Isothermal metal forming

A method for forming titanium metals which provides the advantages of beta processing while avoiding the loss of ductility and the increase in grain size which is common to conventional beta processing, said process being carried out in apparatus which includes electrode means for supporting the workpiece, a forming tool of a refractory metal or refractory alloy and means by which said forming tool can be so biased against said workpiece and toward said forming tool as to exert a pressure of controlled magnitude on said workpiece and said method comprising the steps of:

• heating both that region of a titanium metal workpiece adjacent the forming tool and that portion of the forming tool adjacent the workpiece by connecting said workpiece across an electrical power source through the forming tool and the workpiece supporting electrode means;
• so regulating the pressure applied to the workpiece by the forming tool and the flow of current through the workpiece as to maintain the temperature of the alloy above its beta transus but below its solidus temperature;
• and effecting a translation of the workpiece relative to the forming tool to produce in that portion of the workpiece between the forming tool and the workpiece supporting electrode means a localized zone in which the workpiece is in a plastic and flowable condition and can therefore be readily deformed to alter its configuration and which will proceed along the workpiece and will exist in any region thereof only for a period of time measured in seconds.

A method for the solid state forming of a sheet metal workpiece into a component having two, integral, angularly disposed legs with apparatus which includes an electrode means for supporting the workpiece, a rotatable, pressure applying electrode of a refractory metal or a refractory alloy, and means by which said rotatable electrode can be so biased toward said workpiece supporting electrode means as to exert a pressure of a predetermined magnitude on said workpiece, said method comprising the steps of:

• confining one longitudinally extending, leg forming portion of said workpiece between tooling means with a second, longitudinally extending leg portion of the workpiece unsupported and protruding beyond those surfaces of the tooling means facing said pressure applying electrode;
• engaging the periphery of said electrode with said unsupported workpiece leg portion and biasing said electrode as aforesaid toward said workpiece supporting electrode means;
• heating both said workpiece in that region thereof between the pressure applying, rotatable electrode and the workpiece supporting electrode means and that portion of the rotatable electrode adjacent the workpiece so that the electrode will not chill the workpiece by connecting the workpiece across an electrical power source through the pressure applying electrode and the workpiece supporting electrode means;
• so regulating the current density through the workpiece and the force exerted on it by the pressure applying electrode as to maintain the temperature of said workpiece below its melting point but sufficiently high to produce in the heated region of the workpiece between the pressure applying electrode and the workpiece supporting electrode means a localized zone in which the workpiece is in a plastic and flowable condition;
• and effecting a continuous translation of the workpiece relative to the pressure applying, rotatable electrode to thereby cause the zone in which the plastic condition exists to proceed in continuous fashion along the workpiece so that the pressure applying electrode will bend the unsupported workpiece leg portion into contact with one of said tooling means with the metal in the heated region of the workpiece flowing into contact with said one tooling means to provide a controlled contour on the inside of said bend.

The method of producing a component having a cap and a stem from a barstock type workpiece of metallic material with apparatus which includes an electrode means for supporting the workpiece, a rotatable, pressure applying electrode of a refractory metal or a refractory alloy adapted to engage the workpiece on the side thereof opposite the workpiece supporting electrode means, and means by which said rotatable electrode can be so biased toward said workpiece supporting electrode means as to exert a pressure of a predetermined magnitude on said workpiece, said method comprising the steps of:

