Plastic is the most common material in 3D printing. Melting plastic and manipulating it to create the desired three-dimensional object makes sense, and it’s easy enough that anyone can do it. However, can the same be done with other materials?
3D printers don’t only use plastic. They can use various metals, including titanium, aluminum, and stainless steel. They can also use composite materials that include fibers such as Kevlar, Fiberglass, and carbon fiber. Other materials include ceramics, nitinol, and graphite.
Read on for a comprehensive guide to the materials that 3D printers use, including the qualities that make different materials suitable for various 3D printing applications.
The Materials That 3D Printers Use
Most hobbyists and individual 3D printers use plastic to create 3D prints. However, 3D printing is a vast field with applications in multiple industries.
Industrial 3D printers use less common materials like metals, ceramics, and advanced forms of plastic.
All 3D printing materials can be classified into the following categories:
- Composite materials
- Hybrid materials
- Graphite and graphene
Each of the materials in the classes above is suitable for a particular application.
I’ll explain the characteristics of each material below and discuss the qualities that make it preferred for use in 3D printing.
Plastic is the most common material for 3D printing for multiple reasons.
Firstly, it’s easy to melt and doesn’t require a lot of heat compared to other materials. It’s also easy to manipulate into the required shape. Moreover, it is widely available and affordable.
On a more technical level, plastic comes in a wide variety of forms. As such, you can easily find a form of plastic suitable for the sort of material you want to print.
Thanks to the variety of plastics, you can optimize for multiple properties, including:
- Tensile strength. The higher the tensile strength, the higher the stress your end product can withstand without breaking.
- Elongation. This property indicates how flexible your end product is.
- Impact strength. This quality defines the behavior of your end product when it’s dropped or exposed to other forms of shock.
Additionally, plastics allow you to work with multiple techniques, each suited for a certain quality in the end product.
For personal use, you can use plastic to make whatever you like, from a simple tool to a realistic version of the Millennium Falcon from Star Wars.
In manufacturing, 3D printing with plastics is appropriate for the following applications and more:
- The rapid creation of affordable prototypes and proof-of-concept models.
- Functional prototyping.
- Dental applications.
- Jewelry prototyping.
- Making models and props.
As far as 3D printing materials go, metal is one of the most expensive and complex. It’s decidedly out of reach for most hobbyists and even some companies.
For one, the heat levels required to melt metal so a printer can form it into the required shape are very high. Additionally, getting a 3D printer that can use metal is costly. Even small bits like 3D printer nozzles cost much more than those in a 3D printer that uses plastic.
Nevertheless, the use of metal in 3D printing has been growing. It can bring massive benefits for companies, including shorter manufacturing times and lower costs.
Already, 3D printing with metal has been a significant advantage in the following applications:
- Manufacturing air travel equipment in shorter times and with simplified workflows.
- Producing higher quantities of jewelry in shorter time frames.
- Using powdered metal to make medical devices.
A particularly striking example of metal in 3D printing is in the manufacture of embroidered bracelets using steel and copper. Using a 3D printer to engrave intricate details on the bracelet is much more convenient than manual labor.
The following types of metal are typical in 3D printing:
- Nickel Alloys
- Tool Steel
- Stainless Steel
- Gold and Silver
Check this video of metal 3d printing:
I’ll briefly go over each metal below.
If you want to print an object that requires strength, titanium is the metal to choose. The metal has many admirable qualities, including:
- It’s highly resistant to heat.
- It’s resistant to oxidation and corrosion by acids.
- It’s lightweight.
- It affords increased resolution and complexity in design.
Titanium is suitable for fields such as space exploration, but using it to 3D print is incredibly costly.
Aluminum is the metal to use if you need to make thin metal items. Some of the advantages of 3D printing with aluminum include:
- It has an excellent strength-to-weight ratio.
- Combined with silicon or magnesium, it has high chemical resistance and can withstand harsh environmental conditions.
- Aluminum alloys are generally lightweight.
Nickel alloys typically go through a thorough preparation process to make them ready for use in 3D printing. Sometimes, they are mixed with ceramic elements to improve their flow during printing and overall performance.
Some of the advantages of using nickel alloys in 3D printing include:
- It has high mechanical strength and heat-creep resistance, allowing products to keep their shape even under high stress and temperature levels.
- It has a high resistance to oxidation and corrosion.
- It has comparatively better tensile strength.
Tool steel is a good option when you need to print mechanical tools or other items that need to be tough. Tool steel is durable and malleable, making it suitable for such applications.
Additionally, you can use it to make structures with advanced thermal control that can support complex geometries.
Stainless steel is perfect where strength and detail are priorities. It has the following advantages:
- Corrosion resistance.
- You can treat it with heat to improve strength and hardness.
- High strength and ductility.
Gold and Silver
3D printing using gold and silver is done chiefly in the jewelry industry. These metals have high electrical conductivity and can withstand extremely high temperatures.
However, using gold and silver in 3D printing is difficult. To begin with, they require very high temperatures. Also, their high reflectivity and thermal conductivity make it challenging to use lasers on them.
On the whole, it’s quite an expensive process.
Though ceramics require very high temperatures to melt and reform, you can use them with 3D printers.
