A Guide to Manufacturing Aerospace Parts with MJF 3D Printing

In an industry where every gram counts, parts must be optimized during product design. With conventional manufacturing methods, complex topologies may not be manufacturable without breaking them into several different pieces. In contrast, additive manufacturing pushes past this constraint by taking advantage of design for additive manufacturing (DfAM). During this process, geometrically complex parts can be consolidated into a single piece, reducing assembly time and costs.

While reducing the number of components is a key benefit of part consolidation, it’s essential to recognize that this isn’t always the only objective. For aerospace and industrial applications, manufacturers often rely on metal to produce parts due to the perceived notion of strength and durability. However, in the case of HP 3D printing, an optimized part meant transitioning from metal components to high-performance polymer parts.

Using Multi Jet Fusion (MJF), the company manufactured a drill extraction shoe, a tool critical to enabling a more efficient laser-drilling process. The tool, originally comprised of seven CNC-machined aluminum sub-components, was successfully consolidated into a single MJF-printed part using polyamide 12 (PA 12).

Although strong, aluminum carries a significant weight penalty compared to PA 12. MJF’s ability to optimize part topology for strength-to-weight ratio resulted in a 90% (575 grams to 52 grams) weight reduction. Finite element analysis (FEA) software played a critical role in optimizing these components during the design phase for weight reduction. This software enabled HP to simulate the structural behavior of the parts under various loading conditions before entering the bridge production stage of the product lifecycle. By subjecting the digital model of the component to virtual stress tests, engineers could identify areas of excessive stress and unnecessary material. The informed design modifications improved the internal flow channels by reducing turbulence in the part.

As a result, the streamlined design and production process reduced the cost of the part by 95% ($450 to $18), compared to the original CNC-machined part. Additionally, MJF’s rapid printing capabilities cut lead time from 3-5 days (CNC machining) to 24 hours.

The synergy between MJF 3D printing and part consolidation is clear when looking at the benefits of time and cost for aerospace parts. During the MJF printing process, production can be further optimized for efficiency by eliminating the need for supports during the manufacturing process. Unlike traditional manufacturing methods that require supports to maintain the integrity of intricate features, MJF builds parts layer by layer without the need for additional support structures. This not only reduces material waste but also simplifies post-processing and assembly.

A simplified assembly process translates to fewer headaches when figuring out the logistics of aerospace parts. In the aerospace industry, each part goes through strenuous validation processes to ensure material traceability, rigorous part testing, and inventory trackability. With fewer parts being shipped, fewer documents and overheads need to be tracked.

Ensuring high-quality, reliable parts is crucial in the aerospace industry, where safety and performance standards are stringent. MJF 3D printing presents itself as an ideal solution for providing exceptional material properties and consistent production quality.

MJF 3D printing is known for producing parts with superior mechanical properties. This can be largely attributed to the high-quality materials that are compatible with MJF. For instance, parts printed with PA 12 exhibit a Shore Hardness of 80D. This hardness level indicates a tough, durable surface essential for aerospace components subjected to mechanical stresses and environmental challenges. The high hardness ensures that parts can withstand impacts, abrasion, and wear which is crucial for maintaining the integrity and longevity of aerospace parts under harsh operational conditions.

Elongation at break measures a material’s ductility, indicating how much it can stretch before breaking. PA 12’s elongation at break of 20% in the X direction and 15% in the Z direction demonstrates its flexibility. This property is particularly beneficial for aerospace parts that must endure dynamic loads and vibrations without cracking or failing. The ability to absorb and dissipate energy makes PA 12 suitable for components such as brackets, housings, and connectors, where mechanical resilience is critical.

Precision is paramount in aerospace manufacturing. MJF technology offers excellent dimensional tolerance, with PA 12 parts achieving a tolerance of ±1.75 for dimensions over 80mm. This precision ensures that parts fit together accurately, reducing the need for post-processing adjustments. Accurate dimensions are crucial for components that must integrate seamlessly into larger assemblies, such as avionics housings and structural elements, ensuring proper functionality and performance.

Adopting a manufacturing process that ensures repeatability and consistency is crucial to creating critical aerospace components that meet strict aerospace standards. MJF 3D printing technology involves fusing nylon powder layer by layer using a detailing agent. This allows for precise control over part dimensions and mechanical properties, creating parts with uniform density and strength. During the design phase, engineers can optimize the topology or integrate lattice structures to reduce weight without compromising performance.

Aurea Avionics illustrates the benefits of MJF in ensuring consistent part quality by 3D printing parts for the “Seeker” unmanned aerial system (UAS). Initially, the company relied on fused deposition modeling (FDM) technology to create gimbal camera enclosure prototypes. While FDM offered a rapid prototyping solution, the parts suffered from weak mechanical properties. Given how critical this component was for protecting their drones’ imaging system, Aurea Avionics turned to HP Multi Jet Fusion as a solution. Using PA 12 as the material to create the camera enclosure, the company was able to produce higher-quality parts and decrease the need for spare parts. MJF 3D printing technology allowed Aurea Avionics to print the camera enclosure on-demand rather than preemptively producing large quantities of these parts. This systematic approach to meeting demand, along with MJF’s ability to handle complex geometries, facilitated quicker testing and iterations.