• effecting a lateral, solid state flow of the metal in said workpiece to form a relatively thin section stem portion having an enlarged section protruberance extending along one edge thereof and laterally spreading the metal in said enlarged section while in the solid state to produce a cap disposed at an angle to said stem, each of the aforesaid steps being carried out by:
• heating both said workpiece in that region thereof between the pressure applying, rotatable electrode and the workpiece supporting electrode means and that portion of the rotatable electrode adjacent the workpiece so that the electrode will not chill the workpiece by connecting the workpiece across an electrical power source through the pressure applying electrode and the workpiece supporting electrode means;
• so regulating the current density through the workpiece being formed and the force exerted on it by the pressure applying electrode as to maintain the temperature of said workpiece below its melting point but sufficiently high to produce in the heated region of the workpiece between the pressure applying electrode and the workpiece supporting electrode means a localized zone in which the workpiece is in a plastic and flowable condition;
• and effecting a continuous translation of the workpiece relative to the pressure applying, rotatable electrode to thereby cause the zone in which the plastic condition exists to proceed in continuous fashion along the workpiece so that the forming of said stem portion and the lateral spreading of metal to form the cap can be effected in continuous fashion as said workpiece moves relative to the pressure applying electrode in the aforesaid steps.

The method of producing a component having a cap and a stem from barstock of metallic material which comprises the steps of:

• removing metal from said barstock to form a workpiece having a relatively thin section stem portion with an enlarged section protuberance extending along one edge thereof and laterally spreading the metal in said enlarged section while in the solid state to produce a cap disposed at an angle to said stem, the last-mentioned of said steps being carried out with apparatus which includes an electrode means for supporting the workpiece, a rotatable, pressure applying electrode of a refractory metal or a refractory alloy adapted to engage the workpiece on the side thereof opposite the workpiece supporting electrode means, and means by which said rotatable electrode can be so biased toward said workpiece supporting electrode means as to exert a pressure of a predetermined magnitude on said workpiece and said step being carried out by heating both said workpiece in that region thereof between the pressure applying, rotatable electrode and the workpiece supporting electrode means and that portion of the rotatable electrode adjacent the workpiece so that the electrode will not chill the workpiece by connecting the workpiece across an electrical power source through the pressure applying electrode and the workpiece supporting electrode means;
• so regulating the current density through the workpiece being formed and the force exerted on it by the pressure applying electrode as to maintain the temperature of said workpiece below its melting point but sufficiently high to produce in the heated region of the workpiece between the pressure applying electrode and the workpiece supporting electrode means a localized zone in which the workpiece is in a plastic and flowable condition;
• and effecting a continuous translation of the workpiece relative to the pressure applying, rotatable electrode to thereby cause the zone in which the plastic condition exists to proceed in continuous fashion along the workpiece so that the spreading of the metal in said enlarged section can be effected in continuous fashion as said workpiece moves relative to the pressure applying electrode.

A method for the solid state forming of a metallic workpiece into a component of selected configuration with apparatus which includes an electrode means for supporting the workpiece, a rotatable, pressure applying electrode of a refractory metal or a refractory alloy having therein a cavity of the configuration which is to be imparted to the workpiece and adapted to engage the workpiece on the side thereof opposite the workpiece supporting electrode means, and means by which said rotatable electrode can be so biased toward said workpiece supporting electrode means as to exert a pressure of a predetermined magnitude on said workpiece, said method comprising the steps of:

• heating both said workpiece in that region thereof between the pressure applying, rotatable electrode and the workpiece supporting electrode means and that portion of the rotatable electrode adjacent the workpiece so that the electrode will not chill the workpiece by connecting the workpiece across an electrical power source through the pressure applying electrode and the workpiece supporting electrode means;
• so regulating the current density through the workpiece being formed and the force exerted on it by the pressure applying electrode as to maintain the temperature of said workpiece below its melting point but sufficiently high to produce in the heated region of the workpiece between the pressure applying electrode and the workpiece supporting electrode means a localized zone in which the workpiece is in a plastic and flowable condition so that workpiece metal will flow into the cavity in the pressure applying electrode to impart the desired configuration to the workpiece;
• and effecting a translation of the workpiece relative to the electrode to thereby cause the zone in which the workpiece is plastic to progress along said workpiece so that successive increments of said workpiece are formed to shape as said workpiece is moved relative to the electrode.

