Mechanical Testing of 3D Printed Parts and Materials

A New Approach to Product Development & Rapid Prototyping

The procedure of manufacturing objects by depositing successive layers upon layers of material, based on 3D digital CAD models, is called Additive Manufacturing (AM) or simply 3D-printing. Fused Deposition Modeling (FDM) technology is one of the most widely used technique in additive manufacturing. A range of other manufacturing materials can be used for 3D printing that include nylon, glass-filled polyamide, epoxy resins, wax, and photopolymers. FDM-based polymer product manufacturing has increased in recent times due to the flexibility it offers in the production of polymer and fibre-based composite parts. FDM-based polymers have the potential to be used in all applications, currently they are primarily used in automotive, aerospace and biomedical applications.

Additive Manufacturing involves a series of processes, from ideation and design development to final product manufacturing using a specialized printer. The different steps depend on the type of manufacturing method and the material type. The primary processes and steps involved are however mostly common and remain the same for different types of manufacturing applications. The steps involved in an AM process are as shown below;

3D Printing Process

Fused Deposition Modeling (FDM)

FDM is the method of choice for manufacturing of 3d printed polymer parts and components due to its simple process, low economic cost and predictable material properties. FDM is already used in the material extrusion manufacturing process for various thermoplastic polymers. Some common thermoplastic filaments used in FDM are acrylonitrile butadiene styrene (ABS), polypropylene (PP), polylactide (PLA), polyamides (PA) like Nylon, polyether-ether-ketone (PEEK) etc. The FDM process consists of the polymer being extruded and deposited in a successive layer by layer method. FDM manufactured polymer parts and components exhibit good mechanical properties, surface finish, and manufacturability. The matrix material used in the FDM process is in the form of a 1.75mm to 2.85 mm filament wound on a spool. The filament is fed into the printer head where it is heated and melted above its glass transition temperature (Tg). The plastic melt is then passed to the nozzle and deposited layer by layer.

FDM of Fibre-Reinforced Polymers

The strength of polymeric materials can be significantly improved through reinforcement by fibres. Fibre-reinforced polymers manufactured using 3d printing technique is gaining traction. Fibre-matrix interaction and porosity are important considerations to be addressed in 3d printing of polymeric composites. FDM is currently the most preferred method for the production of polymeric fiber composites due to its material flexibility, and consistent properties.

Although the 3d printing additive manufacturing method is a sophisticated process for producing materials, and readily usable components and parts, the field service material behaviour of these printed parts is highly complicated. These properties are influenced by several process parameters such as filament material, temperature, printing speed. The material behaviour is highly anisotropic and is governed by the microstructure produced while depositing the layers and the ambient environment. The resulting material behaviour can be described using stress–strain relationships and is critical in the Finite element analysis and stress analysis of models. AdvanSES has full capability to test these complex materials and their behaviours using an array ot techniques. Mechanical testing of 3D printed parts and materials is now a key part of our portfolio of services