Doctoral Dissertations

Keywords and Phrases

Cryogenic Cooling; Fast Fourier Transforms; Inconel-718; Minimum Quantity Lubrication; Tool Wear; Up and Down Milling

Abstract

“Inconel-718 superalloy is used extensively in aerospace and nuclear industries due to its excellent properties such as: high strength-to-weight ratio, ability to retain its properties at high temperature, high corrosion and creep resistance. However, Inconel-718 is characterized as a “difficult-to-cut metal”, because it poses severe problems during machining such as: high temperature at the cutting zone due to low thermal conductivity, hardening tendency at elevated temperature, high cutting forces, rapid tool wear and high chemical affinity with many cutting tools. Appropriate cooling strategies, milling methods, tool coatings and cutting speeds play important roles in addressing these problems. This research presents the results of the effects of end-milling methods (Up and down-milling), cooling strategies (Conventional emulsion cooling, Minimum Quantity Lubrication (MQL), Liquid Nitrogen (LN2) and (MQL+LN2)) and tool coatings (Uncoated, AlTiN and GMS2) on cutting forces, cutter tooth frequency, tool wear, chip morphology and surface roughness in high-speed end-milling of Inconel-718 to improve its machinability and reduce cost. Firstly, a comparative investigation of milling methods and cooling strategies using uncoated tools was conducted and analyzed to find better milling method and three best cooling strategies to perform further experiments using coated tools. Results show that down-milling improves machinability. Then, the performance of three tool coatings and three best cooling strategies (MQL, LN2 and (MQL+LN2)), determined from first set of experiments was analyzed. Finally, the best cooling strategy and tool coating were determined for machining Inconel-718 at given parameters. Results show that MQL, an environmentally friendly cooling strategy, improves machinability and can successfully replace conventional emulsion cooling”--Abstract, page iv.

Advisor(s)

Okafor, A. Chukwujekwu (Anthony Chukwujekwu)

Committee Member(s)

Chandrashekhara, K.<
Dharani, Lokeswarappa R.
Chen, Lianyi
Samaranayake, V. A.

Department(s)

Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering

Comments

The financial support from the Intelligent System Centre (ISC) of the Missouri University of Science and Technology is greatly acknowledged.

Research Center/Lab(s)

Intelligent Systems Center

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2018

Journal article titles appearing in thesis/dissertation

  • Effects of up-milling and down-milling methods, and cooling strategies on cutting forces and tooth frequency in high speed end-milling of Inconel 718 using uncoated solid carbide end-mills
  • Effects of cooling strategies and tool coatings on cutting forces and tooth frequency in high speed down-milling of Inconel-718 using helical bull-nose solid carbide end-mills
  • Effects of up and down-milling, and cooling strategies on tool wear, chip morphology and surface roughness in high speed end-milling of Inconel-718
  • Effects of tool coatings and cooling strategies on tool wear, chip morphology and surface roughness in high speed down-milling of Inconel 718

Pagination

xx, 198 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2018 Paras Mohan Jasra, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 12085

Additional Files
T12085.pdf (87 kB)
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