3D printing——
High-end manufacturing weapon (open book and know new)
People's Daily by Lu Bingheng (20th edition on April 19, 2022)
3D printing is a popular technology in the manufacturing industry with a wide range of applications.
It can print not only non-metallic materials such as plastics and ceramics, but also metal materials such as steel, aluminum alloys, titanium alloys, and high-temperature alloys, as well as composite materials, biological materials and even living materials. The forming size ranges from micro-nano components to 10 meters. The above large-scale aviation structural parts provide a huge opportunity for the development of modern manufacturing and the upgrading and transformation of traditional manufacturing.
Compared with traditional manufacturing methods, 3D printing is very different in concept.
The products we often use are all three-dimensional, and the traditional manufacturing methods are mold forming or cutting, also known as isomaterial manufacturing and subtractive manufacturing.
Equal material manufacturing is known as casting, forging and welding, which has a history of thousands of years.
Whether it is Sanxingdui in Sichuan, or the Terracotta Warriors in Shaanxi, you can see exquisite bronzes made of equal materials.
After the advent of the electric motor, it can be used as a power to cut materials.
Because material is gradually cut away during the turning, milling, and milling process, it is called subtractive manufacturing.
Compared with the above two traditional manufacturing methods, what we commonly call 3D printing technology is a new manufacturing method invented in the 1980s. Additive Manufacturing.
Although in concept, the swallows holding mud and the Great Wall can be regarded as additive manufacturing, but only under the control of the computer, the required materials are accumulated to the required places according to the design, and the controllability of the shape can be realized. material manufacturing.
Enabling product design and manufacturing to promote high-end manufacturing
After years of research and development, people have invented 3D printing technologies such as light curing, powder sintering, and wire accumulation.
These three technologies respectively use laser scanning on the surface of liquid photosensitive resin to make it solidify, or high-energy beam scans material powder to sinter it, or uses heat/arc/high-energy beam melting wire to lay it according to the graphic section, etc., on the section The layers are accumulated to form three-dimensional solid parts.
With the rapid development of information technology, 3D printing technology can print a variety of materials and arbitrary shapes under the control of computers. Therefore, many major changes are being brought about in industry and daily life.
Different manufacturing technologies have different technical characteristics.
For example, the casting, forging and welding process made of equal materials requires molds and sand molds. If we only make one sample, the cost will not be worth it. It is more suitable for mass production.
Of course, subtractive manufacturing can also be used for machining, but the machining process results in material waste.
For example, in aerospace manufacturing, in order to achieve light weight, some parts are large but very light and have complex shapes. To distribute the material as much as possible on the edge, it is necessary to cut off a lot of material.
For some precious metals such as aluminum alloys and titanium alloys, the cost is high.
3D printing technology gets rid of production preparation work such as molds and fixtures, and greatly shortens the cycle and reduces costs in new product development, first-piece manufacturing, etc.
And through computer control, digitalization is fully realized. Wherever materials are needed, they can be deposited where they are, so as to achieve material saving manufacturing.
At present, many Chinese enterprises have strong manufacturing capabilities, but their product development capabilities are relatively insufficient, which restricts the development of the manufacturing industry to the top of the value chain.
3D printing can help us make up for this shortcoming and shorten the process of design iteration, prototyping, evaluation, analysis, improvement, and mass production.
For example, in the rapid development and iterative upgrade of high-end equipment such as aerospace, 3D printing has become a powerful tool for new product development.
3D printing also opens up huge space for innovative designs.
In the past, although designers had good ideas, due to the complexity of mold manufacturing and the accessibility of cutting space, they could not design according to the original ideas. They could only disassemble large parts into dozens or hundreds of small parts. The cost of design and manufacture increases accordingly.
For part shapes or structures that are difficult to achieve in traditional manufacturing, 3D printing can be competent, and through structural integration manufacturing, the optimal design concept can be achieved.
This provides huge space for design innovation, product innovation, and equipment innovation, thereby bringing immeasurable benefits to the manufacturing industry.
For example, a large company that produces aircraft engines originally needed to divide the nozzles into more than 20 parts to manufacture due to the limitations of manufacturing technology in the process of manufacturing engine fuel nozzles.
