Additive manufacturing (AM), commonly referred to as 3D printing, has revolutionised the manufacturing landscape. It offers unprecedented opportunities for innovation, efficiency, and sustainability. Metal additive manufacturing, in particular, has expanded the possibilities for creating durable, high-performance parts. Unlike traditional manufacturing methods, which involve cutting or shaping materials, additive manufacturing builds objects layer by layer based on a digital 3D model.
This method enables the creation of highly complex designs with minimal material waste, making it an attractive solution for industries ranging from aerospace to healthcare. As technology continues to evolve, it’s reshaping how products are designed, prototyped, and produced on demand, ushering in a new era of manufacturing.
Difference Between Additive and Subtractive Manufacturing
When I first started learning about manufacturing, the difference between additive and subtractive methods struck me. Traditional manufacturing involves taking a material—such as metal, plastic, or wood—and removing chunks to reveal the final product. This is known as subtractive manufacturing.
On the other hand, additive manufacturing works by building material up layer by layer, rather than cutting away. This process reduces waste significantly, as only the material needed to form the object is used.
Here’s a quick comparison between the two:
| Feature | Additive Manufacturing (AM) | Subtractive Manufacturing |
| Material Usage | Builds up material layer by layer, reducing waste | Removes material, creating significant waste |
| Speed | Faster for prototypes and complex parts | Slower, especially for complex geometries |
| Design Flexibility | Allows intricate and complex designs | Limited by the tooling and material properties |
| Precision | Highly precise, suitable for complex geometries | Less precise, especially for intricate designs |
| Material Types | Works with a variety of materials (metals, plastics, ceramics) | Primarily metals, plastics, and wood |
I’ve seen how much waste is generated in automotive manufacturing where hundreds of kilograms of material can be lost in a single car part. With additive manufacturing, that material is used efficiently, leading to both cost savings and environmental benefits.
3D Printing vs. Additive Manufacturing: What’s the Relationship?
The terms 3D printing and additive manufacturing are often used interchangeably, but they have different connotations.
- 3D Printing is commonly associated with consumer-level machines used for small-scale, hobbyist projects or simple prototypes.
- Additive Manufacturing (AM), on the other hand, is the term adopted by industries like aerospace, automotive, and healthcare to refer to industrial-scale production methods used to create functional parts.
| Term | Common Usage | Industry Focus |
| 3D Printing | Used for prototypes and small-scale work | Mostly consumer and hobbyist-focused |
| Additive Manufacturing | Used for industrial-scale applications | Focuses on high-performance and end-use parts |
In the early 2010s, there was debate over whether to call it 3D printing or additive manufacturing in industrial contexts. AM won out due to its more formal and professional connotation, representing a high-performance process used for manufacturing functional parts.
The Evolution of Terminology in 3D Printing and Additive Manufacturing
In the early days of 3D printing (1980s to 1990s), the technology was mainly used for rapid prototyping. At that time, the term rapid prototyping was more fitting because it highlighted the speed of producing prototypes.
As technology improved and AM began to create end-use parts—like metal components for airplanes—the term additive manufacturing emerged to reflect the increased precision and industrial capabilities. By the 2000s, AM was no longer limited to prototypes but was producing parts for industries that required high precision, such as aerospace and medical devices.
The Additive Manufacturing Process: Key Principles and Benefits
Additive manufacturing is a process that builds objects layer by layer, offering design flexibility, precision, and a level of complexity not possible with traditional manufacturing.
Key Benefits of Additive Manufacturing:
- Complexity Without Extra Cost: AM allows for the creation of intricate internal structures or geometries that would be difficult or impossible to produce with subtractive methods.
- Reduced Waste: Unlike traditional methods where material is cut away, AM only uses the material required to form the object, resulting in less waste and lower material costs.
- Design Flexibility: AM allows designers to create parts with internal channels, custom geometries, and complex shapes that would have otherwise required costly tooling or molding.
Design Flexibility and Freedom: Revolutionising Product Development
Additive manufacturing has truly opened the doors to unlimited design possibilities. With AM, designers can create complex lightweight structures that are both durable and cost-effective.
