Title: Heat Treatment of AA2024 Powders for Enhanced Solid State Structural Repairs Via Cold Spray Deposition
Authors: William A. Story, Tian Liu, and Luke N. Brewer
Abstract: This presentation will describe new results on the heat treatment of AA2024 feedstock powder for cold spray deposition. Cold spray deposition is being developed as a means for repairing corrosion damage in high strength aluminum aircraft components. The microstructure of gas atomized powders is not optimized for spray characteristics or mechanical properties. We have applied a new heat treatment approach to solutionize these powders, thus removing the intermetallic network. Powders were solutionized for 75 minutes at 498°C in a rotary furnace and then quenched. For comparison, other powders were intentionally aged at 150°C and 225°C for 20 hours. All of these powders were sprayed onto AA2024 substrates using the VRC Metal Systems generation III cold spray system with helium as the spray gas. The mass deposition efficiency improved from 46% to 75% for the solutionized powders. The 150°C/20hour sample showed a reduction in deposition efficiency to 38%, while the 225°C/20hour sample increased to 61%. Microscopy of the particles showed that the solution treatment removed the majority of the S phase intermetallic network, while the overaging treatments did not. S’ precipitates were not observed in coatings produced with feedstock powder but were present after natural aging for coatings produced with solutionized powders.
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Conference: SAMPE 2019 - Charlotte, NC
Publication Date: 2019/05/20
Price: FREEGet This Paper