The additive manufacturing (3D printing) process of metal materials is in great demand in the fields of aviation, aerospace, navigation, vehicles, mold manufacturing, medical equipment, etc. At present, the heat sources used in the metal additive manufacturing process include three high-energy beams, namely laser beam, electron beam, and micro-beam plasma, as well as sintering heat input. Among them, the laser beam is the most widely used high-energy beam heat source in the field of metal additive manufacturing. Compared with electron beam and micro-beam plasma heat sources, the laser beam has the advantages of fine spot, low cost, and can be directed to the specified material position. It can achieve instant melting of metal materials and meet the requirements of melt channel overlap and part forming.
Basic principles of laser 3D printing
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The lasers used in laser 3D printing include fiber lasers, semiconductor lasers, Nd:YAG lasers, and CO2 lasers. Different materials absorb lasers of different wavelengths differently. Usually, CO2 lasers are used to print polymers, while fiber lasers are used to print metal powders.
According to different processing methods, laser additive manufacturing can be divided into selective laser sintering, selective laser melting, direct metal laser sintering, laser powder deposition, direct metal deposition, etc. Among them, selective laser melting (SLM) is one of the most widely used metal laser 3D printing technologies.
The basic structure of the selective laser melting (SLM) printing device is shown in the figure. Before printing, the 3D model must be layered and then the scanning trajectory must be determined. The first step is to evenly scrape the workbench with a scraper and spread a layer of powder on it; the second step is to scan a specific trajectory on this layer of powder with a laser to melt it and print a layer; the third step is to move the workbench down one layer, and then repeat the above operation to stack the printing layers from bottom to top, thus forming the 3D part to be printed. In order to prevent oxidation, the working chamber must be evacuated and filled with inert gas during the entire process.
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The demand for lasers in laser 3D printingThe demand for lasers in laser 3D printing is mainly reflected in two aspects: on the one hand, power and power stability, and on the other hand, beam quality and spot size.
01 Power and power stability
The 3D printing process mainly relies on the thermal effect of the laser. The laser intensity must exceed a certain energy threshold to melt the material. Therefore, it pays more attention to the average output power of the laser and is not sensitive to the pulse mode of the laser. Therefore, continuous fiber lasers are usually used, and the power is roughly distributed between 100W and 1000W.The larger the model and the more layers, the longer the printing time. The duration is generally from a few hours to dozens of hours. Therefore, high requirements are placed on the long-term stable operation of the laser. If the temperature is too high, the metal powder may be overburned and even cause other formed parts to remelt; if the temperature is too low, the metal powder is not completely melted, the bonding force is insufficient, and the shape of the formed component may not be maintained. Therefore, the power stability of the laser is crucial to the printing quality.
02 Beam quality and spot size
Beam quality and spot size are one of the key parameters that reflect printing accuracy. 3D printing is formed by laser beam scanning. The smaller the laser spot, the higher the scanning accuracy, the higher the resolution of the printed model, and the more delicate the surface of the printed part is.Beam quality is usually characterized by BPP or M2. The closer M2 is to 1, the better the beam quality, the more concentrated the laser energy, and the smaller the heat effect on the surrounding area; at the same time, the better the beam quality, the smaller the corresponding divergence angle, and the smaller the focused spot will be.
03 GW Laser Tech and FASTFORM's exploration in the field of 3D printingGW Laser Tech, as the world's leader in high-brightness fiber lasers, has also actively explored this application field with the rise of 3D printing technology, and launched a 500W single-mode 10μm/14μm continuous fiber laser for 3D printing applications, targeting medical devices, automotive parts, aerospace and other fields.
Among them, the different core diameters of 10μm and 14μm determine the spot size, which mainly affects the laser power density, that is, the amount of light energy per unit area. Under the same power conditions, the smaller the spot size, the greater the laser power density. High-power density spots are suitable for printing metal powders with high melting points or high reflections.
Product advantages:
• Ultra-thin and lightweight design, 19-inch 1.5U height design, weight <20kg, compact structure, small size, light weight, giving unparalleled integration convenience and flexible versatility.
• The product structure adopts a closed design, aimed at the 3D printing environment, greatly improving the overall reliability of the laser, IP65 protection level, and can operate continuously in harsh environments such as high temperature, high humidity, and high dust.
• The maximum power is 500W, which is enough to form common metal materials such as austenitic stainless steel, martensitic stainless steel, titanium alloy, nickel-based high-temperature alloy, aluminum alloy, magnesium alloy, etc.
• Good power stability, fluctuation per hour <0.5%, ensuring process consistency for ultra-long printing.
• Good beam quality, M2<1.1, single-mode 10/14μm fiber output, small output spot, and high printing accuracy.
FASTFORM (FastForm) is a company specializing in the research and development of 3D printing technology and equipment, and can provide top rapid prototyping services and supporting solutions. We have established in-depth cooperation with Guanghui Laser, and will conduct 3D printing experiments and research on key parts in the fields of aerospace, automobile models, biomedicine, etc. in the future. We have launched FF-M140 single laser products, FF-M150 teaching-specific models, FF-M180D dual laser dental-specific models, FF-M300H 1000W high-power laser industrial models, FF-M500 dual laser models, and FF-M800 four laser products, and all of them have been mass-produced and support customized localization solutions. We independently developed FastLayer, a multi-laser slicing and path generation software. The equipment is fully automatic and unattended.
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This product has the following significant advantages:
• Bidirectional and variable speed powder spreading technology, high powder utilization rate.
• Independently developed software to complete automatic slicing and path planning with one click.
• Comes with its own camera, which can realize fully automatic control and unattended operation remotely.
• The equipment adopts an integrated welding structure, which is highly stable and easy to install.
Current status and development prospects of 3D printing industryAt present, 3D printing has entered the era of rapid prototyping. According to statistics from the China Business Industry Research Institute, the machinery industry accounts for the largest proportion of downstream application fields in 2021, reaching 17.5%, followed by consumer electronics (16.6%) and automobiles (16.1%). With the rapid development of consumer electronics and the automotive industry, the application areas of 3D printing in these two fields will be further expanded in the future.
In terms of industry scale, according to China Investment Network's forecast: the average annual compound growth rate of 3D printing from 2021 to 2025 will be about 26.59%, and it will reach 70.1 billion yuan in 2025.
3D printing covers three aspects: equipment, materials and services, among which printing equipment accounts for the largest share. According to data released by CCID, the scale of China's 3D printing equipment industry in 2020 was 9.254 billion yuan, accounting for the largest proportion.
At present, the price of 3D printing equipment is still relatively high. On the one hand, it is due to foreign patents and monopolies. On the other hand, it is because my country's 3D industry started late, the demand is small, and the degree of autonomy is low. With the upgrading and development of my country's high-end manufacturing industry, the development of technology and the reduction of costs, my country's 3D printing industry will show a trend of increasing localization in the future. Close cooperation between equipment manufacturers is crucial to promoting the large-scale development of 3D printing technology.
Guanghui Laser not only focuses on the research and innovation of laser product technology, but also continues to explore in the field of laser processing technology, and is committed to helping customers solve application problems. As a leading domestic 3D printing equipment manufacturer, FASTFORM is familiar with all aspects of 3D printing and has an experienced consulting team to provide customers with professional high-end products in the field of 3D printing. In the future, Guanghui Laser will work with FASTFORM to promote the application and development of laser 3D printing technology in China and help upgrade the industry.
Source: Guanghui Laser
Author: Application Engineer Gu Jiaxing
Media Contact
Company Name: FastForm 3D Technology Co., Ltd.
Email: Send Email
Country: China
Website: https://www.3dfastform.com/
