Method of making metal foil material for catalytic converters
AssigneeTexas Instruments Incorporated
InventorsSunil C. Jha, James A. Forster
Life of this patent
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Abstract
A metal foil substrate material 50 for catalytic converters 54 and method of making the material in which layers (10, 12, 14) of ferritic stainless steel and aluminum are solid state metallurgically bonded together forming a composite material 24. Such composite material 24 is further rolled to the final foil gauge with no heat treatment and then subjected to a thermal in situ reaction to form a resulting uniform solid solution foil material 50 with superior high temperature corrosion resistance.
Claims11
A method for making a foil substrate material having various metal constituents for catalytic converters comprising the steps of:
- providing a layer of a first material chosen from the group consisting of chromium containing ferrous metals with up to about 2 wt. percent aluminum and aluminum and aluminum alloys, sandwiching said layer of first material between first and second layers of a second material chosen from the group consisting of chromium containing ferrous metals with up to about 2 wt. percent aluminum and aluminum and aluminum alloys not chosen for the first material, metallurgically bonding said layers together by reducing the thickness of said layers thereby forming a multilayer composite material of said first and second materials, reducing the thickness of the composite material to the final desired thickness for the foil substrate material and heating said composite material in situ at a temperature between 900.degree. C. and 1200.degree. C. for a sufficient period of time to cause diffusion of the various metal constituents of said layers throughout the composite thereby providing a uniform solid solution material for the foil substrate.
A method for making a metallic foil substrate material for catalytic converters comprising the steps of:
- providing a first layer of a first material chosen from the group consisting of chromium containing ferrous metals with up to about 2 wt. percent aluminum and aluminum and aluminum alloys, sandwiching said first layer of said first material between first and second layers of a second material chosen from the group consisting of chromium containing ferrous metals with up to about 2 wt. percent aluminum and aluminum and aluminum alloys not chosen for the first material, pressure rolling the layers of metal material together with a reduction in thickness thereof for metallurgically bonding the layers together to form a composite multilayer material;
- further pressure rolling said multilayer composite to the final desired thickness for the foil substrate material, said further pressure rolling done without any thermal treatment which would cause the formation of intermetallic constituents of the first and second materials, and heating said composite material at a temperature between 900.degree. C. and 1200.degree. C. for a sufficient period of time to cause diffusion of metal constituents of said layers throughout the composite thereby providing a uniform solid solution material for the foil substrate.
Dependencies are inferred from the claim text.