Solder alloy, use of the solder alloy and method for processing, particularly repairing, workpieces, particularly gas turbine components

Abstract

A solder alloy and a multi-component soldering system, to the use of the same, and to a method for repairing gas turbine components are described herein. The solder alloy based on nickel includes the following elements: nickel (Ni), chromium (Cr), cobalt (Co), molybdenum (Mo), aluminum (Al), tantalum (Ta), niobium (Nb), yttrium (Y), hafnium (Hf), palladium (Pd), boron (B) and silicon (Si). The multi-component soldering system includes the solder alloy and additionally at least one additive material. The additive materials include the following elements: nickel (Ni), chromium (Cr), cobalt (Co), molybdenum (Mo), aluminum (Al), tantalum (Ta), titanium (Ti), rhenium (Re), iron (Fe), niobium (Nb), yttrium (Y), hafnium (Hf), palladium (Pd), carbon (C), zirconium (Zr), boron (B) and silicon (Si). A specific mixing of solder alloy and additive materials produces a multi-component soldering system that may be specifically adapted to the material of the component to be repaired, the mixture ratio of solder alloy and additive materials being freely selectable. The repair method is based on high-temperature diffusion soldering using the solder alloy hereof or the multi-component soldering system hereof.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a solder alloy as well as a multi-component soldering system. Furthermore, the present invention relates to the use of a solder alloy and of a multi-component soldering system as well as to a method for processing, e.g., repairing, workpieces, e.g., of gas turbine components. BACKGROUND INFORMATION [0002] Gas turbines, as for example aircraft engines or stationary gas turbines, in operation are subject to high mechanical and thermal stress. Thus, during the operation of an aircraft engine, blades, e.g., turbine blades, may be damaged by alternating thermal stress and material removal. This results in thermal fatigue cracks and eroded surfaces, which must be completely and reliable repaired when servicing or repairing the aircraft engine. For this purpose, conventionally, soldering methods are used in addition to welding methods. [0003] In this connection, conventionally, soldering methods and solder materials are uses as...

AI Technical Summary

Benefits of technology

[0005] According to an example embodiment of the present invention, the solder alloy is a nickel-based alloy and includes at least the following elements: chromium (Cr), cobalt (Co), molybdenum (Mo) and nickel (Ni). The molybdenum (Mo) replaces the tungsten (W) using in conventional solder alloy. By mixed crystal hardening, molybdenum (Mo) increases the strength of the γ-nickel matrix, without, however, disadvantageously increasing the melting point of the solder alloy to the same extent as tungsten (W).

[0016] Palladium (Pd) lowers the melting point of the solder alloy and increases the strength of the γ-nickel matrix by mixed crystal hardening. Furthermore, it may be provided that palladium (Pd) improves the wetting behavior and the fluidity of the molten solder alloy or of the molten multi-component soldering system.

[0027] The solder alloy may additionally include yttrium (Y) in a proportion of 0.1 to 1 wt. % and hafnium (Hf) in a proportion of 1 to 5 wt. %. Like Palladium (Pd), hafnium (Hf) may improve the wetting behavior and the fluidity of the molten solder alloy or of the molten multi-component soldering system and increases at the same time the oxidation-resistance of the soldered regions. In order to keep the portion of hafnium-containing hard phases low, which may embrittle the solder structure, the hafnium portion is limited to 5 wt. %.

[0028] Like palladium (Pd) and boron (B), yttrium (Y) may lower the melting point or the melting range of the solder alloy such that soldering temperatures may be set specifically in the range of 1200° C. to 1260° C. by the combination of elements Pd—B—Y.

Problems solved by technology

Gas turbines, as for example aircraft engines or stationary gas turbines, in operation are subject to high mechanical and thermal stress.

Thus, during the operation of an aircraft engine, blades, e.g., turbine blades, may be damaged by alternating thermal stress and material removal.

This results in thermal fatigue cracks and eroded surfaces, which must be completely and reliable repaired when servicing or repairing the aircraft engine.