3D Printing for Complex Geometries

Due to its enormous potential in the production of next-generation objects, research interest in the 3D printing of complex geometries has increased exponentially in recent years. Since making such intricate pieces using normal techniques is difficult, researchers have now created new 3D printing methods for creating complex-shaped 3D composite structures.

This means that the manufacturing process no longer has to define the complexity of a structural component. Instead, it will define the product’s desired functionality and design. 3D printing will be especially used in design construction by allowing more accurate and faster construction of complex geometric structures that have already been designed. It will also reduce the cost of labor and may be sustainable in that it produces less waste. It may even go as far as enabling construction to proceed in dangerous or harsh places that may not be conducive for a full human workforce, such as in outer space. Indeed, it’s effects are far reaching in the field of design and construction.

In 2014, a team of engineers used 3D printing to create a steel node for a lightweight structure. The project was said to have tremendous impacts on the entire construction process by cutting cost, reducing waste, and somehow managing to make the design seem even more sophisticated. Various companies are working on different projects to create 3D printers large enough to create full external and internal walls of a building, in under 24 hours. That is how far 3D printing is going in the construction sector, and with the creation of new, more complex geometric forms, the full intensity of it is still yet to be felt.

3D Printing And Complex Geometries

Industrial 3D printing means that the complexity of a component is now determined by the product’s desired functionality and design, rather than the production technique. With traditional manufacturing techniques like milling, turning, or casting, complex geometries like three-dimensional structures with undercuts or cavities are often impossible to produce or can only be done at disproportionately high prices. Remember the Sydney Opera House? Yeah it took 14 years to build, and blew past the initial budget by well over 1400% because of its complex geometry.

Today, additive manufacturing technology can create any shape that can be created in a 3D CAD application. Even when creating hollow buildings, there are hardly any limitations. The reason this works is that the content is only added where it is required. With additive manufacturing, designers have the most geometrical freedom possible, yet intricacy has little bearing on production costs. Due to less material use, prices are frequently even greatly reduced.

In reality, most majority of natural structures have complex geometries, intricate perforations, or irregular surface morphology. These structures can serve as a micro-reactor, porous scaffold, energy absorber, or light filler. Complex topological structures may now be efficiently and precisely manufactured by stacking layered materials thanks to the rapid advancement of 3D printing. Current design techniques of complex topological structures are faced with new demands and obstacles as a result of unique manufacturing technology and application backdrop.

Tools Used For Complex Geometries Design

The technique of computer-aided design (CAD) is a useful tool for creating models for 3D printing. The two most often used techniques for representing 3D geometry are mesh models and parametric models. Nonetheless, not all complex topological structures can be designed using them. Many meshes will be used to approximate the planned model, which is highly resource-intensive, in order to produce correct modeling results. Also, merging the entire geometry will require dozens of parametric surfaces, which could have an adverse effect on the outcomes.

Technologies Used in 3D Printing of Complex Geometries

By adding layers of material throughout the additive 3D printing process, a 3D object is created. Subtractive manufacturing methods, on the other hand, involve cutting a final design from a larger block of material. As a result of 3D printing, very little material waste occurs. Listed below are some of the commonly used 3D printing methods for complex structures.

Sintering 

Sintering is a technique for producing high-resolution objects by heating the material, but not to the point of melting. Whereas thermoplastic powders are used for selective laser sintering, metal powder is utilized for direct metal laser sintering.

Melting 

Powder bed fusion, electron beam melting, and direct energy deposition are three 3D printing processes that use high-temperature melting to create objects by melting the components together.

Stereolithography

To make parts, stereolithography uses photopolymerization. Using the appropriate light source, this method selectively interacts with the material to cure and solidify a cross section of the product in small layers.

3D Printing Process

There are several processes adopted during the 3D printing of complex geometries. Some of them are:

Binder Jetting

Binder jetting involves the application of a thin layer of powered material, such as metal, polymer sand, or ceramic, onto the build platform. Next, print heads apply drops of adhesive to bind the material’s particles together. Layer by layer, the part is constructed using this method, and afterward, post-processing may be required to complete the build. Metal pieces can be thermally sintered or penetrated with a metal that has a low melting point, like bronze, as examples of post processing, while ceramic or full-color polymer parts can be saturated with cyanoacrylate adhesive. Large-scale ceramic molds, full-color prototypes, and 3D metal printing are just a few of the uses for binder jetting.

Direct Energy Disposition

In direct energy deposition, wire or powder feedstock is fused as it is deposited using focused thermal energy such as an electric arc, laser, or electron beam. To build a layer, the procedure is traversed horizontally, and to build a portion, layers are piled vertically. Metals, ceramics, and polymers are just a few of the materials that can be employed with this method.

Material Extrusion

The process of material extrusion, also known as fused deposition modeling (FDM), involves feeding a spool of filament through a heated nozzle into an extrusion head. The build platform then lowers in preparation for the subsequent layer after the extrusion head heats, softens, and deposits the heated material at predetermined positions.

Although this method is affordable and has short lead times, it also has poor dimensional accuracy and frequently needs post processing to give a smooth finish. The parts produced by this method also have a propensity to be anisotropic, which means that they are weaker in one direction and unsuitable for demanding applications.

