Abstract: The invention relates to a joint prosthesis having a shaft made from a titanium alloy, in which at least the shaft is investment cast and has a body-centered cubic crystal structure. A titanium alloy having this crystal structure (known as ?-titanium alloy) has an advantageously low modulus of elasticity which is well matched to the physiological demands of joint prostheses. Furthermore, implementation as a shaped casting allows a complex shape to be achieved. It is particularly embodied as a femoral prosthesis for an artificial hip joint, which has an elongate shaft with grooves and sawtooth-like projections for bone anchoring.

Abstract: A process for producing a medical implant from a titanium alloy, by investment-casting a ?-titanium alloy in a casting mold which corresponds to the implant that is to be produced, hot isostatic pressing, solution annealing, and then quenching. The corresponding medical implant is produced from the titanium alloy using the investment casting process, thus allowing economical production of objects from ?-titanium alloys. The ?-titanium alloy and has a mean grain size of at least 0.3 mm. It is possible to combine the advantageous properties of ?-titanium alloys, in particular their excellent mechanical properties, with the advantages of producing objects by the precision casting process, thus enabling even implants of complex shapes, such as femur parts of hip joint prostheses, which have heretofore been impossible (economically) to produce by conventional forging processes, to be produced from a ?-titanium alloy.

Abstract: The invention relates to a process for producing a medical implant from a titanium alloy, by investment-casting the titanium alloy in a casting mold which corresponds to the implant that is to be produced. The invention provides for using a ?-titanium alloy, hot isostatic pressing, solution annealing, and then quenching. The invention also covers a corresponding medical implant which has been produced from a titanium alloy using the investment casting process. The titanium alloy is a ?-titanium alloy and has a mean grain size of at least 0.3 mm. The invention allows economical production of objects from ?-titanium alloys using the investment casting process. The invention thereby makes it possible to combine the advantageous properties of ?-titanium alloys, in particular their excellent mechanical properties, with the advantages of producing objects by the precision casting process.

Abstract: The invention relates to a joint prosthesis having a shaft made from a titanium alloy; according to the invention, it is provided that at least the shaft (10) is investment-cast and has a body-centered cubic crystal structure. A titanium alloy having this crystal structure (known as ?-titanium alloy) has an advantageously low modulus of elasticity which is well matched to the physiological demands. Furthermore, implementation as a shaped casting allows a complex shape to be achieved. It is particularly expediently embodied as a femoral prosthesis (1) for an artificial hip joint, which has an elongate shaft (10) with grooves (14) and sawtooth-like projections (15) for bone anchoring.

Abstract: The invention relates to a process for casting objects from a ?-titanium alloy comprising titanium-molybdenum with a molybdenum content of from 7.5 to 25%. The invention provides for melting the alloy at a temperature of over 1770° C., investment-casting the molten alloy into a casting mold corresponding to the object to be produced, hot isostatic pressing, solution annealing and then quenching. The process according to the invention provides economic production of objects made from ?-titanium alloys using the investment-casting process. The invention thereby provides the possibility of combining the advantageous properties of ?-titanium alloys, in particular their excellent mechanical properties, such as the low modulus of elasticity, with the advantages of producing castings using the investment-casting process. The invention means that even objects of complex shapes, which it was impossible to produce (economically) by conventional forging processes can be produced from a ?-titanium alloy.