Sustainability Assessment of Machining Processes

Abstract

There is an increased interest in sustainability assessment of manufacturing systems and processes. Various machining practices are being proposed as sustainable and require careful investigation. The current sustainability assessment models (e.g., Life Cycle Analysis [LCA]) present a holistic approach without much focus on process specific details. This project presents a more flexible "-XSI' approach for defining sustainability indices where X can be a sustainability perspective (e.g., Energy Sustainability Index, ESI). These sustainability metrics can comprehensively quantify machining processes in terms of impact on the environment and power consumption in a flexible manner. In addition, introducing the concept of normalization with respect to the "-feature-of-interest' enables a flexible rating system in terms of process types and perspectives. A user-friendly calculator is developed, which converts a set of input machining parameters into a set of measurable rating quantities and indices including but not limited to production rate, production cost, tool life/cost, energy consumption and environmental burden. This will enable the manufacturing engineer to make an informed decision about parameter selection and process design for sustainability. Machinability of titanium alloy Ti-6Al-4v is used to validate and improve the proposed approach and assess proposed practices like hybrid machining and vegetable oil lubrication.