Process modeling for solidification microstructure and transient thermal stresses in laser aided DMD process

Author

Suhash Ghosh

Abstract

"Despite enormous progress in Laser Aided Direct Material Deposition (DMD) process adverse effects of process parameters on variety of properties and microstructure have been reported. De-bonding at substrate-deposition interface and cracking in deposited layers are a few that occur due to excessive stress build-up. Very high heating and cooling rates are inherent to this process. Consequently, the effects of solid state phase transformations cannot be neglected. A complete model that provides a quantitative relationship between process parameters, phase transformation kinetics, solidification parameters, thermal stresses and microstructure is highly desirable. This research deals with four key aspects of laser aided DMD. First, effect of solid state phase transformation on thermal stresses. Second, influence of high cooling rates on solidification microstructure at the scale of primary and secondary dendrite arm spacing. Third, effect of deposition patterns on both thermal stresses and solidification microstructure. And fourth, development of a fully coupled temperature-stress/strain field model"--Abstract, page iii.

Advisor(s)

Choi, Joohyun

Committee Member(s)

Kim, Seungjin
Story, J. Greg
Tsai, Hai-Lung
Chandrashekhara, K.

Department(s)

Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering

Sponsor(s)

University of Missouri--Rolla. Department of Mechanical and Aerospace Engineering

Publisher

University of Missouri--Rolla

Publication Date

Spring 2006

Pagination

xv, 146 pages

Note about bibliography

Includes bibliographical references (pages 139-145).

Rights

© 2006 Suhash Ghosh, All rights reserved.

Document Type

Dissertation - Citation

File Type

text

Language

English

Subject Headings

Lasers -- Industrial applicationsMicrostructureResidual stressesThermal stresses

Thesis Number

T 9001

Print OCLC #

123352084

Recommended Citation

Ghosh, Suhash, "Process modeling for solidification microstructure and transient thermal stresses in laser aided DMD process" (2006). Doctoral Dissertations. 1690.
https://scholarsmine.mst.edu/doctoral_dissertations/1690