For example, GE Aviation used AM to create a fuel nozzle for its LEAP engine. By using 3D printing, GE consolidated 20 separate parts into one, reducing weight and improving fuel efficiency.
| Industry | AM Application | Benefit |
| Aerospace | Fuel nozzle for LEAP engine | Reduced weight, improved fuel efficiency |
| Automotive | Lightweight exhaust manifolds | Enhanced performance, reduced material waste |
| Healthcare | Custom medical implants | Perfect fit, improved patient recovery |
Materials Behind Additive Manufacturing
One of the most exciting aspects of additive manufacturing is its versatility with materials. While plastics like ABS and PLA are used for consumer-level 3D printing, industrial-grade AM uses a wide range of materials:
| Material | Common Applications | Benefits |
| Plastics (ABS, PLA) | Consumer goods, prototypes, toys | Affordable, versatile, and easy to work with |
| Metals (Stainless Steel, Titanium) | Aerospace, automotive, medical parts | Strong, durable, corrosion-resistant |
| Ceramics | Dental implants, jewelry | High precision, biocompatible |
| Composites | Aerospace, automotive, tooling | High strength-to-weight ratio, customisability |
I’ve witnessed aerospace companies like Boeing and Airbus using titanium in AM to create lightweight yet strong parts, a practice that is revolutionising the design and functionality of aircraft.
Custom Manufacturing with 3D Printed Parts: A Material Advantage
The ability to use custom materials is one of the most exciting advancements in additive manufacturing. For instance, in healthcare, titanium is being used to print custom implants that are patient-specific.
- Custom Bone Replacements: AM allows surgeons to print bone replacements tailored to the patient’s anatomy, leading to better recovery and faster healing.
Categories of Additive Manufacturing Processes
Additive manufacturing isn’t a single process but a category of seven distinct methods, each with its own strengths. The ISO/ASTM 52900-15 standard outlines these processes:
| Process | Common Material | Key Strength | Applications |
| Vat Photopolymerisation (VPP) | Resin | High precision, ideal for small, detailed models | Jewelry, dental, prototype development |
| Material Jetting (MJT) | Liquid materials | Multi-material capability, high-quality finish | Medical devices, high-detail prototypes |
| Binder Jetting (BJT) | Powdered materials | Full-color parts, good for metal sandcasting | Automotive parts, full-color prints |
| Powder Bed Fusion (PBF) | Metals (Titanium, Steel) | Complex geometries, structural integrity | Aerospace, medical devices, structural parts |
| Material Extrusion (MEX) | Thermoplastics (ABS, PLA) | Widely accessible, low-cost production | Rapid prototyping, consumer goods |
| Directed Energy Deposition (DED) | Metals | Repair and rework of parts, precision welding | Aerospace, tooling repair |
| Sheet Lamination (SHL) | Sheets (paper, metal) | Low-cost prototypes, large-scale models | Automotive, rapid prototyping |
The Impact of Additive Manufacturing on Industries and Innovation
Additive manufacturing has sparked a massive shift in industrial innovation. One example comes from the automotive industry, where AM is used to create complex exhaust manifolds with internal channels that would have been impossible with traditional manufacturing methods.
Advancing Sustainable Production with Additive Manufacturing
Additive manufacturing is playing a key role in sustainability. It significantly reduces material waste compared to traditional subtractive methods and enables companies to use recycled materials.
| Sustainability Benefit | Impact |
| Reduced Material Waste | Only the required material is used, reducing scrap |
| Recycled Materials | Enables circular manufacturing, using recycled plastics and metals |
| Lower Energy Consumption | Less energy is needed compared to traditional methods |
Working on a sustainable housing project, I saw how recycled materials were used in 3D printing construction components, reducing waste and supporting green building practices.
The Future of Additive Manufacturing: What’s Next?
Additive manufacturing is quickly becoming more than just a prototype tool. It’s now used in mass production for industries like aerospace and medical devices. As the technology matures, the cost of industrial 3D printers is expected to decrease, making AM accessible to more industries and smaller businesses.
