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Impact of Nozzle Condition on Powder Catchment Efficiency for Coaxial Powder Direct Energy Deposition...

by Lauren E Heinrich, Joseph Fletcher, Thomas A Feldhausen, Thomas Kurfess, Christopher Saldana
Publication Type
Conference Paper
Book Title
Proceedings of the 33rd Annual International, SOLID FREEFORM FABRICATION SYMPOSIUM 2022, – An Additive Manufacturing Conference –
Publication Date
Page Numbers
1091 to 1099
Publisher Location
Austin, Texas, United States of America
Conference Name
Annual International in Person Solid Freeform Fabrication Symposium
Conference Location
Austin, Texas, United States of America
Conference Sponsor
The University of Texas at Austin
Conference Date

Blown powder directed energy deposition is well-designed for fine resolution additive manufacturing processing. Coaxial powder deposition heads use an outer layer of shielding gas directed by an outer nozzle to prevent oxidation occurring during the powder melting process. Powder blown feedstock catchment efficiency can be as low as 50-80% whereas wire deposition systems are closer to 98% efficient. The present study evaluates the impact of directed energy deposition nozzle condition on catchment efficiency. Changes in the overall outer shielding gas nozzle length has been found to increase material usage efficiency by 10% through convergence of the powder flow. The results of this experiment show that for coaxial powder deposition head design, if the standoff distance can safely be decreased, powder catchment efficiency can be increased as the outer shielding gas nozzle is increased in length, or the standoff distance is decreased.