Metal-Glass Composite Materials

1,163,286. Ornamenting. E. I. DU PONT DE NEMOURS & CO. 8 Nov., 1966, No. 49900/66. Heading B6G. [Also in Division C1] A non-porous metal substrate carrying within its surface a particulate material consisting of glass, a glass-metal mixture, or a glass metal composite, the particulate material being impressed into the substrate to a degree such that it is firmly embedded therein with its outwardly facing surfaces substantially coplanar with the surface of the substrate, is produced by heating the glass or glass-metal to a temperature at which the glass viscosity is in the range 102À8- 107 poises, then the metal in the glass-metal mixture to sintering temperature, finally the metal substrate to a temperature at which its surface becomes soft enough to accept the particulate material when compressive force is applied, then, before substantial cooling occurs applying the compressive force to the particulate material and to the metal substrate with the particulate material distributed over it, and then cooling the metal substrate with the particulate material embedded therein. Both sides of a metal substrate may be so coated, or the same or different coloured glass compounds may be applied by superposing a plurality of layers one over the other as by a silk screen process, each being hot-rolled. The three heating steps may be applied in sequence or, when their temperatures overlap, concurrently. Suitable metal substrates are aluminium, magnesium, zinc, and alloys thereof, low carbon steel, stainless steel, copper, nickel, titanium and alloys of copper, nickel or titanium. In a typical example (1) a lead borosilicate glass containing iron cobalt black sintered inorganic pigment (viscosity 104 poises) ground to a fineness of 100% through a 100-mesh screen is applied with methanolthinned epoxy-resin adhesive on an aluminium substrate and heat-rolled immediately at 580‹ C. In Example 5 glass decalcomania in the form of an antique automobile design is applied to an aluminium sheet, the maturing temperature of the glass being 540‹ C. at which the viscosity is 104 poises, the decalcomania being applied to the metal substrate, heated to a temperature of 580‹ C. and immediately hot-rolled. In Example 5a a similar decalcomania is applied to a metallic nickel strip, heated to 800‹ C. for 10 mins. and immediately hot-rolled.