Lesson 1: AM Overview
This lesson provides a brief history of additive manufacturing (AM) including a description of the ASTM F42 standard processes, basic terminology and acronyms typically used to describe AM tools, technologies and materials. You will learn the fundamentals of AM, differences between additive and subtractive manufacturing, the benefits and industrial applications of AM and preview future advanced manufacturing technologies.
Additive manufacturing (AM) is a process of making a three-dimensional solid object of virtually any shape from a digital model
AM uses an additive process, where materials are applied in successive layers
AM is distinguished from traditional subtractive machining techniques that rely on the removal of material by methods such as cutting or milling
AM has a 26-year history for plastic objects – the capacity to make metal objects relevant to the engineered products and high tech industries has been around since 1995
Common Definitions
“The process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies“ - Wohlers Associates
“A concept whereby different processes are used to physically replicate 3D objects created by computer-aided design (CAD)” - Sculpteo
3D printing and Additive Manufacturing are not synonymous
3D Printing: “fabrication of objects through the deposition of a material using a print head, nozzle, or another printer technology”
Additive Manufacturing (AM): “process of joining materials to make parts from 3D model data, usually layer upon layer” - ISO/ASTM 52900:2015
Subtractive Manufacturing
Additive Manufacturing
Key Differences
Additive Manufacturing
In additive manufacturing, layer by layer material is added to develop a 3-D object.
This manufacturing concept is usually suitable for materials having a lower melting point, such as plastic.
Volumetric density (thus weight) of the constructive material of final component can be controlled during operation.
Very little material waste takes place in these processes.
Certain complex shapes can be easily fabricated using additive manufacturing techniques.
Structures containing fully closed internal hollow part can be produced by these processes.
These processes are applicable to a narrow range of materials.
These processes are time consuming and costly but can provide superior quality and desired property without requiring any further processing.
Advantages of AM
Redefines value and scale
Subtractive Manufacturing
In subtractive manufacturing, layer by layer material is removed from a solid block to develop a 3-D object.
This manufacturing concept is suitable for materials having high melting point, such as metallic materials.
Material density cannot be controlled during operation. Density of the object remains same with that of the initial solid block (usually a cast product).
These processes are associated with material wastage in the form of chips, scraps, dissolved ions, etc.
Subtractive manufacturing processes have limited capability in fabrication of complex shapes.
Structures containing enclosed hollow parts cannot be produced by these processes, unless joining is allowed.
These processes can efficiently handle a wide variety of materials.
These processes are time efficient and economic. These are usually suitable for mass production where requirement of product quality is not so tight.
Disadvantages of AM
Overview of AM Categories and Processes
In the next lesson, we’ll explore the definitions of each AM technology.