Contributors: Yang Fan, Gao Lin
Supplier: State Key Laboratory of Mechanical Manufacturing System Engineering
Metals and polymers are the most commonly used materials in the engineering and medical industries, and their hybrid structures are commonly used in cars, airplanes, electronics and medical implants.However, the traditional mechanical fastening, bonding, welding and other processing methods have certain limitations, such as long assembly time, high cost, low flexibility of geometric design.3D printing can solve this problem by adding materials layer by layer to produce customized metal/polymer components with complex geometric shapes.
Fuse manufacturing technology (FFF) can be used for 3D printing of metals, and laser powder bed melting technology (PBF) can be used for 3D printing of polymers.Researchers from the University of Manchester in the United Kingdom combined these two technologies and introduced a specially designed mechanism and operation procedure to propose a hybrid multi-material 3D printing system. Its structure is shown in Figure 1, and the operation process of the system is shown in Figure 2.The metal materials used in the study are 316L stainless steel atomized spherical powder and Cu10Sn copper alloy spherical powder, the bottom material is 304 steel cylinder plate and block, and the polymer material is polylactic acid (PLA) and polyethylene terephelate (PET) filament.
Using this integrated system, the researchers successfully printed complex 2d and 3D geometric elements made of metal and polymer, and used laser cladding and remelting to locally control and process the rough surface of the polymer.Scanning electron microscope (SEM) and energy spectrum analysis (EDS) were used to observe the metal/polymer interface and no obvious defects were found, indicating that the polymer penetrates well in both macroscopic and microscopic mechanical structures. Tensile and shear tests also proved the good connection strength of the metal/polymer components.In addition, the researchers are trying to melt metal on polymer substrates with lasers.The results showed that all layers of copper powder were coated on the top of the polymer substrate by laser cladding, and the scanning parameters should be constantly changing, with the first layer requiring lower energy and the subsequent layer requiring higher energy, so as to prevent serious damage to the polymer substrate.
The technology could be used in electronic device manufacturing to print various electronic components through the integration of polymers and conductive materials.In biomedicine, researchers have developed a 3D-printed metal/polymer implant that inserts a biodegradable polymer loaded with antibiotics into a metal implant with controlled drug delivery characteristics for local drug delivery.Similarly, we can also use other material systems, such as metal matrix composites and reinforced polymer composites, for the processing and manufacturing of related products and expand their application scope.
Chueh y-h, Wei C, Zhang X, Li L. Integrated laser based powder bed fusion and fused filament fabrication for three-dimensional printing of hybrid metal/polymer objects. Additive Manufacturing. 2020;31.