In recent years, 3D printing (also referred to as additive manufacturing or digital fabrication technology) has emerged as a truly innovative, powerful, flexible, and versatile technique widely used in many countries, especially in manufacturing.
This fast-emerging technology can enable engineers to create three-dimensional (3D) structures or physical objects from a computer-aided design (CAD) model by successive addition of materials. It opens new opportunities and gives hope to many possibilities for companies looking to improve manufacturing efficiency.
3D printing technology can revolutionize industries and change the production line by increasing the production speed while reducing costs. Consumers can have greater input in the final product and request to have it produced to fit their specifications.
Since 3D printing technology facilities can be located closer to the consumer or nearer to the end destination, it allows for a more flexible and responsive manufacturing process, greater quality control, and easier logistics, saving energy and time.
Today, 3D printing is no longer limited to prototyping usage but is increasingly being used to make a variety of products. Conventional thermoplastics, ceramics, graphene-based materials, and metal are commonly used to meet consistent specifications and build high-quality products. This post will explore some of the best used raw materials in 3D printing.
1. Metals
Metal 3D printing is gaining more attention in aerospace, automobile, medical application, and manufacturing because of metals’ excellent physical properties, such as high stiffness, resilience, low density, high recovery capacity, high corrosion, elongation and heat, and temperature resistance. They can withstand high stresses and high operating temperatures. The examples of metals being used in 3D printing are aluminum alloys, cobalt-based alloys, nickel-based alloys, stainless steels, titanium alloys, copper brass. Silver and gold are applied as well. Cobalt-based alloy is suitable for dental application, while nickel-base alloys are commonly used for aerospace parts. Metals are usually applied in powder form.
2. Polymers
3D printing is widely used to produce polymer components, from prototypes to functional structures with complex geometries. By using fused deposition modeling (FDM), it can form a 3D printed through the deposition of successive layers of extruded thermoplastic filament, such as polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polypropylene (PP), or polyethylene (PE).
There are many properties of polymers that can contribute to how well the parts are printed. The properties of interest for how well polymer prints include glass transition temperature (Tg), melting temperature (Tm), and the coefficient of thermal expansion (CTE). Lately, thermoplastics filaments with higher melting temperatures such as PEEK and PMMA are used. 3D printing polymer materials in the liquid state or with a low melting point are widely used for making biomaterials, orthopedic implants, and medical devices due to their low cost, low weight, and processing flexibility.
Below is a list of some of the commonly used FDM plastic materials for 3D printing.
- Polylactic acid (PLA) plastic – best known as a biodegradable polymer produced from renewable sources like corn starch.
- Acrylonitrile Butadiene Styrene (ABS) plastic – Particularly favored for its rheological properties, creating relatively smooth surfaces.
- High-Impact Polystyrene (HIPS) plastic – Its primary use is often creating rafts and support material in contact with the object being printed.
- Thermoplastic Polyurethane (TPU) elastomer – It is a block copolymer made of long nonpolar regions that slide past each other easily, giving it flexibility, and short polar regions that crystallize, maintaining a set structure.
- Polyethylene Terephthalate (PET) plastic – commonly recognized polymer used in plastic drink bottles and in polyester fabric.
- Nylon – Nylons are generally resistant to solvents like gasoline, acetone, and benzene but degrade when exposed to acids.
3. Ceramics
Ceramic is a nonmetallic, inorganic solid, which has exceptional and diverse physical and chemical properties. It is a versatile material with high mechanical strength and hardness, good thermal and chemical stability, chemical inertness, low density, low electrical and thermal conductivity, viable thermal, optical, electrical, and magnetic performance. The introduction of 3D printing into ceramic components’ manufacturing offers entirely new possibilities in biomedical engineering, electronics, aerospace, chemical industry, and machinery.
4. Composites
Composite materials such as carbon fibers reinforced polymer composites and glass fibers reinforced polymer composite has exceptional versatility, low weight, and tailorable properties. Carbon fiber reinforced polymers composite structures are widely used in the aerospace industry because of their high specific stiffness, strength, good
corrosion resistance, and good fatigue performance. Meanwhile, glass fibers reinforced polymer composites are used for various applications in 3D printing due to the cost-effectiveness, high thermal conductivity, and relatively low coefficient of thermal expansion.
5. Special materials
- Food: 3D printing can process and produce the desired shape and geometry by using food materials like chocolate, meat, candy, pizza, spaghetti, sauce, etc. 3D printing in food items allows customers to adjust the ingredients materials without reducing the ingredients’ nutrients and taste.
- Textile: This technique enables users to design and fabricate soft and flexible textile variations, using a consumer-grade fused deposition modeling (FDM) 3D printer. It allows users to employ materials with various colors and/or properties when designing a pattern, and to prototype an interactive object using different off-the-shelf materials such as a conductive filament.
Let’s sum up. The majority of materials used for 3D printing are plastics and metals. Ceramics and composites are used as well, besides a wide variety of materials are investigated and tested for 3D printing. A wide range of plastics can be used for 3D printing, depending on the applied AM technology. In recent years, new filaments are developed based on polymer composites, such as the PLA filled with wood, bamboo, cork, copper, and bronze.
