Masters Theses

Keywords and Phrases

Cryogenic Machining; Cutting Force Components; High-Speed end-milling; Inconel 718; Minimum Quantity Lubrication


“This thesis presents the results of the experimental investigation of the effects of machining parameters (spindle speed and feedrate) and cooling strategies [Minimum Quantity Lubrication (MQL), Cryogenic Liquid Nitrogen (LN2), and combined (MQL+LN2)] on cutting force components, cutting temperature, tool wear and surface roughness during high-speed slot end-milling of Inconel 718 alloy. In addition, a comparative evaluation of the three cooling strategies was conducted for cutting force components, surface roughness and residual stresses. All end-milling experiments were conducted on a Cincinnati Milacron Vertical Machining center (VMC), using a 0.5 inch (12.7 mm) diameter, 0.03 inch (0.762 mm) corner radius four-flute uncoated carbide end-mill. A one-third fractional factorial design of experiments was constructed (nine experimental runs) and used in analyzing all experimental results. Cutting force components were acquired using a Kistler type 9272 4-component dynamometer, which was connected to an amplifier and a junction box. Cutting temperature was measured using a 0.125 inch (3.175 mm) diameter ungrounded k-type thermocouple, while tool wear was investigated indirectly by analyzing the maximum cutting force components of the last two passes (19 and 20). Surface roughness and residual stresses were measured using a profilometer and X-ray diffraction respectively. The results showed that high spindle speed (750 rpm) and medium feed rate (2 ipm) gave the lowest cutting force components, while low spindle speed (250 rpm) gave the lowest cutting temperature and tool wear. Furthermore, a low spindle speed (250 rpm) and feed rate (1 ipm) gave the least surface roughness, while MQL cooling strategy induced the highest compressive stresses”--Abstract, page iv.


Okafor, A. Chukwujekwu (Anthony Chukwujekwu)

Committee Member(s)

Chandrashekhara, K.
Sarangapani, Jagannathan, 1965-


Mechanical and Aerospace Engineering

Degree Name

M.S. in Mechanical Engineering


The financial support from the National Science Foundation (NSF) under grant No. CMMI800871 and the Intelligent Systems Center (ISC) of the Missouri University of Science and technology are gratefully acknowledged.

Research Center/Lab(s)

Intelligent Systems Center


Missouri University of Science and Technology

Publication Date

Fall 2014

Journal article titles appearing in thesis/dissertation

  • Investigating the effects of machining parameters and cooling strategies on cutting force, tool wear and cutting temperature in high-speed slot end-milling of Inconel 718
  • Comparative evaluation of cooling strategies and the effects of machining parameters on surface roughness and residual stresses in high-speed end-milling of Inconel 718


xiv, 167 pages

Note about bibliography

Includes bibliographic references.


© 2014 Chukwujekwu Ikwy Nnadi, All rights reserved.

Document Type

Thesis - Open Access

File Type




Thesis Number

T 12040

Electronic OCLC #