Report Producer:Huafu**
The following is an excerpt from the original report.
1. The basic technology is mature, and new technologies are constantly emerging.
1.1 The seven basic additive technologies are mature and promote the development of the industry.
The ISO ASTM 52900:2015 standard issued by the Technical Committee on Additive Manufacturing of the International Organization for Standardization divides additive technologies into 7 categories, namely: stereolithography (SLA), binder jetting (3DP), directed energy deposition (DED), thin material stacking (LOM), material extrusion (FDM), material jetting (PloyJet), powder bed fusion (SLM, SLS, EBM). At present, the mainstream 3D printing technology can be roughly divided into two categories, namely metal and non-metal. FDM is widely used in the production of finished prototypes or R&D models due to its advantages of easy operation, high material utilization, and excellent mechanical properties of FDM cables. Among the light-curing technologies, SLA technology is the earliest fast-forming technology, which is more suitable for making items with high precision by virtue of the principle of laser scanning and light-curing, but the printing speed is slower in dots. For metals, SLM technology is the most mature, using lasers to superimpose powders layer by layer.
SLM, SLS, and EBM are the mainstream molding processes. SLS and SLM use lasers to stack powders layer by layer, while EBM uses high-energy electron beams to scan molten powder and solidify layer by layer. Compared with SLM, SLS requires the addition of adhesive materials, and the hardness and accuracy of the finished product printed by SLS after mixing powder are slightly worse than those of SLM products.
The heat and energy generated by EBM using electron beam are higher than those of SLM, and it is more suitable for manufacturing high thermal conductivity metals, high-temperature alloys, and high melting point metal parts, but the mechanical properties and product strength of SLM products printed by laser are still slightly better than those of EBM products. On the whole, sintering bonding molding technology can ensure the hardness and good mechanical properties of products by virtue of metal materials and technical characteristics, and is more widely used in industrial manufacturing, aerospace and automobile manufacturing.
1.2 Comparison of metal 3D printing technology: SLM technology has become the current mainstream technology.
The mainstream metal 3D printing technologies are: SLM, EBM, and DED.
a) Selective Laser Melting (SLM).
Selective laser melting (SLM) is the direct thermal action of metal powder through the laser, without relying on binder powder, the metal powder through melting and solidification to achieve the effect of metallurgical bonding, and finally obtain the metal parts of the designed structure. In order to better melt metals, SLM technology requires the use of laser beams with high metal absorption, so ND-YAG lasers are generally used (1064 microns) and fiber lasers (109 microns) and other laser beams with a short wavelength. The advantage is that the SLM technology uses pure metal powders, and the density of the formed metal parts can reach close to 100%;The mechanical properties such as tensile strength are better than those of castings, and can even reach the level of forgingsThe mechanical properties of density and molding accuracy are better.
2) Selective electron beam melting technology (EBM).
Selective Electron Beam Melting (EBM) is similar to SLM technology, except that the electron beam is used as the energy source to selectively melt the metal powder, so that the metal powder melts and solidifies, and the forming method is similar to that of laser selective melting. EBM technology has higher energy utilization rate and forming efficiency, which is conducive to forming brittle materials and crackable materials, but increasing the acceleration voltage will more likely lead to high-voltage discharge of electron guns, so the requirements for equipment and vacuum environment are higher.
iii) Directed Energy Deposition (DED
Directed Energy Deposition (DED) works similarly to SLM in that it uses a high energy source, such as a laser or electron beam, to melt and fuse metal powders together to build parts layer by layer. This technique can add material directly to the part according to the design requirements, resulting in highly complex shapes and structures. The advantages over SLM technology are, first, that it allows the laser head and workpiece to move more flexibly, thus increasing design freedom. Second, in the operation of the DED equipment, the inert gas flows directly from the laser head and envelops the powder stream and melt pool, and does not rely on a pressure chamber filled with inert gas, so the 3D printing process can start immediately, greatly reducing the production preparation time. Third, it can produce large parts without any support structure. The disadvantage is that the melting process is not as precise as SLM, and the finished part often has to be reworked.
