Mechanical & Materials Engineering, Department of

 

Date of this Version

12-2012

Comments

A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Mechanical Engineering, Under the Supervision of Professor Robert Williams. Lincoln, Nebraska: December, 2012

Copyright (c) 2012 Matthew S. Kalus

Abstract

Sustainability is more important in today's culture due to the increasing demand for a more eco-friendly society. Concentrations in minimizing and reducing environmental impacts, energy and natural resources have been forthcoming in industry. The tool, mold and die industries are the most well known industries that machine harder materials using mills and WEDM. The objective of this thesis was to compare the sustainability differences in both of these machines utilizing the accepted standards for evaluating the manufacturing process performance for sustainability. These standards include the evaluation of the process parameters, raw materials, power, tools and fluids which all contribute to different effects in the environment, machining performance and operator safety. An experiment was conducted on both machines to study the power differences by altering the machines' cutting parameters on a D2 tool steel workpiece. Current, surface roughness, metal removal rates and tool wear were documented. Increases in power and tool wear can be controlled by varying process parameters such as using cutting fluids and changing the metal removal rate. A higher metal removal rate increased the amount of power used but did not improve surface roughness. Milling and WEDM operations exhibited a similar specific energy trend which is considered another way of comparing both machines. Surface roughness was shown to be better at higher specific energies for WEDM. In milling, lower surface roughness numbers were seen in a broad range of specific energies. Overall, a correlation between the metal removal rate, power and surface roughness affected sustainability.

Advisor: Robert Williams