Modeling and optimization of micro scale pocket milling operations

Abstract

Manufacturing of micro scale parts and components made from materials having complex three dimensional surfaces are used in today’s high value added products. These components are commonly used in biomedical and consumer electronics industries and for such applications, fabrication of micro parts at a low cost without sacrificing quality is a challenge. Micro mechanical milling is a viable technique which can be used to produce micro parts, however the existing knowledge base on micro milling is limited compared to macro scale machining operations. The subject of this thesis is micro scale pocket milling operations used in micro mold making which are used in micro plastic injection in mass production polymer micro parts. Modeling of pocket milling while machining of basic pocket shapes are considered first. The developed milling model is then extended to more complex mold shapes. Minimum total production time is used as the objective to solve single pass, multi pass, and multi tool problems. Case studies are presented for each problem type considering the practical issues in micro milling. A software has been developed to optimize machining parameters and it is shown that the developed pocket milling optimization model can successfully be used in process planning studies.