Special powder materials near net shape manufacturing technology and application1

1. Project name

High performance special powder materials near net shape manufacturing technology and application

2. Nominators and nomination opinions

Nominator: China Nonferrous Metals Industry Association

Nomination comments:

High-performance special powder materials play an irreplaceable key role in national defense equipment and civilian high-tech products. However, due to problems such as high hardness, high brittleness, and performance sensitivity to processing conditions, it is difficult to prepare usable parts using traditional material processing technology, which greatly limits the performance and effective utilization of this type of material. It has also become the basis for many of my country's national defense equipment. and bottlenecks in the development of civil industry. This project has overcome three major technical bottlenecks: preparation of special powder raw materials, precision forming and control of structural properties. Invented a new technology for the preparation and modification of micro-near spherical special powder, realizing the autonomy of special powder raw materials for injection molding; invented a new binder suitable for different powder material systems and a forming and efficient degreasing process to solve the problem of feeding Problems such as filling properties, shape retention, residual carbon or oxygenation, and dimensional accuracy control; invented the technology for enhanced sintering densification of porous degreased blanks and precise control of microstructure properties, achieving near-net-shape manufacturing and greatly improved performance; invented magnetic field injection molding With key equipment such as machines, high-efficiency degreasing furnaces and energy-saving sintering furnaces, we have established online detection and monitoring software and hardware systems to achieve fully automated production. Applied for 142 invention patents (including 1 PCT patent), including 52 authorized invention patents, 6 software copyrights, published 2 books and 133 papers (including 122 SCI papers), with a variety of products breaking foreign technology blockades and solving It has solved many "stuck neck" problems in the construction and research and development of national defense equipment, met major national needs, led and promoted the formation and development of my country's powder injection molding industry, built 54 production lines, and added sales of 3.95 billion yuan in the past three years. , the new profit was 790 million yuan, and the social and economic benefits were significant.

Won 2 first prizes of the Ministry of Education’s Technology Invention Awards and 2 first prizes of the China Nonferrous Metals Industry Science and Technology Invention Awards.

This project was nominated for the second prize of the National Technology Invention Award.

3. Project Introduction

This project belongs to the powder metallurgy discipline in the field of new materials. High-performance special materials have special properties that other materials do not have and play an irreplaceable key role in national defense and civilian high-tech products. However, this type of material has problems such as high hardness, high brittleness, and sensitivity to processing conditions. It is difficult to prepare usable parts using traditional technology, which greatly limits the performance and effective utilization of this type of material. It has become a popular choice for many national defense equipment and civilian applications. bottleneck in the development of the industrial sector. Powder injection molding has unique advantages in preparing complex-shaped parts from difficult-to-machine materials and is considered one of the top ten disruptive technologies in the future manufacturing industry. However, the technical difficulties faced by this technology are different for different materials, and innovative research needs to be carried out in a targeted manner.

The project lasted for 18 years. In response to the needs of defense equipment, automobiles, wearable electronic products and other fields, research on the injection molding of special powder materials such as metallic tungsten, aluminum nitride, and soft magnetic alloys was carried out, and breakthroughs were made in the preparation of nearly spherical fine powders, Key technologies such as precise forming and microstructure and property control have enabled the near-net-shape manufacturing of such material products. Applied for 142 invention patents (including 1 PCT patent), including 52 authorized invention patents, 68 authorized utility model patents, 6 software copyrights, published 2 books, and published 133 papers (including 122 SCI papers).

1. Created a new technology for the preparation and modification of nearly spherical fine special powder suitable for injection molding process. The reaction system and process for solution combustion synthesis of refractory metal and non-oxide ceramic powder, as well as the new technology of "air flow dispersion classification-plasma spheroidization" powder modification, were established to prepare nano-sized nearly spherical aluminum nitride and tungsten-based powders. The particle size and particle size distribution of spherical tungsten powder are controllable.

2. Invented new binders and forming and efficient degreasing processes suitable for different powder material systems. For the first time, two-phase flow theory and chaos theory were applied to the study of the powder injection molding filling process, clarifying the essential cause of two-phase separation and the uncertainty mechanism of defect generation. A binder system based on polymer functional groups was developed to solve problems such as feed filling uniformity, shape retention, carbon residue or oxygenation, and defect control.

3. Invented the technology for enhanced sintering densification of porous degreased blanks and precise control of tissue properties. In order to solve the problem of difficulty in sintering and densifying the degreased billet, based on the principles of fine-grain strengthened sintering and structure activation sintering, a new strengthened sintering process of metal tungsten and iron-based soft magnetic alloy was established. The maximum magnetic permeability of iron-based soft magnetic alloy was increased by 3- 5 times, the electronic impact resistance of tungsten is improved by 2 orders of magnitude. The synergistic effect of liquid phase sintering and "residual carbon deoxidation" is comprehensively utilized to achieve aluminum nitride densification, grain boundary phase control and lattice purification, with a thermal conductivity as high as 248W·m-1·K-1.