Before 3D printing with ceramics was possible, it was challenging to fabricate complex shapes using ceramics such as porcelain and earthenware.
Ceramic 3D printing is preferable for the following advantages:
- High resistance to abrasion, heat, and acid corrosion.
- More excellent durability than both metal and plastic. Ceramics can withstand significant pressure.
- High chemical resistance.
- Good electrical insulation.
- High strength-to-weight ratio.
Already, 3D printing with ceramics is standard for the following industrial applications:
- Making diagnostic equipment and surgical tools. The lightness, durability, and biocompatibility of ceramics make them suitable for this application.
- Manufacturing elements in power generation and distribution systems. Ceramics are perfect because they have high electrical insulation and are wear-resistant.
- Making parts in the chemical industry. Ceramics can withstand temperature changes and corrosion.
- In the aerospace and aviation industries, ceramics can make parts such as thermal shields. Ceramics are perfect because they are lightweight and can withstand extreme temperatures.
Composite materials consist of part plastic, with the rest of the material consisting of a different substance, commonly called fiber. Standard fibers include kevlar, carbon fiber, and fiberglass. Carbon fiber is the most common. Even diamond, too hard to be used directly in 3D printing, can be used as a fiber.
These fibers can strengthen the plastic. The result is a strong material that’s also lightweight.
The type of fiber added depends on the quality you want to enhance.
You use kevlar when you need to improve the shock resistance of your final product. Fiberglass comes in handy when you need an affordable way to enhance the strength of your plastic.
According to the type of reinforcement used, composite materials can be of two types:
- Short fiber
- Continuous fiber
The 3D printer filament comes pre-mixed with the fiber in a short fiber composite material. Usually, tiny, powdered fiber pieces are combined with the plastic before manufacturers form it into a solid filament.
The fiber ratio in the composite material can adversely affect the quality of your end product. Past a certain threshold, the surface finish of your product won’t be as smooth as it should be.
The composite material’s fiber ratio also affects the filament’s strength.
In continuous fiber, the combination of fiber and plastic occurs during extrusion. The 3D printer will have two operational nozzles. One will be extruding plastic as the other extrudes the fiber.
This method of combination delivers the highest performance. However, it’s more complicated since the 3D printer has to have two nozzles. On the other hand, using the short fiber method, you don’t have to look for a particular 3D printer as only one nozzle is required.
The process can optimize for material consumption or optimize the strength-to-weight ratio.
Composite materials are commonly used to 3D print the following items:
- Lightweight machine parts, such as a bike frame
- Automotive parts
- Technical materials like high-performance thermoplastics
- Functional prototypes
A hybrid material usually consists of 70% plastic and 30% powder. The powder can come from various materials, including metal powder and dust from wood or bamboo.
The powder in hybrid materials primarily gives a desired aesthetic quality to the end product. For example, if you want to give your end product a metal finish, you can include powder from silver, bronze, or copper.
A hybrid material made of wood powder will give your product a more organic texture.
Graphite and Graphene
Graphite is a naturally occurring material you can use to make graphene. Graphene is a synthesized, pure form of carbon.
It has the following desirable characteristics:
- High electrical conductivity.
- It’s light.
- It’s easy to insulate.
Graphene performs much better than other conductors in the market, which increases its appeal.
One of the most promising industrial uses of graphene is the creation of LED lighting, which could drive a significant decrease in lighting costs by enabling mass printing of materials.
Knowing Which Material To Use for 3D Printing
There’s a wide range of materials to use in 3D printing. Some materials are cheap and readily available, such as plastic. Other materials are highly costly to purchase and require complicated setups.
Aside from the cost, the following are the most important factors when choosing a 3D printing material:
- The product you want to 3D print.
- The 3D printer you have.
The Product You Want to 3D Print
The qualities of your end product should determine the material you use. Each material has unique qualities. Moreover, you can fine-tune specific properties by mixing materials (for example, by using composite or hybrid materials).
You can describe your end product using the following properties:
- Elongation. Stretching capability or the likelihood of a material to deform.
- Impact strength. The ability to absorb shock or impact without breaking.
- Heat deflection temperature. Measures the ability of a product to be used at high temperatures without deforming.
- Tear strength. A measure of how fast tears in a plastic product grow.
- Tensile strength. A measure of how much tension a product can withstand before breaking.
- Creep. An indicator of the likelihood of a product deforming permanently when under stress.
- Compression set. A measure of the tendency of a material to return to its original shape after applying pressure.
- Hardness. The tendency of a material to resist surface deformation.
The 3D Printer You Have
The 3D printer you have will restrict the materials you can use. If you have an unlimited budget to buy a 3D printer compatible with any material, this isn’t a problem.
Otherwise, your 3D printer becomes a crucial consideration.
For example, if you want to make a composite 3D print using the continuous fiber method, you’ll need a 3D printer with two nozzles. Otherwise, you might have to use one material such as plastic.
Moreover, small things such as your nozzle material affect the material you can use. If you want to print an abrasive material, a brass nozzle won’t do because it will wear out quickly.
3D printers do not use only plastic. Though plastic is the most common 3D printing material, you can 3D print with many other materials. These include various metals, hybrid materials, graphite and graphene, and ceramics.
Different 3D printing materials have different qualities. Your choice of material should depend on the properties you want your end product to have.