Material Jetting

Similar to inkjet printing, material jetting works by depositing layers of liquid material from a print head or print heads instead of ink on a page. The layers are then allowed to cure before the procedure is repeated for the following layer. Although support structures are needed for material jetting, they can be created of a water-soluble material that can be removed once the build is finished.

Material jetting, a precise procedure, is one of the most expensive 3D printing techniques, and the items often wind up being brittle and deteriorating over time. The production of full-color parts in a range of materials is nevertheless possible using this method.

Power Bed Fusion

In the process known as “powder bed fusion,” heat energy (such as a laser or electron beam) selectively melts portions of a powder bed to produce layers, which are then layered upon one another to make a part. One thing to keep in mind is that PBF includes both melting and sintering. All powder bed systems operate in essentially the same way: a recoating blade or roller applies a thin layer of powder to the build platform; next, a heat source scans the powder bed surface, selectively heating the particles to cause them to bind. When the heat source has finished scanning a layer or cross-section, the platform descends to make room for the procedure to begin again on the following layer.

Sheet Lamination

Laminated object manufacture (LOM) and ultrasonic additive manufacturing are two different types of sheet lamination technologies (UAM). Although UAM welds thin metal sheets with ultrasonic technology, LOM uses alternate layers of material and glue to build objects with a pleasing appearance. Using titanium, stainless steel, and aluminum, UAM is a low temperature, low energy method that can be used for printing complex geometries.

VAT Photopolymerization

The two methods of VAT photopolymerization are stereolithography (SLA) and digital light processing (DLP). Both of these procedures employ a light to selectively cure liquid resin in a vat, building pieces one at a time. Whereas DLP flashes a single picture of each entire layer onto the surface of the vat, SLA uses a single point laser or UV source for the curing process. To increase the robustness of the pieces, parts must first be cleansed of extra resin after printing and then subjected to a light source. A higher grade finish can be produced by using further post-processing after removing any support structures.

These procedures may produce precise details with a smooth finish, making them ideal for prototype production and items with a high degree of dimensional precision. The pieces, meanwhile, are less suitable for functional prototypes because they are more brittle than those made using fused deposition modeling (FDM). Also, as exposure to UV light from the sun may cause the color and mechanical qualities of these parts to deteriorate, they are not recommended for outdoor use. The necessary support structures could potentially leave imperfections that call for post-processing.

Applications of 3D Printing

A variety of sectors can benefit from 3D printing because of its versatility, some of them are:

Aerospace 

The capacity to produce light, yet geometrically complicated parts, like blisks, makes aerospace 3D printing popular throughout the aerospace (and astrospace) industry. Due to the ability to construct an object as one complete component via 3D printing, lead times and material waste are reduced when compared to traditional manufacturing methods.

Automobile Industry 

Since 3D printing naturally reduces weight and costs, the automobile sector has embraced it. Rapid prototyping of novel or customized components is additionally made possible for testing or small-scale production. Hence, for instance, if a certain part is no longer available, it can be made as part of a small, custom run, including the production of spare parts. In contrast, objects or fixtures can be printed over night and prepared for testing before a larger manufacturing run.

Medical

Making custom implants and gadgets using 3D printing has applications in the medical field. For instance, a digital file that is matched to a scan of the patient’s body can be used to quickly produce hearing aids. Costs and production times can both be significantly decreased using 3D printing.

Rail

Applications for 3D printing in the rail sector include the production of specialized items like arm rests for drivers and housing covers for train couplings. The rail industry has utilized the method to repair deteriorated rails in addition to creating custom pieces.

Robotics

The robotics business is an excellent fit for 3D printing because of its quick manufacturing, flexibility in design, and simplicity of design customization. This involves efforts to develop customized exoskeletons and quick, effective robotics.

Benefits of 3D Printing For Complex Geometries

The advancement of 3D printing technology may democratize the production of things. Larger production projects will be possible thanks to quicker printers, and as 3D printing costs fall, more people will be able to use it in residential, educational, and other settings. Some of the benefits of 3d printing include:

• Cost-effective creation of complex geometry

With the aid of this technology, it is possible to easily create custom geometric parts with increased complexity. Since no additional material is required, 3D printing can occasionally be less expensive than subtractive production techniques.

• Low initial costs

Since no moulds are needed, the expenses of this manufacturing technique are quite affordable. The cost of a part is directly correlated with the quantity of materials used, the time required to construct the part, and any necessary post-processing.

• Fully customizable

Since the process is based on computer-aided designs (CAD), any product modifications can be easily made without having an impact on the manufacturing cost.

• Ideal for rapid prototyping

This method is perfect for prototyping because it allows for small batches and in-house production. As a result, products can be made more quickly than with more conventional manufacturing techniques and without relying on external supply chains.

• Enables the production of pieces with particular characteristics

Although metals and plastics are the most typical materials utilized in 3D printing, there is still room to produce parts from custom-made materials that have certain needed features. Hence, parts can be made for particular applications with better strengths, water resistance, or heat resistance, for example.

Got a project you need professionals for? Let's help you get started on it! You can speak with our professionals at JPC Design Consortium to get you started on your project today. We also give consultation services just in case you need some more information for your project. Contact us right away.