Composite casting method

Claim 1

THE METHOD OF PRODUCING A CASTING HAVING A SURFACE COATED WITH HARD FACING MATERIAL, COMPRISING: A. DEPOSITING A COATING OF SELECTED THICKNESS OF METALLOID HARD FACING MATERIAL SELECTED FROM THE GROUP CONSISTING OF TUNGSTEN, COBALT, MOLYBDENUM, TUNGSTEM CARBIDE, COBALT CARBIDE,MOLYBDENUM CARBIDE, SILICON CARBIDE,AND TITANIUM CARBIDE ON A PORTION OF A MOLD CONSTITUTING AT LEAST A. PART OF A MOLD CAVITY, THE METALLOID COATING HAVING AN EXPOSED IRREGULAR SURFACE, B. DEPOSITING APROTECTIVE LAYER OF A METAL SELECTED FROM THE GROUP CONSISTING OF THE ALUMINUM FAMILY AND THE COPPER FAMILY ON THE EXPOSED IRREGULAR SURFACE OF THE METALLOID COATING IN INTERLOCKING RELATIONSHIP THEREWITH, THE METAL PROTECTIVE LAYER HAVING AN IRREGULAR SURFACE EXPOSED TO THE MOLD CAVITY, C. FEEDING MOLTEN BASIS METAL SELECTED FROM THE GROUP CONSISTING OF ALLOYS OF ALUMINUM, MAGNESIUM, AND ZINC INTO THE MOLD CAVITY UNDER SUFFICIENT PRESSURE TO FORM AN INTERLOCKING RELATIONSHIP WITH THE IRREGULAR SURFACE OF THE PROTECCTIVE METAL LAYER, D. THE METAL OF THE PROTECTIVE LAYER HAVING HIGHER THERMAL CONDUCTIVITY THAN THE METALLOID MATERIAL TO DISTRIBUTE THE HEAT OF THE BASIS METAL RAPIDLY AROUND THE METALLOID MATERIAL FROM THE POINT OF IMPACT OF THE INJECTED BASIS MATERIAL AGAINST THE PROTECTIVE LAYER, THE METAL OF THE PROTECTIVE LAYER HAVING GREATER DUCTILITY THAN THE METALLOID MATERIAL IN ORDER TO ABSORB THERMAL STRESSES WITH MINIMUM TRANS-

Claim 2

THE METHOD OF PRODUCING A CASTING HAVING A SURFACE COATED WITH HARD FACING MATERIAL, COMPRISING: A. DEPOSITING A COATING OF SELECTED THICKNESS OF METALLOID HARD FACING MATERIAL SELECTED FROM THE GROUP CONSISTING OF TUNGSTEN, COBALT, MOLYBDENUM, TUNGSTEM CARBIDE, COBALT CARBIDE,MOLYBDENUM CARBIDE, SILICON CARBIDE,AND TITANIUM CARBIDE ON A PORTION OF A MOLD CONSTITUTING AT LEAST A. PART OF A MOLD CAVITY, THE METALLOID COATING HAVING AN EXPOSED IRREGULAR SURFACE, B. DEPOSITING APROTECTIVE LAYER OF A METAL SELECTED FROM THE GROUP CONSISTING OF THE ALUMINUM FAMILY AND THE COPPER FAMILY ON THE EXPOSED IRREGULAR SURFACE OF THE METALLOID COATING IN INTERLOCKING RELATIONSHIP THEREWITH, THE METAL PROTECTIVE LAYER HAVING AN IRREGULAR SURFACE EXPOSED TO THE MOLD CAVITY, C. FEEDING MOLTEN BASIS METAL SELECTED FROM THE GROUP CONSISTING OF ALLOYS OF ALUMINUM, MAGNESIUM, AND ZINC INTO THE MOLD CAVITY UNDER SUFFICIENT PRESSURE TO FORM AN INTERLOCKING RELATIONSHIP WITH THE IRREGULAR SURFACE OF THE PROTECCTIVE METAL LAYER, D. THE METAL OF THE PROTECTIVE LAYER HAVING HIGHER THERMAL CONDUCTIVITY THAN THE METALLOID MATERIAL TO DISTRIBUTE THE HEAT OF THE BASIS METAL RAPIDLY AROUND THE METALLOID MATERIAL FROM THE POINT OF IMPACT OF THE INJECTED BASIS MATERIAL AGAINST THE PROTECTIVE LAYER, THE METAL OF THE PROTECTIVE LAYER HAVING GREATER DUCTILITY THAN THE METALLOID MATERIAL IN ORDER TO ABSORB THERMAL STRESSES WITH MINIMUM TRANS-

