Hybrid Additive Manufacturing Debate

Abstract

There are two terms in additive manufacturing (AM): shaping and post-processing. These are so prevalent that everyone knows and uses them when required. This has led to their use for different purposes, giving rise to not a single meaning for each term. This has brought into question how much post-processing is acceptable to define AM. This question is tied to another question: what AM stands for—making either all parts or increasingly complex parts. The aim is to answer these questions.

The merits of these questions can be better understood if opposing views are instantly available to argue from both sides. Therefore, the present book is written in the form of conversations between two imaginary researchers, named R1 & R2, emphasizing storytelling. It is divided into two parts. The first part consists of five sections; the second one, four sections. These sections are titled Dialogue 1 to Dialogue 9. There are 726 conversations that are continuously numbered. Numbering allows them to be tracked independently of a section number. References for all sections are given together at the end.

The title ‘Hybrid additive manufacturing debate’ implies that the conversations are only about hybrid AM (HAM), but this is how it started. Therefore, the first section, i.e., Dialogue 1, is named Hybrid AM. After that, the conversations involved several questions that are not confined only to HAM. Some of the questions are related to the following: the role of post-processing, how much post-processing converts AM into HAM, the difference between simple and complex parts, how to define a complex part, which parts should be preferred in AM, which particular problem defines AM, how AM is different from other techniques, why simple parts should not be fabricated using AM, how the boundary between AM and HAM can be defined, what is the role of AM in shaping, what is shaping, what is the role of manufacturing, is there any difference between AM and an AM process, is AM near-net-shaping technology, is a part sustainable, etc.

The conversations, heated exchanges, arguments, counter-arguments, examples, counter-examples, agreement, and disagreement led to a conclusion. The conclusion is that a structural framework is needed—one that defines the external and internal boundaries of AM. The external boundary is to distinguish AM from HAM; the internal one, simple shapes from complex shapes.

The framework titled ‘Twin-boundary framework for AM’ is presented in Part 2. The framework has two boundaries or pillars. Dialogue 6 informs about it. Dialogue 7 gives its general description. Dialogues 8 & 9 give detailed descriptions of the first and the second boundary, respectively. The conversations that led to the framework are given in Part 1. Dialogue 2 deals with the meaning of shaping. Dialogue 3 tries to reason why AM should be treated differently from other techniques. Dialogue 4 discusses why simple AM parts should not be made and when they should be made. Dialogue 5 reasons the same from a sustainability perspective.

A logical decision tree is added.

The conversations sometimes go slow, but it helps when the logic is counterintuitive. I hope this book will be helpful to everyone.