In recent years, 3D printing technology has been developing rapidly, showing application potential in many fields.
Building objects layer by layer, this technology overcomes traditional manufacturing limits and enables complex structure design and production.
In the field of mechanical design and manufacturing, the application of 3D printing technology has important practical significance.
3D printing technology can shorten the product development cycle.
Traditional design needs many trials, but this technology quickly creates prototypes, enables testing, and allows customization, improving R&D efficiency.
At the same time, this technology rapidly produces personalized parts based on customers’ specific needs to meet diverse requirements.
In addition, this technology shows broad application prospects in mold making, repair, lightweight design, and material innovation.
3D printing technology overview
Additive manufacturing builds 3D objects by adding materials layer by layer.
Unlike traditional subtractive methods, 3D printing enables complex structure design and greatly expands mechanical design possibilities.
The technology uses CAD to create a model, slices it into layers, and builds the final object layer by layer with 3D printers.
There are various types of 3D printing materials, including plastics, metals, ceramics, etc., which are suitable for different application scenarios.
The process flow of 3D printing is shown in Figure 1, which mainly includes the following steps:
- Modeling. Use computer-aided design (CAD) software to create a three-dimensional digital model.
Designers can use CAD software to conduct detailed structural analysis and optimize the design to ensure the functionality and durability of the model.
For reverse engineering, digital models can be generated through 3D scanning.
- Slicing. The 3D model converts to an STL file, which slicing software like Slic3r or Cura cuts into thin layers.
The slicing software generates a print path for each layer and outputs G-code files that contain specific instructions for the 3D printer to execute.
- Printing. Load the G-code into the 3D printer, choose the material, and start layer-by-layer printing.
The 3D printer builds up the material layer by layer according to the G-code instructions, and finally forms a solid object.
- Post-processing. After printing, perform post-processing like support removal, heat treatment, polishing, and precision machining.
These steps can improve the mechanical properties and surface quality of the part to ensure that it meets the design requirements.
Innovative Application of 3D Printing Technology in Mechanical Design and Manufacturing
Design and manufacture of complex structures
3D printing optimizes material distribution, maximizes structural performance, and minimizes material use for complex topology design.
Traditional methods require assembly, while this technology enables integration and simplifies design and production.
For example, the fuel nozzle of an aircraft engine is a typical complex structural component, which contains a number of precision fluid channels.
Designers use CAD to create a 3D fuel nozzle model, and topology optimization ensures optimal performance with minimal material use.
Slicing software (e.g., Slic3r or Cura) slices the 3D model into layers and generates a G-code file with print paths.
Engineers select titanium alloy powder for its strength and heat resistance, making it ideal for aero-engine parts.
Finally, selective laser melting (SLM) technology is used for printing.
SLM technology melts the metal powder layer by layer by laser and builds up layer by layer to form the fuel nozzle object.
During the printing process, the laser beam follows G-code instructions to precisely control the melting and curing of each layer of material.
After printing, the necessary post-processing steps are carried out to improve the mechanical properties and surface quality of the part.
Personalized Parts Manufacturing
This technology enables rapid, customized part production based on individual needs.
In the medical field, 3D printing technology is used for the customization of medical implants and prostheses.
Technicians obtain 3D bone data via CT scan and create a matching, adjustable prosthetic limb.
High prosthesis compatibility helps surgeons succeed, speeds recovery, and improves patient comfort and rehabilitation.
3D printing technology is also widely used in the dental field.
3D scanning obtains accurate mouth data to create customized models and dental appliances, improving treatment and comfort.
Traditional appliances need multiple fittings, but 3D printing molds them in one pass, reducing visits and wait time.
In the field of automotive manufacturing, 3D printing technology can also be used to produce personalized auto parts.
For example, different tracks, drivers have different needs, racing parts generation requirements are also different.
This technology quickly manufactures parts to meet specific needs, improving car performance and safety.
Mold manufacturing and repair
In mechanical design, the manufacturing and repair of molds are crucial, with emerging technologies bringing new opportunities and methods.
Mold Manufacturing
The first step in mold manufacturing is design and modeling.
Designers use CAD software to create 3D mold models considering shape, size, material, and production process.
CAD software allows for detailed structural analysis and optimization of the design to ensure the functionality and durability of the mold.
After the design is completed, the slicing software is used to slice the mold, generate the print path, and output the G code file.
Select suitable printing materials and print mold parts using the 3D printer.
After printing, the parts are assembled to form a complete mold.
During the assembly process, we need to ensure the assembly precision of each part.
After assembly, debug the mold and test it to ensure stable production of qualified products.
Mold repair
Surface repair. During the use of the mold, the surface may have wear, scratches and other problems.
