Lattice structure of 3D printing and traditional industry
1. Lattice structure characteristics and energy absorption capacity
1) One of the most important properties of lattice materials is the energy absorption capacity, which is characterized by the ability to absorb or dissipate mechanical energy during compression. It has been confirmed that most lattice structures, such as pyramid lattices, three-dimensional Kagome lattices, tetrahedral lattices, and diamond lattices, can achieve very good energy absorption performance by changing geometric parameters such as aspect ratio or unit cell size.
2) Designable sandwich panels with lattice structures have also been shown to have excellent energy absorption properties. In addition to geometric parameters, the energy absorption performance can also be tuned by complex structures such as gradient structures, metal foam filled structures, multilayer structures, and different unit cell structures, which have been shown to be more efficient in energy absorption than single lattice structures efficient.
3) The method to improve the mechanical properties or energy absorption capacity is to modify the nodal structure connecting the struts. When subjected to compression or shock loads, stress concentration usually occurs. This method is relatively simple, but it can improve the energy absorption capacity of the metal lattice structure
2. Comparison of lattice structure of traditional process and 3D printing
There are several techniques for fabricating metal lattice structures in conventional processes, including stamping, extrusion-bonded wire cutting, expansion sheet folding, and investment casting. In addition to casting, these techniques must use bonding or welding techniques to assemble the struts to form the lattice structure. During processing, junctions are often sensitive to defects, such as bubbles and microcracks, leading to a weakening of the overall mechanical properties of the lattice structure. For investment casting technology, the electrolyzer configuration cannot be too complicated due to the limitations of the technology itself.
Lattice has some unique properties that are very useful when designing parts or products that are almost impossible to replicate with traditional design techniques. Studies have shown that polygrain structures are up to seven times stronger than standard lattice objects in single,a significant strength difference for rearranging certain geometries that only 3D printing can achieve.It was found that no other fabrication method could produce these structures.
3. Why choose 3D printed lattice structures
1) Reduce material usage
Using lattices in a design can greatly reduce the amount of material used by removing most of the material in non-critical areas.
2) Lightweight
Reducing material usage reduces weight. In many applications, the weight of a part or assembly is usually as light as possible. the less material used to create a part equals to a lower price
3) Energy absorption
The lattice structure has many properties that are beneficial for absorbing energy. By varying the density of different regions, and even cell types, the design can efficiently absorb energy in different directions. Complex lattice types can be redirected and better distribute energy in multiple directions to absorb impact forces, while taking advantage of the various properties of modern additive manufacturing resins.
4) Increase the surface area
Some applications focus on maximizing surface area rather than mechanical strength. For example, heat transfer or chemical reactions may be the primary target. Lattice structures are useful here because they give the part more surfaces without increasing its overall footprint.
5) Osseointegration
This refers to a method of creating lattice structures in medical implants to promote bone growth. The resulting implant forms a stronger bond with the patient's own bone structure.
4. Lattice structure type
Lattice are all based on a unit cell. This is a repeating unit that is repeated in multiple directions to form a whole.Lattice types are divided into categories based on their properties
1) TPMS lattice
Triple Period Minimum Surface ( TPMS ) lattices are created when a unit cell is generated using trigonometric equations
2) Strut lattice
A lattice of struts consists of interconnected beams, connected in various patterns defined by the cells. Pillars can be connected by vertices, edges and faces of cube elements, and different combinations of these connection points result in different types.
3) Planar lattice
A planar lattice is the simplest type of lattice and is created when a 2D unit cell is extruded into 3D. The most common type of planar lattice is the honeycomb structure.
3D printing lattice structures is the ideal solution to the problem. It has a precisely engineered lattice structure, virtually unlimited matrix materials, optimized properties, and can be fabricated by many industrial-scale technologies, making them ideal for use in automotive, medical, sports equipment, heat exchangers, consumer products important applications.
