Honors Theses

Date of Award

Summer 4-27-2022

Document Type

Undergraduate Thesis

Department

Mechanical Engineering

First Advisor

Shan Jiang

Second Advisor

Samrat Choudhury

Third Advisor

Yewei Han

Relational Format

metadata

Abstract

Using molecular dynamics (MD) simulations, the laser sintering additive manufacturing process is investigated through the observation of γ-TiAl nanoparticles. This process is conducted using both uni-directional chain and stacking configurations. By mimicking the heating process and varying laser sintering parameters such as heating rater, sintering temperature, and particle orientation, the fusion behavior and resulting products are analyzed for both chain and stacking NP patterns. In of single chain cases, it is noticed that slower heating rates and higher melting temperatures yield larger neck growth between each individual particle and thus produce a more stable product. This leads to stronger mechanical properties in subsequent tensile testing of the NP chain. In stacking configurations, it can be noticed that faster heating rates in stacking sequences yield for higher fusion temperatures which is contradictory to most past studies of the same nature using single chain patterns. Additionally, it is concluded that the closed pack (“Type C”) stacking sequence also yields a higher melting temperature than the aligned pattern (“Type A”) due to the increased number of neck connections and thus increased stability in the “Type C” NP stacks. Lastly in stacking patterns, it can be realized that varying particle orientation, while making a slight impact on in NP interaction in the melting process, yields no consistent trend, thus aligning with the random nature of particle orientation in real physical cases of NP laser sintering.

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