Comparison with EBM: EBM printing technology differs from SLM technology in terms of heat source, molding working environment, working molding preheating temperature, powder spreading thickness, and powder particle size. EBM technology is capable of handling high-temperature, crack-prone and reflective alloys with high part density, uniform microstructure, superior mechanical properties and low powder loss. However, there are also significant disadvantages of EBM technology, such as limited print volume, strict requirements for vacuum environment, and more expensive machines and materials.
The selection principles for additive manufacturing are mainly influenced by the application, product quality requirements, materials, molding efficiency, cost, laser, and external environment.
Powders have the greatest impact, and different 3D printing technologies are suitable for different printing materials. From a material point of view: stereolithography (SLA) uses liquid photosensitive resin materials;The layered solid manufacturing method (LOM) requires sheet materials such as paper and plastic film, while selective laser sintering (SLS) and selective laser melting (SLM) mainly use metal and ceramic powder materials.
SLM is the current mainstream solution for metal printing, and the product is relatively cost-effective. Choosing which metal technology to use needs to consider factors such as part detail, shape, size, strength, metal type, cost, print speed, and quantity. The products printed by metal 3D generally have excellent performance, which can meet the demanding performance requirements of aerospace & military, medical and other industries, but also face the problems of high overall printing cost (ranging from tens of thousands to hundreds of thousands), limited size of finished products, and slow production efficiency. Among them, SLM printing is relatively cost-effective, with the advantages of high density, high strength, high precision, and high utilization, while the cost is lower than that of EBM and Lens, and the technology is mature, which is the mainstream solution for metal 3D printing.
1.3. New technologies are constantly emerging, and there is a gap in process innovation at home and abroad.
In recent years, there have been few major innovations in 3D printing technology products in China, and they are usually the improvement and upgrading of old technologiesHowever, new 3D printing technologies and products are constantly emerging abroad, which is very worthy of our consideration. Below, we take stock of the 20 3D printing technology products that are missing in these countries, hoping to attract attention.
2 New technologies emerge one after another, focusing on binder jetting technology and area printing technology.
2.1 SLM technology: mainstream process, comprehensive performance to meet the needs of aerospace and consumer electronics.
Direct metal forming was one of the first metal printing processes to be used, consisting of a uniform layer of metal powder distributed on a print bed. The thickness of the metal powder layer is between 15 and 100 microns. The energy beam scans and melts the powder at the top layer. Currently, L-PBF is the most prevalent industrial solution, using a laser as an energy source. SLM equipment is generally composed of several parts: optical path unit, mechanical unit, control unit, process software and protective gas seal unit
1) Optical path unit: mainly includes fiber laser, beam expander, reflector, scanning galvanometer and f-focusing lens, etc. The laser is the most central component of the SLM equipment and directly determines the molding quality of the entire equipment. The fiber lasers used in SLM equipment have obvious advantages such as high conversion efficiency, reliable performance, long life, and beam mode close to the fundamental mode. High-quality laser beams can be concentrated into very fine beams with short output wavelengths.
2) Beam expander: The function is to expand the beam diameter, reduce the beam divergence angle, and reduce the energy loss.
3) Scanner: Driven by a computer-controlled motor, the laser spot is precisely positioned at any position on the processing surface. Specialized planar f-scan lenses are often used to avoid distortion of the galvanometer scanner unit and to achieve consistent focusing characteristics of the focused spot over the scanning range.
4) Mechanical unit: mainly including powder spreading device, forming cylinder, powder cylinder, forming chamber sealing equipment, etc. Powder spreading quality is the key factor affecting the molding quality of SLM, and there are two main types of powder spreading devices in SLM equipment: powder spreading brush and powder spreading roller. The forming cylinder and powder cylinder are controlled by a motor, and the accuracy of the motor control also determines the forming accuracy of the SLM.
5) Control system: including laser beam scanning control and equipment control system. Laser beam scanning control is a computer that sends a control signal to the galvanometer scanner through a control card to control the movement of the X-Y scan mirror to achieve laser scanning.
