US 4,902,355 AGranted

Method of and a spray for manufacturing a titanium alloy

AssigneeBohler Gesellschaft m.b.H.

InventorsRobert I. Jaffee, Herbert H. Puschnik, Johann Fladischer, Johann Mayerhoffer, Heimo Jager

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Abstract

A method of manufacturing a titanium alloy, wherein a melted and possibly preformed part is annealed to set the starting grain structure, wherewith a first grain structure transformation is accomplished by a first cooling step, whereafter high dislocation densities are produced in the course of a hot forming step, whereupon heat treatment involving a recrystallization is carried out, wherewith in the course of a subsequent cooling a predominantly or substantially martensitic breakdown is achieved, wherewith a grain structure transformation is carried out in a subsequent annealing process, and wherewith in the course of a subsequent chilling a fine grain structure is set. At least the first cooling step is accomplished by spraying the preformed part with water and/or water-air mixtures. A spray device may be used for carrying out the method.

Claims20

Dependent claims

A method of manufacturing .alpha.+.beta. Titanium alloys with a content of about six percent by weight of Aluminum, about four percent by weight of Vanadium, and impurities associated with the process, comprising:

annealing a molten workpiece of an .alpha.+.beta. Titanium alloy having a content of about six percent by weight of Aluminum and about four percent by weight of Vanadium, at 1040.degree.-1060.degree. C. to set the .beta.-phase and produce a preform grain structure with a lamellar matrix of .alpha.+.beta.-phase;
converting the grain structure to one of a fine lamellar .alpha.+.beta.-phase and a very fine .alpha.+.beta.-phase during a first cooling step by spraying the workpiece with streams of one of water and an water-air mixture;
hot forming the workpiece with a degree of deformation of at least 60% at a temperature of about 850.degree.-1000.degree. C. to produce a high dislocation density;
controlling recrystallization of grain structure setting by subjecting the workpiece to a heat treatment at about 950.degree. C. to establish a .beta.-matrix with a finely divided globulitic .alpha.-phase;
subjecting the workpiece to a subsequent cooling step to achieve substantial martensitic breakdown of the .beta.-matrix;
and
subjecting the workpiece to a subsequent annealing step to convert the martensitic matrix to a lamellar .alpha.+.beta.-phase.

4 more elements

annealing a molten workpiece of an .alpha.+.beta. Titanium alloy having a content about six percent by weight of Aluminum and about four percent by weight of Vanadium, at 1040.degree.-1060.degree. C. to set the .beta.-phase and produce a preform grain structure with a lamellar matrix of .alpha.+.beta.-phase;
converting the grain structure to one of a fine lamellar .alpha.+.beta.-phase and a very fine .alpha.+.beta.-phase during a first cooling step by spraying the workpiece with streams of one of water and a water-air mixture;
hot forming the workpiece with a degree of deformation of at least 60% at a temperature between about 30.degree.-50.degree. C. below the transition temperature of the alloy to produce a high dislocation density;
subjecting the workpiece to a second cooling step by spraying the workpiece with streams of one of water and a water-air mixture;
controlling recrystallization of grain structure setting by subjecting the workpiece to a heat treatment at about 950.degree. C. to establish a .beta.-matrix with a finely divided globulitic .alpha.-phase;
subjecting the workpiece to a subsequent cooling step to achieve substantial martensitic breakdown of the .beta.-matrix by spraying the workpiece with streams of one of a water-air mixture;
and
subjecting the workpiece to a subsequent annealing step to convert the martensitic matrix to a lamellar .alpha.+.beta.-phase.

5 more elements

Dependencies are inferred from the claim text.