4. Invented key production equipment such as magnetic field injection molding machines, high-efficiency degreasing furnaces and energy-saving sintering furnaces, and established online detection and monitoring of product size and appearance quality based on machine vision, as well as dynamic grabbing, assembly and sorting software and hardware systems for industrial robots. , realize fully automated production, increase production efficiency by more than 6 times, and control the standard sample size accuracy to ±0.2%.

The project technology has passed the achievement appraisal (evaluation) organized by the China Nonferrous Metals Industry Association and the Ministry of Education. The expert group evaluated: "The injection molding process technology of complex-shaped aluminum nitride components has reached the international leading level", "The precision preparation technology of high-performance tungsten metal products" The innovation is outstanding, the application results are obvious, and the overall technology has reached the international leading level." Relevant achievements have won 2 first prizes of the Ministry of Education’s Technology Invention Awards, 2 first prizes of the China Nonferrous Metals Industry Science and Technology Awards (Inventions), and 2 product awards of the World Powder Metallurgy Congress. 54 production lines have been built, among which Harber Industrial and Shanghai Fuchi have developed into the two largest injection molding companies ranking high in the industry. In the past three years, it has increased sales by 3.95 billion yuan and added profits of 790 million yuan. It has also solved a number of "stuck" problems in the development of national defense equipment and achieved significant economic and social benefits.

(2) Conclusion of science and technology novelty search report

According to the novelty search results of the Science and Technology Novelty Search Workstation of the Ministry of Education, among the published documents and patents at home and abroad, except for the documents and invention patents published by members of the novelty search project team and the students they supervised, there are no novelty searches related to this novelty search. The following reports on the same project: developed solution combustion to synthesize nano-tungsten-based powder, and prepared tungsten products with a density greater than 95%, a grain size of approximately 570nm, a hardness of 699HV0.2, and a flexural strength of 568MPa; developed " Airflow dispersion + plasma spheroidization "method to prepare fine-grained, narrow-distributed spherical tungsten powder, and prepare complex-shaped porous tungsten products with uniform pores and good connectivity; a "deoxidation" technology using residual carbon in the binder was developed, And prepared aluminum nitride products with thermal conductivity as high as 248W·m-1·K-1; developed a method to use delta phase sintering to prepare iron-based parts close to full density (>99.9%), with magnetic induction intensity B6000=1.81T, Coercive force Hc=20.6A/m, maximum magnetic permeability μm=21.8mH/m pure iron soft magnet; developed a liquid phase sintering method using P added, which greatly reduces the sintering temperature and shortens the sintering time, μm= 21.4mH/m, B6000=1.77T, Hc=21A/m iron-phosphorus soft magnet; developed a fully dense, Bs=1.58T, Hc= 2.52A/m, μm using HIP and subsequent heat treatment process =112mH/m Fe-50%Ni soft magnetic alloy, and Bs=0.862T, Hc=0.95A/m, μm=210000 Fe-79%Ni-4%Mo soft magnetic alloy reported.

(3) Identification conclusion

On July 20, 2015, commissioned by the Ministry of Education, the University of Science and Technology Beijing organized a scientific and technological achievement evaluation meeting on "Powder Injection Molding Technology for High-Performance Metal Soft Magnetic Materials" in Beijing. The expert group concluded: "This achievement achieves complex shapes. The low-cost near-net-shape manufacturing of high-performance soft magnetic parts has significant innovation and broad market prospects. The overall technology has reached the international advanced level, and the main performance of some injection molded soft magnetic products has reached the best international level."

On May 9, 2017, the China Nonferrous Metals Industry Association organized a scientific and technological achievements evaluation meeting on "High Thermal Conductivity Aluminum Nitride Products Precision Manufacturing Technology" in Beijing. The expert group concluded: "This technology is highly innovative and is an important military and civilian application." Using technology, the overall technology has reached the international advanced level, among which the process technology represented by injection molding of complex-shaped components has reached the international leading level."

On July 18, 2018, the China Nonferrous Metals Industry Association organized a scientific and technological achievement evaluation meeting on "High-Performance Metal Tungsten Products Precision Preparation Technology and Application" in Beijing. The expert group concluded: "Relevant achievements are important in national defense weapons and civilian products." The successful application has made an important contribution to the realization of high performance of weapon systems and the development of related industries, with significant economic and social benefits. The achievement is innovative, the application results are obvious, and the overall technology has reached the international leading level."