Stacking metal layers on damaged parts quickly repairs surface defects, restoring mold shape and function.
Structural repair. For mold damage like cracks, 3D scanning captures detailed 3D data of the damaged area.
Accurately locate the position and size of cracks and defects through scanning.
Create a 3D model from scan data and reinforce it to ensure the repaired mold withstands production loads.
Using SLM technology, metal powder is built up layer by layer to accurately repair the damaged area and form a strong repair structure.
After repair, perform heat treatment, polishing, and machining to restore the repaired area’s properties and surface quality.
Surface treatment. After repair, the mold usually needs surface treatment to enhance properties and quality.
Common surface treatment methods include spraying, plating and heat treatment.
Through surface treatment, the hardness and wear resistance of the mold surface can be improved to extend the service life of the mold.
Rapid Prototyping
This technology speeds up prototyping and verification, shortening development cycles and boosting R&D efficiency.
Traditional mechanical design requires multiple trials and modifications, making it time-consuming and labor-intensive.
This technology quickly creates prototypes from digital models, speeding development and cutting design costs and time.
The prototypes generated by 3D printing technology can be functionally tested to ensure the feasibility of the design.
This rapid iteration allows designers to identify and solve design problems in a timely manner and improve product quality.
This technology manufactures complex gear prototypes, enabling quick design variations, mesh testing, strength verification, and design optimization.
Engineers quickly prototype and test hydraulic pumps, optimize performance, customize designs, and enhance equipment quality.
3D printing and CNC technology integration
Integrating 3D printing with CNC technology has transformed mechanical design and manufacturing.
Additive manufacturing uses laser sintering and fused deposition; CNC handles milling and turning, broadening material options.
Combining 3D printing and CNC enables complete prototyping to final production on one machine, ensuring precise, complex designs with smooth surfaces.
3D printing quickly creates complex parts layer by layer, while CNC ensures precise tolerances via cutting.
3D printing and CNC technology fuse to process metals, plastics, and composites, especially complex parts with intricate features.
Combining printing and CNC by adding then subtracting materials reduces waste, improves utilization, and saves costs.
Take aero-engine fuel nozzles as an example to illustrate the process.
Create a CAD 3D model and optimize topology to ensure optimal performance with minimal material.
Selective laser melting (SLM) melts metal powder layer by layer with a laser to form the fuel nozzle’s rough shape.
After printing, CNC technology precision machines blanks to meet tight tolerances and surface roughness.
CNC machining steps include removal of excess material, fine grinding, and surface treatment.
Lightweight design
Lightweight design reduces product weight while ensuring strength and performance in modern engineering.
3D printing enables lightweight design, enhancing mechanical performance and transforming manufacturing.
Designers use 3D printing in lightweight design through lightweight materials, structural optimization, and multi-material integration.
Lightweight materials like aluminum, titanium, magnesium alloys, and carbon fiber composites offer high strength and corrosion resistance.
Structures like hollow sandwich, thin-walled reinforcement, dot matrix, integration, and topology optimization can reduce weight.
Combining different materials, 3D printing technology can create composite parts with a wide range of properties.
For example, Airbus used 3D printing to create a cabin support for its A320 aircraft.
The bracket uses high-strength, low-density titanium alloy to reduce weight while maintaining structural strength.
CAD and CAE software optimize the wing bracket’s topology during design.
Designing hollow and reinforced structures minimizes materials while improving strength and performance.
The 3D printing process embeds carbon fiber in titanium alloy to enhance part strength and rigidity while keeping it lightweight and durable.
These design and manufacturing methods cut the weight of Airbus A320’s 3D-printed titanium cabin mounts by 40%.
Material Innovation
3D printing handles metals, plastics, ceramics, and composites, promoting innovation in mechanical materials.
Supports multi-material printing and integration, enabling parts with varied functions.
Combines high-strength and lightweight materials with precise distribution control to manufacture gradient composite parts.
Using heat-resistant materials outside and lightweight materials inside improves overall part performance.
In addition, 3D printing technology can promote the manufacture and application of smart materials.
Shape memory alloys are a typical smart material that can return to a preset shape at a specific temperature.
3D printing manufactures complex shape memory alloy parts for aerospace, medical, and more.
Conclusion
3D printing enables fast, complex, and custom mechanical manufacturing.
3D printing excels in mold repair and rapid prototyping, boosting efficiency, shortening development, and expanding designers’ creative space.
In particular, the integration of 3D printing and CNC technology further improves manufacturing precision and flexibility.
Lightweight design with 3D printing reduces weight and enhances performance through light materials and optimized structures.
These innovations meet modern manufacturing’s demand for efficient, flexible, and personalized production, expanding future design possibilities.