This document provides an overview of additive manufacturing (AM) including its history, benefits, processes, and classification. It discusses how the term "rapid prototyping" became inadequate as improvements allowed AM to produce final products. AM builds parts layer by layer directly from 3D CAD files without requiring process planning. Key benefits include speed, ability to create complex geometries, and reduction in processes and resources compared to CNC machining. AM processes are classified based on the technology used such as lasers or extrusion, or the type of raw material input like liquids, particles, molten materials, or solid sheets.

1. Subject: Digital Fabrication
Department of Mechanical Engineering
Name Gourav Tiwari
Designation Assistant Professor
Branch Mechanical Engineering
Institute VNR Vignana Jyothi Institute of Engineering
and Technology, Hyderabad
Year/semester III Year B.Tech I Semester
Subject Code 5ME71
Topic Introduction to Additive Manufacturing
Sub. Topic Introduction to AM, AM evolution, Benefits
of AM, Distinction Between AM and CNC
Machining, The Use of Layers,
Classification of AM Processes

2. Introduction to AM
1. The term Rapid Prototyping (or RP) is used in a variety of industries.
2. Improvements in the quality of the output from these machines have meant
that there is a much closer link to the final product. So it is not possible for
us to label them as “prototypes.”
3. This term becomes inadequate.
4. A recently formed Technical Committee within ASTM International agreed
that new terminology should be adopted.
5. The basic principle of this technology is that a model, initially generated
using a three-dimensional Computer Aided Design (3D CAD) system, can be
fabricated directly without the need for process planning
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3. …………..
6. Parts are made by adding material in layers, each layer is a thin cross-
section of the part derived from the original CAD data.
7. Speed, feed, thickness, dimensional accuracy
8. Models were quickly employed to supply information about what is known
as the “3 F’s” Form, Fit, and Function.
9. Finally named as Additive Manufacturing.

4. Evolution of Additive Manufacturing
1. Automated Fabrication (Autofab)
This term was popularized by Marshall Burns in his book of the same name,
which was one of the first texts to cover this technology in the early 1990s
2. Freeform Fabrication or Solid Freeform Fabrication
3. Additive Fabrication, is a term that was popularized by Terry Wohlers, a well-
known industry consultant in this field and who compiles a widely regarded
annual industry report on the state of this industry.
4. Layer-based Manufacturing
5. Stereolithography or 3D Printing
6. Rapid Prototyping

5. The Generic AM Process
1. CAD Model
2. STL convert
3. File transfer to machine
4. Machine setup
5. Build
6. Remove
7. Post-process
8. Application

6. Benefits of AM
1. Rapid
2. 3D CAD Model – WYSIWYG
3. AM – WYSIWYB
4. Seamless
5. The number of processes and resources required can be significantly
reduced when using AM
6. No process planning
7. Reduction of various operations

7. Distinction Between AM and CNC Machining
1. Material
2. Speed
3. Complexity
4. Accuracy
5. Geometry
6. Programming

8. The Use of Layers
• AM part manufacturing use layers of finite 2D cross-sections to build 3D model.
• Almost every AM technology builds parts using layers of material added
together.
• Gaps between 2D layers can be represented precisely.

9. Classification of AM Processes
• Basis: 1. Process – Lasers, Printer Technology, Extrusion Technology……….
2. According to the type of raw material input.
• Liquid Polymer Systems
• Discrete Particle Systems
• Molten Material Systems
• Solid Sheet Systems