Masters Theses

Keywords and Phrases

Additive Manufacturing; Direct Metal Deposition; Disk feeder; Performance metric; Powder feeder


"In blown powder Direct Metal Deposition (DMD) process, parts are built by adding metal powder on the melt pool created by the laser system. At low feed rates powder feeder systems have perturbations. The study focused on relationship between the perturbation frequencies by inherent powder feeder designs and its impact on deposition quality. Performance metric determine the relation between perturbations in the powder flow and quality of the deposit. To determine performance metric, various powder feeder designs were analyzed. Perturbation frequencies were introduced to the disk feeder design. The quality of the deposit was determined by the surface roughness of the deposit. A laser displacement sensor was used to measure the surface roughness of the deposits. Experiments were carried out to determine the significance between measured surface roughness values of the deposits over theoretically calculated performance metric values. Validation tests were done to compare the data fit. The wheel feeder and newly developed disk feeder were compared for deposit quality. The results showed better performance metric for the disk feeder system under the same process parameters. Based on this metric, a feeder system can be chosen in the future to produce Functionally Graded Materials (FGM)"--Abstract, page iii.


Liou, Frank W.

Committee Member(s)

Newkirk, Joseph William
Pan, Heng


Materials Science and Engineering

Degree Name

M.S. in Manufacturing Engineering


Missouri University of Science and Technology. Department of Manufacturing Engineering


Missouri University of Science and Technology

Publication Date

Fall 2015


ix, 35 pages

Note about bibliography

Includes bibliographical references (pages 33-34).


© 2015 Venkata Sivaram Bitragunta, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Manufacturing processes -- Research
Pulsed laser deposition
Metal powders

Thesis Number

T 10781

Electronic OCLC #


Included in

Manufacturing Commons