Masters Theses

Keywords and Phrases

Additive Manufacturing; Direct Metal Deposition; Micro-hardness; Peltier effect; Powder feed; Thermo-electric cooling

Abstract

”Nickel hard-surfacing alloys are replacing hard Chromium coatings due to their excellent wear and corrosion-resistant properties. In laser cladding of these alloys, however, these properties can vary across the height of the deposit due to an accumulation of excess heat generated in the deposit during the process. This may result in uneven wear of the clad parts which can be detrimental for practical purposes. The research objective is to develop an in-situ cooling system that works in line with the laser deposition system to extract the excess heat buildup and reduce the variation in the hardness of the Ni-based clad alloy deposit across its height.

This thesis discusses a new network system with two-way communication between the developed cooling system and the laser system. A thermo-electric cooling system was decided on to act as the optimal cooling system. The two systems work in-hand with each other to automate the process of extracting heat from the deposits. The study focusses on developing the cooling system, integrating the system into the existing laser system, laser deposition with the new integrated system, sample preparation and mechanical testing. Comparative micro-hardness tests have been performed on deposits made with the new system and without. The results indicate a significant reduction in the variation of the microhardness across the deposit along with an enhancement in the mean hardness value of the clad material”--Abstract, page iii.

Advisor(s)

Liou, Frank W.

Committee Member(s)

Pan, Heng
Chen, Lianyi

Department(s)

Mechanical and Aerospace Engineering

Degree Name

M.S. in Manufacturing Engineering

Comments

This research project was supported by the National Science Foundation Grant CMMI-1547042.

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2017

Pagination

ix, 48 pages

Note about bibliography

Includes bibliographic references (pages 44-47).

Rights

© 2017 Raghu Ram Kolla, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 12025

Electronic OCLC #

1313117322

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