Essential Manufacturing

13Additive Manufacturing Processes

13.1 Introduction

Compared to some of the other processes noted here, additive manufacturing is very new. For example, a casting of a copper frog has been found that was probably made around 5000 years ago, whereas additive manufacturing only appeared commercially around the late 1980s with the introduction of stereolithography. The reason for the late appearance is that the process was only possible due to the confluence of microprocessor‐based technologies, lasers, high precision manufacturing and the ability to directly interface with computer aided design (CAD) systems that led to ‘direct digital manufacturing’ being a term used to describe the process.

Additive manufacturing equipment takes its fabrication information from a CAD model. This model may be created by practitioners from any number of disciplines such as product design engineers in the aerospace and automotive industries, architects, artists, industrial designers, sculptors, surgeons, dentists or by individual hobbyists using domestic additive manufacturing equipment. The CAD model should be volumetric, that is, a solid model, thus providing full three‐dimensional data for the finished object. The data in the model is generated in such a manner that a large number of horizontal slices through the model can be created. Each slice contains the data required for the additive manufacturing equipment to lay down or cut through one layer of fabrication material. The height of these ...