Home      Exposition      To Register      ASM Homepage
Back to "Session 6: Cold Spray 6: Applications" Search
  Back to "Cold Spray" Search  Back to Main Search

Tuesday, May 16, 2006 - 10:50 AM
CSP2.2

Depositing Titanium Alloy Additive Features to Forgings and Extrusions Using the Cold Spray Process

R. E. Blose, Ktech Corporation, Albuquerque, NM; B. H. Walker, R. M. Walker, Keystone Synergistic Enterprises, Inc., Port St. Lucie, FL; S. H. Froes, University of Idaho, Moscow, ID

Development of new low-cost methods for spray forming Titanium alloys is critical for many industries.  Direct fabrication technologies would have an impact on many industries because of the potential for quick manufacture of parts or additive features with minimal waste.  For example in the aerospace industry the buy to fly ratios can vary from 1.5:1 for turbine blades to over 22:1 for structural members.  The buy to fly ratio is the mass of material that is require to machine a part compared to the mass of material in the finished part.  For compressor and ring sections the ratio is approximately 12:1.  For this family of parts an analysis by Pratt & Whitney indicated that the buy to fly ratio could be reduced by 41% to 7:1 if cold spray could be implemented to deposit isogrids, structural ribbing, bosses, and flanges reducing the material, machining, and post processing required for the final part.  This paper examines the deposition of two Ti-6Al-4V powders one produced by plasma atomization and the other by the Armstrong process.  We will describe the techniques developed to reduce the porosity of the as sprayed Ti-6Al-4V coatings and the post processing techniques used to improve the properties of the coating.  Data will be presented describing bond strength, tensile properties, and toughness of the post-processed coatings comparing both types of powders. 

 


Summary: Development of new low-cost methods for spray forming Titanium alloys is critical for many industries. Direct fabrication technologies would have an impact on many industries because of the potential for quick manufacture of parts or additive features with minimal waste. For example in the aerospace industry the buy to fly ratios can vary from 1.5:1 for turbine blades to over 22:1 for structural members. The buy to fly ratio is the mass of material that is require to machine a part compared to the mass of material in the finished part. For compressor and ring sections the ratio is approximately 12:1. For this family of parts an analysis by Pratt & Whitney [1] indicated that the buy to fly ratio could be reduced by 41% to 7:1 if cold spray could be implemented to deposit isogrids, structural ribbing, bosses, and flanges reducing the material, machining, and post processing required for the final part. This paper summarizes the results of experiments conducted in Phase I of a National Science Foundation grant to spray form Titanium alloy using the cold spray process. This paper further describes the studies performed to date in Phase II and the techniques used to decrease the porosity of the as sprayed coating from 18% to between 2% and 7%. Also described is the post processing methods employed to establish a metallurgical bond between the Ti-6Al-4V coating and substrate which is foundational to depositing additive net shaped features to aerospace components.