Bimetallic Tubulars via Spray Forming.

摘要

High deposition rate spray forming is a new technology which has been developed to reduce the costs and to improve the performance of a wide variety of engineering alloys. The purpose of this investigation was to demonstrate the ability to produce layered bimetallic structures via the spray forming process. Copper tubulars were used as collectors for spray deposited alloy 625. The collectors were varied in thickness and various interfacial alloys were incorporated to promote bonding between the copper and superalloy. Microstructures and bond strength were determined. In the spray deposition process, a stream of molten metal is atomized by inert gas, producing a spray of liquid droplets which are cooled by the gas and accelerated towards a substrate, where they consolidate to form a nearly fully dense deposit. The process improves on ingot metallurgy in that a rapidly solidified, grain-refined microstructure with limited segregation is produced.