Protective coating for concrete delivery system components
View Patent ↗The present invention relates to a component of a concrete delivery system comprising a substrate made of relatively thin gauge carbon steel or aluminum, and a protective coating of amorphous, nano or near-nanoscale steel, or mixtures thereof, overlying the substrate, wherein the coating may be formed by thermal deposition process from multi-component glass forming steel alloys. The protective coating may also be heat treated to increase wear life.
1. A method of coating a concrete delivery component comprising:
providing a substrate comprising aluminum, for a concrete delivery component having a surface;
providing a multi-component alloy comprising more than 50% by weight Fe plus Cr, Mo, W, Mn, Si, B and C having a critical cooling rate for metallic glass formation of less than 10 5 K/s and a melting point in the range of 800° C. to 1500° C.; and
thermally depositing said multi-component alloy onto at least a portion of said substrate to form a protective coating, wherein said protective coating includes α- Fe and γ- Fe phases along with combinations of carbides, oxides and borides and is a metallic glass wherein at least a portion of said alloy has a combination of structural association sizes according to the following: (i) 5 to 100 Angstroms, (ii) 10 to 150 nm, and (iii) 150 nm to 1000 nm
wherein said size range of 150 nm to 1000 nm is present at a level of at least 50% by volume of said protective coating, said coating has a hardness of 64 to 80 Rockwell C, and the interface between said substrate and said multi-component alloy exhibits a bond strength in the range of 5,000 to 10,000 psi.
2. The method of claim 1 further comprising:
devitrifying at least a portion of said protective coating.
3. The method of claim 2 wherein said devitrification comprises:
heating said protective coating and said substrate at a temperature of about 400° C. to about 800° C. in the range of 5 minutes to 2 hours.
4. The method of claim 1 wherein said substrate comprises a chute.
5. The method of claim 1 wherein said substrate comprises a mixing drum.