(4) Technical test report
The performance of metal tungsten, aluminum nitride, and iron-based metal soft magnetic products has been tested by the National Nonferrous Metals and Electronic Materials Analysis and Testing Center, China Institute of Metrology, and Tsinghua University, and meets the technical index requirements.

(5) User opinions

The new technology for the preparation and modification of nearly spherical fine special powders developed is used in the production of linear motor oscillators for mobile phones. The new technology of powder modification treatment greatly improves the bulk density, tap density and fluidity of the powder. This technology is applied to the preparation of tungsten-based alloy vibrators for mobile phone linear motors. Under the condition of ensuring the rheological properties of the feed, the powder is The loading capacity is increased by 10%, thereby reducing the shrinkage and deformation of the green body during degreasing and sintering, improving the dimensional accuracy of the product and reducing production costs. Related products have been industrialized in Shanghai Fuchi High-Tech Co., Ltd.

The new adhesive and degreasing process developed are used in the preparation of mobile phone camera circles. The polyformaldehyde-based binder and catalytic degreasing technology developed using this achievement have been successfully used in the development and production of mobile phone camera circles, greatly improving the degreasing efficiency of the product, reducing the carbon content, and reducing sintering deformation and melting problems. occurs, ensuring the mechanical properties, corrosion resistance and non-magnetism of the material. Related products have been industrialized in Shenzhen Elite Technology Co., Ltd.

The developed spherical tungsten powder is used in the preparation of diffusion cathode porous tungsten substrate. Chengdu Guoguang Electric Co., Ltd. uses the fine-grained and narrow-distributed spherical tungsten powder developed by this achievement as raw material to prepare a diffused cathode porous tungsten substrate, which achieves precise control of the pore structure and greatly improves pore connectivity and porosity. Compared with porous tungsten substrates prepared from commercially available tungsten powder, the amount of immersed salt (emitting material) increases by about 20% while ensuring porosity, which greatly improves the emission performance and service life of the cathode.

The developed iron-based soft magnetic products are used in moving iron units of speakers or hearing aids. We have developed ED, TEC, SR, PHF and other yoke (YOKE) parts of various specifications for Knowles Electronics in the United States. User evaluation: "Performance and size are stable. , meets the usage requirements”. The developed yoke parts for dot matrix printers have been successfully used in Nanjing Fujitsu Computer Equipment Co., Ltd. and Anhui Ningzhi Technology Co., Ltd.: "The developed yoke parts have good performance, high dimensional accuracy and meet the usage requirements"; "The product has good consistency in size and performance, the size meets the assembly requirements, the needle has strong impact, the work is stable, and the performance is excellent."

(6) Technology awards

1. First Prize of the Ministry of Education’s Technology Invention Award in 2012 - research on trigger detonation switch discharge electrode and its near-final forming technology;

2. First Prize of the Ministry of Education’s Technology Invention Award in 2018 - Precision Preparation Technology and Application of High-Performance Metal Tungsten Products

3. First Prize of the 2016 China Nonferrous Metal Industry Technology Invention Award - High Performance Metal Soft Magnetic Products Near Net Shape Manufacturing Technology;

4. First Prize of the 2017 China Nonferrous Metal Industry Technology Invention Award - High Thermal Conductivity Aluminum Nitride Precision Forming Technology and Application;

5. Application

1. Application

The project has formed a near-net shape manufacturing technology for high-performance special powder materials with my country's completely independent intellectual property rights, including new technologies for special powder preparation and modification, near-net shape and efficient degreasing technology, precise control technology of tissue properties, and automation Production line construction related technologies. At present, the University of Science and Technology Beijing has cooperated with Harber Industrial Ltd., Shanghai Fuchi High-Tech Co., Ltd., Shenzhen Element Technology Co., Ltd., Yangzhou Haichang New Materials Co., Ltd., Suzhou Chuangji Precision Manufacturing Co., Ltd., Beijing More than ten companies, including Jiarun Powder Injection Molding Technology Co., Ltd., Xiamen Juci Technology Co., Ltd., and Beijing Chuangzhuo Technology Co., Ltd., have established strategic partnerships to jointly devote themselves to near-net-shape manufacturing technology and injection molding of high-performance special powder materials. Product promotion. The project products are not only used in the China Academy of Engineering Physics, the 12th Research Institute of China Electronics Technology Group Corporation, the 9th Research Institute of China Electronics Technology Group Corporation, the 13th Research Institute of China Electronics Technology Group Corporation, and the 50th Research Institute of China Electronics Technology Group Corporation. It has been applied by national defense units such as the Fifth Research Institute, China Shipbuilding Industry Corporation, and the 703 Institute of the First Academy of China Aerospace Science and Technology Corporation, solving many "stuck" problems in the development of national defense equipment. At the same time, the project products have also achieved significant economic and social benefits among the high-tech products of well-known domestic and foreign companies such as first-line consumer electronics brands and automobile brands in the industry.