Each of these 20-odd parts has to be on the micron scale and needs to be welded together when assembled, but once welded, the micron-scale accuracy is not achieved.
As a result, there is a lack of consistency in the manufacture of fuel nozzles and fuel efficiency is difficult to optimize.
Now, more than 20 parts can be 3D printed in one piece, simplifying the complexity, improving the fuel efficiency of the parts, and greatly enhancing the competitiveness of the product.
In addition to being good at designing and manufacturing complex parts, 3D printing can also play a role in personalized manufacturing.
With the process of informatization, personalized manufacturing is replacing assembly-line mass manufacturing in more and more fields.
Consumer goods such as home appliances, wearable electronic devices and even automobiles are becoming more and more personalized, and 3D printing is particularly good at personalized manufacturing.
For example, 3D printing a pair of shoes for an athlete that best fits their foot shape will help improve the wearing experience and improve athletic performance.
In the field of precision medicine, such as orthopedic surgical aids, orthodontics, surgical models, etc., more and more applications of 3D printing can be seen.
New products of 3D printing medical devices are emerging in an endless stream. They have been initially used to manufacture bioprostheses, and have expanded to research on cell, tissue and organ printing. In the future, they may be used to recreate human organs and bring benefits to human beings.
The industrial chain continues to expand, and "3D printing +" has reached a new level
The global additive manufacturing industry chain is constantly expanding.
Enterprises and service providers in the fields of aerospace, navigation, energy and power, automobile and rail transportation, electronics industry, mold manufacturing, medical health, digital creativity, construction, etc. are constantly pouring into the additive manufacturing industry.
The automotive industry has surpassed aerospace, medical and other fields to become the largest application industry of 3D printing technology, including prototyping, mold manufacturing and batch 3D printing parts.
3D printing is also playing an increasingly important role in cutting-edge scientific research.
3D printing technology can quickly mix different materials together under controllable conditions to print test pieces or parts. Therefore, according to the material genome method, new alloys and new composite materials can be experimented and invented to rapidly develop more and more innovative materials for industrial applications. Good new materials meet the various needs of high-end equipment and new products.
In recent years, functionally graded materials have received more and more attention.
Print parts with a variety of different materials, layer the materials, and print different materials on different layers, the parts can achieve wear-resistant and corrosion-resistant surfaces, high strength and good toughness inside, and the inside is like the bones of the human body , is a loose honeycomb structure.
As a result, the product reduces weight while increasing rigidity.
At present, people are working on the development and industrialization of additive manufacturing technology.
3D printing has been used in my country's aerospace development and small batch manufacturing, rapid development and lightweight of automobiles, precision medicine, cultural creativity and other fields.
In terms of material preparation, mainstream 3D printing technology and equipment, key components, control software and engineering applications in various fields, an innovation chain and industrial chain have been initially formed.
Last year, the scale growth rate of my country's additive manufacturing industry was higher than the global growth rate over the same period.
my country has applied 3D printing to high-load bearing parts such as aircraft landing gear; many 3D printed parts have been installed on the launch vehicle engine of China's first Mars probe "Tianwen-1".
As a short-process manufacturing technology, 3D printing has also played a role in the fight against the new crown pneumonia epidemic, such as 3D printing medical shelters, goggles, breathing valves, etc.
After nearly 40 years of development, additive manufacturing has entered the "3D printing+" stage.
It has gradually developed from prototype manufacturing to direct manufacturing and batch manufacturing; from model mold manufacturing with shape control as the main goal, to component component manufacturing with both form and function integration; from micro- and nano-scale functional components manufacturing Printing civil buildings up to tens of meters in size... As a transformative technology, additive manufacturing is a powerful tool for advanced manufacturing and an integral and important part of intelligent manufacturing.
With the in-depth development of "3D printing +", additive manufacturing, subtractive manufacturing and other material manufacturing will move towards mutual integration.
Different manufacturing technologies have their own strengths, and play a joint effort to jointly promote my country's progress from a manufacturing power to a manufacturing power.
(The author is an academician of the Chinese Academy of Engineering and a professor of Xi'an Jiaotong University)