Bonding titanium to stainless steel

A method of making a stainless steel and titanium component assembly for implantation in living tissue, comprising the steps of:

• selecting a stainless steel part having a melting point;
• selecting a titanium part having a melting point;
• selecting a primary alloy particulate discrete particles comprised of a nickel alloy;
• selecting a secondary alloy particulate discrete particles comprised of a titanium alloy;
• forming a compact filler by combining said selected primary alloy particulate and said secondary alloy particulate in a randomly oriented mixture comprised of a 22% to 98% nickel portion and a remaining titanium portion;
• mechanically compacting said compact filler to form a compact filler layer less than 0.010 inches thick;
• positioning said 0.010 inches thick compact filler layer between said stainless steel part and said titanium part forming a component assembly;
• placing said component assembly in a non-reactive atmosphere;
• applying a force to said stainless steel part and said titanium part to place said compact filler layer in compression, thereby creating intimate contact between said stainless steel part, said compact filler layer, and said titanium part;
• heating said component assembly to a bonding temperature between said melting point of said compact filler layer and said melting point of said titanium part;
• holding said component assembly at said bonding temperature for a predetermined time to form a bond between said stainless steel part and said titanium part forming a bonded component assembly;
• cooling said bonded component assembly;
• and
• implanting said component assembly in a human body.

A method of making a stainless steel part and a titanium part component assembly for implantation in living tissue in which a filler is placed between the two parts to be bonded, applying a compressive force of 5 to 50 psi to said stainless steel part and to said titanium part so as to place said filler material in compression to form intimate contact between said stainless steel part and said titanium part and in which said component assembly, comprising said stainless steel part, said titanium part and said filler, is placed at a bonding temperature, for a predetermined time, wherein the improvement comprises:

• selecting said filler to be a compact filler comprised of a primary alloy particulate discrete particles comprised of a nickel alloy and a secondary alloy particulate discrete particles comprised of a titanium alloy;
• bonding said component assembly between 940° and 1260° C.;
• and
• implanting said component assembly in a human body.