There are 9 main processes in the SLM process. The main processes cover data processing, model slicing, raw material loading, printing, depowdering, stress relief, support removal, support surface treatment, and improving assembly surface accuracy.
Inheriting the EOS equipment system, the SLM process is verified by the downstream market. BLT is the 3D printing equipment of EOS in Germany, which was founded in 1989 and is the world's largest provider of metal 3D printing equipment. With the continuous application of EOS equipment in the domestic market, the SLM process is recognized by the downstream market. At present, the main advantages of the SLM process market are: 1) mature software and mechanical technology;2) Process direct delivery of metal parts;3) It has the highest density among all metal additive technologies4) Highly regarded for its ability to print large, heavy-duty end-use parts commonly used in the aerospace industry. However, there are still some disadvantages of this process: 1) workflow and process development require a lot of resources and professionals;2) Thermal stress leads to a decrease in the yield rate;3) The parts are welded to the build plate and must be removed by electric spark, and the support material must also be cut or milled;4) Loose metal powders can be dangerous and require a lot of training to handle. Changing materials takes hours and is a high risk of contamination and **.
2.2 BJAM technology: The cost is lower than PBF and DED technology, and the core performance does not meet the downstream needs.
Binder Jetting Additive Manufacturing (BJAM) technology is a common, low-cost metal 3D printing technology. This technology is based on the powder bed process, through the inkjet print head layer by layer spray binder selective deposition on the powder bed, bonding and printing three-dimensional solid parts blank, and then the printed blank is placed in a uniform thermal environment for debinding and sintering, densifying it and obtaining parts with good mechanical properties.
The application fields represented by industry, electronics, and medical have a broad space, accelerating the development of metal 3D printing technology.
BJAM technology provides an economical way to print metal parts with overhangs, complex internal features, and no residual stresses, with a wide range of applications across multiple industries. For example, in the medical field, BJAM can be used to print denture frames, surgical implants, etc. The printed one-piece composite mesh parabolic reflector antenna significantly reduces the failure rate due to its overall structure. In addition, it also has outstanding advantages of low cost and high efficiency in printing industrial products and artworks such as mesh lightweight and hollow.
As Bjam's technology has evolved, so has its equipment. There are currently 3 main categories of companies that manufacture BJAM equipment: (1) EX ONE (acquired by Desktop Metal). It has a variety of BJAM printers, among which the X1 160Pro device is the largest metal BMAM printing machine at present, and the volume of the forming cylinder is 2 of similar systems5 times more;(2) Digital Metal, in which the maximum reading rate of DM P2500T machine reaches 12 000 cm3 h, and the printing speed is 100 times that of laser selective combustion (SLM) technology(3) Bjam printers have also been introduced by companies such as Desktop Metal, GE, 3DEO, Hewletpackardp (HPD Systems, Voxeljet, etc.), and Ex One has conducted extensive material testing, including 304L, 316L, M2 tool steel, and NI 718 alloy, among others, and other materials include 17-4PH alloy, 6061 aluminum, drill chrome alloy, copper, H13, titanium, tungsten alloy, etc.
The key to BJAM printing technology: materials and binders. 1) Powder properties affect the performance of BJAM prints.
Powder properties mainly include geometric properties such as powder morphology, average size, and particle size distribution, as well as physical properties such as powder fluidity, spreadability, and bulk density. Among them, the morphology and dimensional characteristics of the powder affect the mechanical properties of the part, and the fluidity and bulk density affect the degree of densification of the part. The particle size and particle size distribution affect the density of the blank, which in turn affects the density of the sintered sample and the microstructure of the final part. Powder bulk density is an important parameter to determine the particle arrangement law, and it is also a key parameter that affects the sintering density and shrinkage degree of the final product. 2) Types and characteristics of binders. The binder must be printable, and only if the binder has the right viscosity is guaranteed to form a single droplet and come off the nozzle of the printhead. At the same time, the binder needs to have sufficient bond strength to ensure the integrity of the printed primary blank structure. Binders also affect debinding temperature, sintering temperature, and residue properties.
