Apparatus and method for direct writing of single crystal super alloys and metals

Abstract

Apparatus and methods for direct writing of single crystal super alloys and metals are provided. In one method, a substrate is heated to a pretermined temperature below its melting point, and a laser is used to form a melt pool on a surface of a substrate. The substrate is positioned on a base plate, and the laser and the base plate are movable relative to each other, with the laser being used for direct metal deposition and the substrate is heated to a temperature below its melting point. A superalloy powder is introduced to the melt pool, and the temperature of the melt pool is controlled to maintain a predetermined thermal gradient on a solid and liquid interface of the melt pool so as to form a single crystal deposit on the substrate.

Description

PRIORITY INFORMATION[0001]The present application claims priority to U.S. Provisional Patent Application Ser. No. 62 / 041,884 titled “Apparatus and Method for Direct Writing of Single Crystal Super Alloys and Metals” of Mazumder, et al. filed on Aug. 26, 2014, which is incorporated by reference herein.FIELD OF THE INVENTION[0002]The present disclosure relates to an apparatus and method for direct writing of single crystal super alloys and metals.BACKGROUND OF THE INVENTION[0003]The turbine section of a gas turbine engine is located downstream of a combustor section and contains a rotor shaft and one or more turbine stages, each having a turbine disk (rotor) mounted or otherwise carried by the shaft and turbine blades mounted to and radially extending from the periphery of the disk. Components within the combustor and turbine sections are often formed of superalloy materials to provide acceptable mechanical properties while at elevated temperatures resulting from the hot combustion ga...

AI Technical Summary

Benefits of technology

The invention provides methods and apparatus for direct writing of single crystal super alloys and metals. The method involves heating the substrate and using a laser to form a melt pool on the substrate. Superalloy powder is then introduced into the melt pool to form a single crystal deposit. The apparatus includes a laser, a base plate for holding the substrate, a DMD head for supplying the superalloy powder, an induction heating source for heating the substrate, and a controller for controlling the power output of the laser to maintain the predetermined temperature. The invention allows for the production of high-quality single crystal materials with improved properties.

Problems solved by technology

However, single crystal casting is a slow and expensive process.

Due to high melting temperature of the Nickel superalloy, often expensive ceramic molds are required.

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