A multi-stage method of forming a component from a metallic workpiece in apparatus which comprises, in each of plural stages, an electrode means for supporting the workpiece, a rotatable, pressure applying electrode of a refractory metal or a refractory alloy adapted to engage the workpiece on the side thereof opposite the workpiece supporting electrode means, and means by which said rotatable electrode can be so biased toward said workpiece supporting electrode means as to exert a pressure of a predetermined magnitude on said workpiece, said method comprising the steps of, in each of said stages:

• heating both said workpiece in that region thereof between the pressure applying, rotatable electrode and the workpiece supporting electrode means and that portion of the rotatable electrode adjacent the workpiece so that the electrode will not chill the workpiece by connecting the workpiece across an electrical power source through the pressure applying electrode and the workpiece supporting electrode means;
• so regulating the current density through the workpiece being formed and the force exerted on it by the pressure applying electrode as to maintain the temperature of said workpiece below its melting point but sufficiently high to produce in the heated region of the workpiece between the pressure applying electrode and the workpiece supporting electrode means a localized zone in which the workpiece is in a plastic and flowable condition;
• and effecting a continuous translation of the workpiece relative to the pressure applying, rotatable electrode to thereby cause the zone in which the plastic condition exists to proceed in continuous fashion along the workpiece so that the forming of the workpiece can be effected in continuous fashion as said workpiece moves relative to the pressure applying electrode.

A method for the solid state forming of a metallic workpiece with apparatus which includes three rotatable electrodes of a refractory metal or a refractory alloy mounted opposite each other for rotation about intersecting axes with an opening therebetween through which a workpiece can be fed and means for biasing at least one of said electrodes toward said opening to exert a pressure of predetermined magnitude on said workpiece, said method comprising the steps of:

• heating both said workpiece in that region thereof between the rotatable electrodes and those portions of the electrodes adjacent the workpiece so that said electrodes will not chill the workpiece by connecting the workpiece across a different one of the phases of a three-phase power supply through each of the three electrode pairs afforded by said three electrodes;
• so regulating the current density through the workpiece and the pressure exerted on it by the rotatable electrodes as to maintain the temperature of the workpiece below its melting point but sufficiently high to produce in the heated region of the workpiece between the electrodes a localized zone in which the workpiece is in a plastic and flowable condition;
• and effecting a continuous translation of the workpiece relative to the rotatable electrodes to thereby cause the zone in which the plastic condition exists to proceed in continuous fashion along the workpiece so that the forming of the workpiece can be effected in continuous fashion as said workpiece moves relative to said rotatable electrodes.

A method for the solid state forming of a metallic workpiece into a component of selected configuration with apparatus which includes a workpiece supporting electrode means for supporting the workpiece, a rotatable, pressure applying electrode means of a refractory metallic material having a melting point above the range of iron, cobalt, and nickel adapted to engage the workpiece on the side thereof opposite the workpiece supporting electrode means, and means by which said rotatable electrode means can be so biased toward said workpiece supporting electrode means as to exert a pressure of a predetermined magnitude on said workpiece, said method comprising the steps of:

• heating both said workpiece in that region thereof between the refractory, pressure applying, rotatable electrode means and the workpiece supporting electrode means and that portion of the rotatable electrode means adjacent the workpiece so that the electrode means will not chill the workpiece by connecting the workpiece across an electrical power source through the pressure applying electrode means and the workpiece supporting electrode means to thereby effect resistance heating of said electrode means and said workpiece;
• so regulating the current density through the workpiece being formed and the force exerted on it by the pressure applying electrode means as to maintain the temperature of said workpiece below its melting point but sufficiently high to produce in the heated region of the workpiece between the pressure applying electrode means and the workpiece supporting electrode means a localized zone in which the workpiece is in a plastic and flowable condition;
• and effecting a continuous translation of the workpiece relative to the pressure applying, rotatable electrode means to thereby cause the zone in which the plastic condition exists to proceed in continuous fashion along the workpiece so that the forming of the workpiece can be effected in continuous fashion as said workpiece moves relative to the pressure applying electrode means.