Compared to PBF and DED technologies, BJAM technology has unique advantages: low cost, wide range of material systems, good surface quality and no support structure. BJAM has a low machine cost because it does not require lasers and precision optics. In addition, the wide range of materials available for BJAM technology is more capable of handling metal materials with high optical reflectivity, high thermal conductivity, and low thermal stability than PBF and DED technologies, although BJAM technology requires depowdering like other powder-based AM technologies, but does not require the addition of support structures and can achieve complex geometries such as cavities.
Metal BJAM technology also has obvious shortcomings, the most important is that it is difficult to obtain high-density parts by post-processing sintering or impregnation, compared with electron beam AM metal parts, the metal parts manufactured by BMAM technology have slightly lower mechanical properties, and can only reach the casting level, and the density and porosity are far from the SLM process, which is difficult to use in the field of consumer electronics.
However, consumer electronics have high requirements for porosity and density due to the need for waterproof and other functions, and the density of the BJAM process for titanium alloy is only 70% according to the previous article, which cannot meet the needs of the downstream market with the current level of process technology, which is a difficulty in the development of the process. In addition, green billets made with BJ are very fragile before sintering, which requires a post-processing step and, in some cases, additional equipment.
2.3-zone 3D printing technology: new ideas for efficiency improvement, potential processes for large-scale production.
The focus of area printing technology is on the design and control of the optical path. The entire system consists of a set of diode lasers, an incoherent beam combination optical system, a short-pulse laser and transmission optics, an optically addressable optical valve (OALV), an image projector, and other optics above the print plane. Area printing uses a modular pulsed infrared laser source with a maximum output power of 30 kW. How it works can be broken down into four steps:
1) The beam of the pulsed infrared laser source is shaped to convert the output into a uniform, consistent square field, approximately 15x15 mm.
2) The blue laser projector projects the cross-sectional pattern of the part onto the square area of the infrared laser beam. The blue light pattern represents the part geometry within each square field. The entire square area contains more than 2.3 million pixels, each measuring 6-10 microns, which is higher resolution than the existing PBF-LB process in the X and Y directions, with each layer fixed at 25 microns.
3) The adjusted infrared and blue light pass through an optically addressable light valve. An optically addressable photovalve changes the amplitude or intensity, phase, polarization state, and wavelength of the incident light distribution under the control of an optical or electrical signal.
In the area where the two beams of light coincide, the infrared light field will appear in a horizontal direction;In areas where there is only infrared light, the infrared light will appear vertical. This is a critical step in achieving selective directing of infrared light onto the powder bed, melting the powder in a predetermined pattern.
4) Under the action of the polarizer, the infrared light in the horizontal and vertical states is separated. A patterned beam of light is used to melt the powder. The remaining infrared light is sent to the beam collector. The entire process is repeated forty times per second, that is, the powder is melted into forty square areas in one second.
End of excerpt from the report For more information, please read the original report
List of topics in the report collection x Regularly compiled and updated by [Report School].
(Special note: This article ** is public information, the excerpt is for reference only, does not constitute any investment advice, if you need to use, please refer to the original report.) ）
Technology, Electronics, Semiconductors
Artificial Intelligence |AI Industry |AI Chip |Smart Home |Smart Speaker |Intelligent Voice |Smart Home Appliances |Smart Lighting |Smart Toilet |Smart Terminal |Smart Door Locks |Smartphone |Wearables |Semiconductors |Chip Industry |3rd Generation Semiconductors |Bluetooth |Wafer |Power Semiconductors | 5g |GA RF | igbt | sic ga | sic gan |Discrete |Compound |Wafer |Packaging & Testing |Display | led | oled |LED package |LED Chip |LED Lighting |Flexible folding screen |Electronic components |Optoelectronics |Consumer Electronics |Electronic FPC |Board |Integrated Circuits |Metaverse |Blockchain |NFT Digital Collection |Virtual Currency |Bitcoin |Digital Currency |Asset Management |Insurance Industry |InsurTech |Property & Casualty Insurance |