Effects of milling methods, cooling strategies and end-mill coatings on machinability in high speed end-milling of Inconel- 718 using carbide end-mills

<p>“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.</p>

Name thesis:degree_name

Ph. D. in Mechanical Engineering

Grantor

Missouri University of Science and Technology

Author dc:creator

• Jasra, Paras Mohan

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

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/3130

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-4135