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Post 2: Material used in 3d Printing
Description: Different type of Materials in their packaging. Photo: Junaidh shaik Fareedh
Material Types
At Helmholtz Institute Freiberg (hereafter known as HIF) we primarily use 3 materials on a daily basis. We also do have some experimental materials available as well, which I will explain in detail why it was chosen and why we can not use in our purpose to build drones. Let us start the topic by knowing how plastic and other materials are used in 3D printing.
Plastic and other materials are commonly used in 3D printing processes to create a wide range of objects and components. Here are some commonly used materials in 3D printing:
1. Thermoplastics:
- ABS (Acrylonitrile Butadiene Styrene): Known for its strength, durability, and impact resistance.
- PLA (Polylactic Acid): A biodegradable and easy-to-print material suitable for various applications.
- PETG (Polyethylene Terephthalate Glycol): Combines the properties of ABS and PLA, offering good strength and flexibility.
- Nylon: Provides high strength, toughness, and resistance to wear and impact.
- TPU (Thermoplastic Polyurethane): A flexible and elastic material with excellent impact resistance.
- Polycarbonate (PC): Offers high strength, heat resistance, and transparency.
- PEEK (Polyether Ether Ketone): Known for its exceptional mechanical, thermal, and chemical properties. Commonly used in aerospace and medical applications.
2. Photopolymers/Resins:
- Standard Resins: General-purpose resins available in various colors for rapid prototyping.
- Tough Resins: Enhanced mechanical properties with increased impact resistance.
- Flexible Resins: Flexible and rubber-like materials suitable for applications requiring elasticity.
- Dental and Medical Resins: Biocompatible resins designed for dental and medical applications, such as surgical guides and dental models.
- High-Temperature Resins: Resins capable of withstanding elevated temperatures for applications like injection molding and tooling.
3. Metals:
- Aluminum: Commonly used for producing lightweight parts with good mechanical properties.
- Stainless Steel: Provides high strength, corrosion resistance, and durability.
- Titanium: Offers excellent strength-to-weight ratio, biocompatibility, and corrosion resistance.
- Cobalt Chrome: Known for its high temperature and corrosion resistance, suitable for aerospace and medical applications.
- Inconel: Provides superior heat resistance and is often used in high-temperature applications.
4. Composites:
- Carbon Fiber Reinforced Polymer (CFRP): Combines the strength and stiffness of carbon fiber with the ease of printing using a polymer matrix.
- Glass Fiber Reinforced Polymer (GFRP): Offers increased strength and stiffness with the addition of glass fibers.
- Metal Matrix Composites (MMC): Reinforced with ceramic or metallic particles, enhancing properties like wear resistance and thermal conductivity.
Since we at HIF use a FDM Printer (Fused Deposition Modeling) we tend to use materials in the form of Filament that is 1.75mm in diameter.
Description: Plastic ABS Filament which is 1.75mm diameter. Photo: Junaidh shaik Fareedh
Our 3 Top Material Picks
As mentioned earlier we have 3 materials that we prefer use on our drones. First being ABS (Acrylonitrile Butadiene Styrene), then PETG (Polyethylene Terephthalate Glycol) and Onyx Tough (A Special Blend Filament from Makerbot)
The ABS is an industrial grade filament that has been used in Automotive parts for years. The Automotive industry uses them in making door covers, Car Bumpers, rear view mirror housings and other many parts. The reason why ABS is used are as follows,
UV light Shielded
Melting Temperature: 210-250°C (degrees Celsius)
Tensile Strength: 40-60 MPa (MegaPascals)
Chemically resistant to diluted acids, alkalis, and alcohols.
Low Water Absorption: 0.2-0.8% (by weight) after 24 hours of immersion
The above mentioned points are general reasons to pick ABS over other materials but the most important of them all for me will be the UV shielding and the high melting point. Let me explain, any aircraft big or small needs to be placed in direct sunlight for at least few minutes to few hours while in Use. Some plastics tend to deform or loose its strength after prolonged exposure to UV light, like, they might get brittle or some times expand in size. Therefore loosening it from the intended use.
The image to the left shows parts of two different materials and how they have deformed after prolonged usage under the Sun. The black part was printed using the material Tough (From Makerbot) which uses mostly a combination of PLA and little bit of Nylon. The material properties are said to be 2x compared to ABS and so I decided to go for it, but only after using it for almost 2 years, we realized that the Strength of the materials as good as they advertised but the material has serious deformation and discoloration under the Sun.
The material to the right in Red is made out of ABS which was printed even before the Black part was printed. And you can see the difference in Deformation between them. Even though the Red ABS part is older the dimensions and strength has been retained to most extent that the part is still usable. Unfortunately the Black part can not be used any more.
I do have a lot more to share, but now I have to get back to work. So lets meet in the next post where I will explain, how the parts printed in ABS fails too.
Next Post: How prolonged stress affects 3D printed parts and how experimental materials are chosen for testing.
In the Next post 3, I will give information on how even the ABS printed part can reach breaking point due to prolonged stress on them. This leading us to start searching for experimental materials with composites in them and how the test results proved to be.
Signing off for Today: JSF
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