Claim 3

The method of producing a casting having a surface coated with hard facing material, comprising: a. depositing a coating of selected thickness of metalloid hard facing material selected from the group consisting of tungsten, cobalt, molybdenum, tungsten carbide, cobalt carbide, molybdenum carbide, silicon carbide, and titanium carbide on a portion of a mold constituting at least a part of a mold cavity, the metalloid coating having an exposed irregular surface, b. depositing a protective layer of a metal selected from the group consisting of the aluminum family and the copper family on the exposed irregular surface of the metalloid coating in interlocking relationship therewith, the metal protective layer having an irregular surface exposed to the mold cavity, c. feeding molten basis metal selected from the group consisting of alloys of aluminum, magnesium, and zinc into the mold cavity under sufficient pressure to form an interlocking relationship with the irregular surface of the protective metal layer, d. the metal of the protective layer having higher thermal conductivity than the metalloid material to distribute the heat of the basis metal rapidly around the metalloid material from the point of impact of the injected basis material against the protective layer, the metal of the protective layer having greater ductility than the metalloid material in order to absorb thermal stresses with minimum transmission thereof to the metalloid material, the protective layer being from three to twenty times the thickness of the metalloid material to provide a thermal gradient across its thickness to delay transmission of heat to the metalloid material, and the metal of the protective layer having a melting point lower than that of the metalloid but at least as high as that of the basis metal to preclude fusing of the protective layer, the combination of properties of the thermal layer preventing thermal damage to the metalloid coating from thermal shock of the casting procedure, e. solidifying the casting within the cavity, and removing the casting from the cavity with the metal layer and the metalloid coating being integral parts of the casting, the metalloid coating forming a hard facing on at least a portion of a surface of the casting.

Claim 4

The method of producing a casting having a surface coated with hard facing material, comprising: a. depositing a coating of selected thickness of metalloid hard facing material selected from the group consisting of tungsten, cobalt, molybdenum, tungsten carbide, cobalt carbide, molybdenum carbide, silicon carbide, and titanium carbide on a portion of a mold constituting at least a part of a mold cavity, the metalloid coating having an exposed irregular surface, b. depositing a protective layer of a metal selected from the group consisting of the aluminum family and the copper family on the exposed irregular surface of the metalloid coating in interlocking relationship therewith, the metal protective layer having an irregular surface exposed to the mold cavity, c. feeding molten basis metal selected from the group consisting of alloys of aluminum, magnesium, and zinc into the mold cavity under sufficient pressure to form an interlocking relationship with the irregular surface of the protective metal layer, d. the metal of the protective layer having higher thermal conductivity than the metalloid material to distribute the heat of the basis metal rapidly around the metalloid material from the point of impact of the injected basis material against the protective layer, the metal of the protective layer having greater ductility than the metalloid material in order to absorb thermal stresses with minimum transmission thereof to the metalloid material, the protective layer being from three to twenty times the thickness of the metalloid material to provide a thermal gradient across its thickness to delay transmission of heat to the metalloid material, and the metal of the protective layer having a melting point lower than that of the metalloid but at least as high as that of the basis metal to preclude fusing of the protective layer, the combination of properties of the thermal layer preventing thermal damage to the metalloid coating from thermal shock of the casting procedure, e. solidifying the casting within the cavity, and removing the casting from the cavity with the metal layer and the metalloid coating being integral parts of the casting, the metalloid coating forming a hard facing on at least a portion of a surface of the casting.