CRN coated die-casting tools for casting low aluminum iron alloys and method of making same
AssigneeAluminum Company of America
InventorsNeville Whittle, Joseph P. Harenski, Norman J. Panseri
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Abstract
Steel tooling for die-casting low iron content aluminum alloys is surface treated with a layer of CrN applied to a thickness of at least 4 microns, and preferably 5-10 microns, by physical vapor deposition (PVD), and preferably a steered are evaporation PVD process. The CrN protects the steel tooling from dissolution and erosion by the highly active molten aluminum.
Claims19
A die-casting tool having a desired surface configuration suitable for die-casting aluminum and aluminum alloys with an iron content of less than about 0.6% by weight, said die-casting tool comprising:
- a steel substrate having a desired tool surface configuration and a surface coating comprising a CrN deposit on the desired surface configuration of said substrate, the coating having a thickness of at least about four microns and thermal shock resistance which resists defects in the coating through which the aluminum or aluminum alloy attacks said steel substrate.
The method of coating steel tooling for die-casting aluminum and aluminum alloys with an iron content of less than about 0.6% iron, said method comprising the steps of:
- cleaning said steel tooling, and applying a coating of CrN to a thickness of at least 4 microns using a physical vapor deposition process.
Dependencies are inferred from the claim text.