US 4,055,975 AGranted

Precision forging of titanium

AssigneeLockheed Aircraft Corporation

InventorsTibor Serfozo, Rod F. Simenz

Life of this patent

Estimating the term…

Loading patent…

Abstract

A process of precision forging of titanium or a titanium alloy in which the forging stock and a segmented die are first heated to forging temperature while separated, and are then assembled together and heated again to that temperature, with the stock being covered by a protective coating preferably containing glass grit, and the die sections being coated with lubricant. The heated die and contained heated forging stock are then inserted in a heated holder and the stock subjected to forging force, to partially but not completely deform the stock to the shape of the die cavity, following which the die and stock are separated and the stock allowed to cool, flashing is removed from the stock, the die is cleaned, the die and stock are recoated and then reheated separately and then together, and the stock is forged again to assume more closely the shape of the die cavity. The series of recoating, heating and forging steps are performed at least twice, and may be repeated one or more additional times as necessary to completely forge the part to the die cavity shape.

Claims18

Dependent claims

The titanium forging process that comprises:

preparing a quantity of titanium or titanium alloy stock shaped to fit within a cavity in a segmented zero draft die and having a volume approximately equal to that of a forged part to be manufactured in the die;
applying a protective coating to said stock;
heating said coated stock and said segmented zero draft die while separted to approximately a predetermined optimum forging temperature for said stock at least as high as about 1200.degree. F;
coating all segments of said die with a lubricant before positioning the stock therein;
positioning the heated stock in the heated die;
heating the die and contained stock further after assembly together and as necessary to give the combination said forging temperature;
applying forging force to said heated segmented die to deform the heated stock partially, but not completely, toward the shape of said cavity;
separating the sections of said segmented die and removing the partially forged stock therefrom;
applying a protective coating again to said partially forged stock;
reheating said partially forged stock and said segmented die while separated to said forging temperature;
coating said die segments again with a lubricant before placing the stock therein for a second time;
repositioning said heated partially forged stock in the segmented die;
reheating the die and stock together;
applying forging force again to the heated die to further deform the heated partially forged stock toward the shape of said cavity;
and
separating the die sections and removing the forged stock therefrom.

13 more elements

The titanium forging process that comprises:

preparing a quantity of titanium or titanium alloy stock shaped to fit within a cavity in a segmented die and having a volume approximately equal to that of a forged part to be manufactured in the die;
coating all of the surfaces of said stock with a layer of material including glass grit in a liquid carrier, which material is capable of protecting said surfaces of the stock against oxidation when heated to the forging temperature of the stock;
heating said coated stock and said segmented die while separate to appoximately the forging temperature of the stock;
coating the heated die with a graphite suspension lubricant;
positioning the heated stock in the heated die;
heating the die and contained stock together to said forging temperature;
preheating a die holder to a temperature several hundred degrees above ambient temperature but much lower than the temperature of the stock and segmented die;
then placing the heated die and the contained stock together in said holder;
applying forging force to said heated segmented die in said holder to deform the stock partially, but not completely toward the shape of said cavity;
removing the die and stock from the holder and separating the sections of the segmented die and removing the partially forged stock therefrom;
allowing the stock to cool;
removing flashing from the stock;
applying a second coating of heat resistant glass grit in a liquid carrier to the srufaces of said partially forged stock;
cleaning the surfaces of the sections of the segmented die;
reheating the partially forged coated stock and the segmented die while separate to essentially said forging temperature;
recoating the heated sections of the segmented die with graphite suspension lubricant;
repositioning the partially forged stock in the segmented die;
reheating the die and contained stock together;
placing the die and stock together in said holder while the latter is at a temperature several hundred degrees above ambient but much lower than the temperature of the die and stock;
applying forging force again to the die while in said holder to further deform the stock toward the shape of said cavity;
and
removing the die sections and forged stock from the holder and separating the die sections from the stock.

19 more elements

Dependencies are inferred from the claim text.