2. Application effect

The project team is the first team to conduct research on injection molding technology in my country. The project lasted for 18 years and led and promoted the formation and development of my country's injection molding industry. The project applied for 142 invention patents (including 1 PCT patent), including 52 authorized invention patents, 68 authorized utility model patents, and published 133 papers, forming a nearly complete high-performance special powder material with my country's completely independent intellectual property rights. shape manufacturing technology. The project team has led and promoted the formation and development of my country's injection molding industry through technology transfer or cooperation, publishing papers, holding industry forums and academic conferences, and sending graduates, achieving a virtuous cycle of industry-university-research-promotion. . Since 2010, the project team has cooperated with Harber Industrial Ltd., Shanghai Fuchi High-Tech Co., Ltd., Shenzhen Elite Technology Co., Ltd., Yangzhou Haichang New Materials Co., Ltd., and Suzhou Chuangji Precision Manufacturing Co., Ltd. and other companies have reached a strategic partnership and are committed to the promotion of near-net-shape manufacturing technology and injection molding products of high-performance special powder materials. At present, Harber Industrial Ltd. and Shanghai Fuchi High-tech Co., Ltd. have developed into two major injection molding enterprises with high rankings in the industry and relatively objective production scale. Among them, Jiangsu Harber Industrial Ltd. has been established in October 2017. It was successfully listed on the GEM of Shenzhen Stock Exchange in September. In 2010, my country's injection molding market size was only about 140 million yuan. In 2014, my country became the world's largest country in terms of injection molding sales. In 2017, it reached about 5.5 billion yuan, accounting for more than 1/3 of the world market. The technology of this project has been promoted and applied in more than a dozen companies, and 54 production lines have been built. In the past three years, new sales of 3.95 billion yuan and new profits of 790 million yuan have been achieved, with significant social and economic benefits.

The project products have broken the foreign technology blockade, solved many "stuck" problems in the development of national defense equipment, and met the country's major needs, which is of great significance. At present, the core parts and components needed by my country's manufacturing industry are heavily dependent on imports. Developing the core basic parts and components needed by my country's manufacturing industry, strengthening the industrial foundation, and changing China's manufacturing industry is a core task of "Made in China 2025". High-performance special powder materials are a type of core basic components with special properties and difficult preparation techniques. They play an irreplaceable key role in both national defense equipment and civilian high-tech products, directly affecting the overall integrity of key devices or equipment. performance or reliability. This project developed a near-net-shape manufacturing technology for high-performance special powder materials, which solved the problem of being unable to prepare complex-shaped special material products due to high hardness, brittleness, and sensitivity to processing conditions, and achieved low-cost Near-net-shape manufacturing overcomes the problem of low performance of traditional materials, laying the foundation for achieving lightweight, miniaturization and high performance of key components or equipment. Project products such as tungsten electrodes, porous tungsten cathode substrates, aluminum nitride coil frames, aluminum nitride support rods, honeycomb structural profiles and other products have been used in key national defense equipment, meeting the urgent need for special powder material products for my country's key national defense equipment. , and at the same time laid the foundation for the development of new national defense equipment in the future and the further improvement of performance. This will drive technological progress in my country's weapons, electronics, atomic energy industry, electric vacuum, automobile, aerospace, machinery manufacturing and other related industries, and help the efficient application of my country's advantageous resources.

Relying on this project, a large number of engineering and scientific and technological talents in the field of injection molding have been trained. They have become leading talents and technical backbones of the injection molding industry in my country and even the world, providing strong talent support for the development of the industry.

Powder injection molding is an energy-saving, efficient, environmentally friendly and disruptive green manufacturing technology that has significant energy-saving and emission-reduction effects. This technology can reduce or even eliminate machining. It is a highly near-net-shape forming technology that greatly improves production efficiency, high material utilization, reduced resource consumption, low production costs, and significant effects in saving materials and energy consumption. It also provides new ways for the high-value utilization of China's advantageous resources and the development of high value-added products.

As stated in the summary, the project broke through technical bottlenecks such as special powder preparation, near-net shape and structural properties control, formed high-performance special powder material near-net shape manufacturing technology and key equipment with independent intellectual property rights, and built a world-class The two largest injection molding companies lead the development of the industry. In the past three years, new sales have reached 3.95 billion yuan and new profits have reached 790 million yuan, producing significant economic, social and environmental benefits. The data comes from the accounting statements of each application unit, financial certificates approved and issued by the unit's financial department, etc. New sales are the new product sales resulting from the application of the project technology by the application unit, based on the contract that has been signed and performed; new profit is the new sales of the application unit minus the costs, fees and taxes of related products or services the balance after.