DUPLEX TREATMENT OF MOLDS FOR DIE-CASTING

• Main Author: QUINTO, DENNIS T
• Format: Patent
• Language: English
• Published: 01.08.2016
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

This invention pertains to duplex treatment of steel alloy molds, whereby the first step is surface hardening of the mold surface by a suitable nitriding process, followed by a second step of Physical Vapor Deposition (PVD) process yielding a hard coating product with a particular design. The invention covers 1) the process of preparing or conditioning the as-received mold surface for duplex treatment, 2) the process of plasma nitriding with parameters that yield a nitride surface zone compatible with the subsequent PVD coating process, and 3) the composite product which comprises of a plasma nitride zone underlying the PVD coating with a certain compositional and microstructural architecture. A significant extension of mold life and performance in the manufacture of aluminum die-cast components is obtained by this invention.