- b) 2-17 wt % of submicronic particles comprising a material selected from the group consisting of Al2O3, SiO2, ZrO2, CeO2, Y2O3 and a mixture thereof, and
- wherein the coating is heated at a temperature of at least 800° C. for at least three hours.
Process for manufacturing a conveyor roll comprising the steps of:
- a) providing a roll made of a material selected from the group consisting of fused silica, mullite, sillimanite, alumina, SiC matrix and metal, wherein the roll comprises a core and a cylindrical exterior surface;
- b) applying on at least a portion of a surface of the roll, a composition comprising
- a) 50-75 wt % of an aggregate comprising particles of a material selected from the group consisting of hydrolyzed Si3N4, SiC, SiAlON and a mixture thereof,
- b) 1.5-10 wt % of submicronic particles comprising a material selected from the group consisting of Al2O3, SiO2, ZrO2, CeO2, Y2O3 and a mixture thereof, and
- c) 15-48.5 wt % H2O,
- characterized in that the particles of Si3N4, SiC, SiAlON and a mixture thereof have a specific surface area (BET) in the range from and including 0.5 m2/g to and including 8 m2/g;
- c) drying the roll;
- and
- d) heating the roll at 800° C. for at least 3 hours.
Dependencies are inferred from the claim text.