Method for forming thermal spray coating film of intermetallic compound, thermal spray coating film, method for producing metal product having spray coating film and glass-conveying roll

Abstract

A method for forming a thermal spray coating film, by forming a thermal spray coating film of an Al—Fe based intermetallic compound, from a mixture of an Al—Fe based intermetallic compound powder composed mainly of FeAl2 and a metal powder composed mainly of Fe, as feedstock, on the surface of a metal substrate.

What is claimed is: 
     
         1 . A method for forming a thermal spray coating film, comprising:
 forming a thermal spray coating film of an Al—Fe based intermetallic compound, on the surface of a metal substrate, from a mixture of an Al—Fe based intermetallic compound powder composed mainly of FeAl 2  and a metal powder composed mainly of Fe, as feedstock.   
     
     
         2 . The method according to  claim 1 , wherein a blend ratio of the intermetallic compound powder to the metal powder is from 70/30 to 80/20 by the weight ratio. 
     
     
         3 . The method according to  claim 1 , wherein a weight ratio (Al/Fe) of Al to Fe in the mixture is from 0.55 to 0.85. 
     
     
         4 . The method according to  claim 1 , wherein a weight ratio (Al/Fe) of Al to Fe in the intermetallic compound powder is from 0.90 to 1.15. 
     
     
         5 . The method according to  claim 1 , wherein a proportion of FeAl 2  in the intermetallic compound powder is at least 75 weight %. 
     
     
         6 . The method according to  claim 1 , wherein a proportion of Fe in the metal powder is at least 70 weight %. 
     
     
         7 . The method according to  claim 1 , wherein a constituent material of the surface of the metal substrate is iron or an iron-based alloy. 
     
     
         8 . The method according to  claim 1 , wherein the thermal spray coating film has a film-thickness of from 0.05 to 1.5 mm. 
     
     
         9 . A method for producing a metal product, comprising:
 forming a thermal spray coating film of an Al—Fe based intermetallic compound on the surface of a metal substrate by the method as defined in  claim 1 , to produce a metal product comprising the metal substrate having the thermal spray coating film.   
     
     
         10 . The method according to  claim 9 , wherein the metal product is a glass-conveying roll. 
     
     
         11 . A thermal spray coating film of an Al—Fe based intermetallic compound, which has a multi-phase structure in a scanning electron microscopic (SEM) image showing a cross-section of the thermal spray coating film of an Al—Fe based intermetallic compound. 
     
     
         12 . The thermal spray coating film according to  claim 11 , wherein a weight ratio (Al/Fe) of Al to Fe in the thermal spray coating film is from 0.55 to 0.85. 
     
     
         13 . The thermal spray coating film according to  claim 11 , which contains Al 2 O 3  particles having a size of less than 5 μm. 
     
     
         14 . The thermal spray coating film according to  claim 11 , wherein a distance between Al 2 O 3  particles being present within 50 μm from a surface layer of the thermal spray coating film, is at least 5 μm. 
     
     
         15 . A glass-conveying roll comprising a metal roll having the thermal spray coating film as defined in  claim 11  on its surface.