Manufacturing method for a ceramic to metal seal

• US 6,986,453 B2
• Filed: 11/13/2003
• Issued: 01/17/2006
• Est. Priority Date: 11/13/2003
• Status: Active Grant

• Current Assignee: Alfred E. Mann Foundation For Scientific Research
• Original Assignee: Alfred E. Mann Foundation For Scientific Research
• Inventors: Schnittgrund, Gary D., Jiang, Guangqiang, Purnell, Kate E.
• Primary Examiner(s): EDMONDSON, LYNNE RENEE
• Application Number:
  US10/714,193
• Publication Number:
  US 20050103825A1
• Time in Patent Office: 796 Days
• Field of Search: 228/122.1, 228/124.1, 228/124.6, 228/234.1, 228/246
• US Class Current: 228/122.1
• CPC Class Codes: B23K 20/233 without ferrous layer
• CPC Class Codes: C04B 2235/6581 Total pressure below 1 atmosphere, e.g. vacuum
• CPC Class Codes: C04B 2237/123 based on iron group metals, e.g. steel
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 2237/346 Titania or titanates
• CPC Class Codes: C04B 2237/348 Zirconia, hafnia, zirconates or hafnates
• CPC Class Codes: C04B 2237/403 Refractory metals
• CPC Class Codes: C04B 2237/52 Pre-treatment of the joining surfaces, e.g. cleaning, machining
• CPC Class Codes: C04B 2237/708 of one or more of the interlayers
• CPC Class Codes: C04B 35/645 Pressure sintering
• CPC Class Codes: C04B 37/023 characterised by the interlayer used C04B37/028 takes precedence

Abstract

The invention is a method of bonding a ceramic part to a metal part by heating a component assembly comprised of the metal part, the ceramic part, and a very thin essentially pure interlayer material of a compatible interlayer material placed between the two parts and heated at a temperature that is greater than the temperature of the eutectic formed between the metal part and the metal interlayer material, but that is less than the melting point of either the interlayer material, the ceramic part or the metal part. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a hermetic and strong bond between the ceramic part and the metal part. The bonded component assembly is optionally treated with acid to remove any residual free nickel and nickel salts, to assure a biocompatible component assembly for implantation in living tissue.

Claims

1. A method of bonding a Ti-6Al-4V metal part to a ceramic part making a hermetically sealed component assembly for implantation in living tissue, comprising the steps of:

selecting a ceramic part from the group consisting of biocompatible and corrosion resistant ceramics;

positioning an essentially pure nickel foil between said ceramic part and said Ti 6Al-4V metal part;

applying a force to said ceramic part and said metal part so as to place said pure nickel foil in compression;

placing said component assembly in a non-reactive atmosphere;

heating said component assembly to between approximately 1728° and

2012°

F. for between approximately 5 and 60 minutes; and

cooling said component assembly.

2. A method of banding a ceramic part to a metal part to form a component assembly for placement in living tissue in which an interlayer material is placed between the two parts to be bonded, applying a compressive force of 2 to 500 psi to said ceramic part and said metal part so as to place said interlayer material In compression to form intimate contact between said ceramic part, said metal part and said interlayer material, said interlayer material being a metal which forms a eutectic alloy with said metal part, said eutectic alloy consisting of metals comprising said metal part and said interlayer material and having a eutectic temperature that is lower than the melting point of said metal or of said interlayer material, and in which said component assembly, comprising said ceramic part, said metal part and said pure interlayer material, is placed at a bonding temperature, for a predetermined time, that is less than the melting point of said metal part, said ceramic part or said interlayer material, but where said bonding temperature is greater than the melting point temperature of said eutectic alloy, selecting said ceramic part from the group consisting of alumina, mania, zirconia, stabilized-zirconia, partially-stabilized zirconia, tetragonal zirconia, magnesia-stabilized zirconia, ceria-stabilized zirconia, yttria-stabilized zirconia, and calcia-stabilized zirconia, selecting said metal part from the group consisting of titanium and titanium alloys,

wherein the improvement comprises:

selecting said interlayer material to be essentially pure nickel; and

selecting said bonding temperature between approximately 1728° and

2012°

F.