The problem of “stuck neck” is prominent, how should my country’s laser remanufacturing technology develop?

This article is from WeChat official account:Journal of Chinese Academy of Engineering (ID: CAE-Engineering)< / span> , author: Yao Zhe He, Yao Jianhua, the clever, article taken from Chinese Academy of Engineering published “China Engineering Science” 2020 the third period, the original title: “strategic Research Shu Research on Laser Remanufacturing Technology and Application Development”, head picture from: Vision China

Editor’s press

The scientific research team of Academician Xiang Qiao of the Chinese Academy of Engineering wrote an article in the journal of the Chinese Academy of Engineering, “Chinese Engineering Science”, starting from the macro demand of laser remanufacturing technology, combing the development and application status of laser remanufacturing technology, and condensing laser remanufacturing technology And the challenges faced by the industry in the development process, and then put forward the phased development goals for 2025, 2035 and 2050. In response to the current problems and challenges of laser remanufacturing technology in my country in terms of special materials, core devices, remanufacturing concepts and standard systems, the article proposes: strengthen active guidance at the strategic level; construct a laser additive remanufacturing material genome system; improve standardization System and high-level application-oriented talent training system; increase application promotion and guide industry integration; establish cooperation platforms to accelerate the innovation and development of key common technologies to provide support for the development of laser remanufacturing technology and its industry.

I. Preface

Key components of high-end equipment, such as hot-end parts of aero-engines, ultra-supercritical steam turbine rotors and blades, railway tracks, metallurgical equipment, etc., are prone to structural and surface damage due to the harsh service environment, leading to shutdown or scrapping of high-end equipment. If the idea of full life cycle manufacturing is used, rapid remanufacturing or on-site remanufacturing can extend the service time of wearing parts, realize the reuse of resources, and promote sustainable development. “Made in China 2025” clearly pointed out: fully implement green manufacturing and vigorously developIn the remanufacturing industry, implement high-end remanufacturing, intelligent remanufacturing, and in-service remanufacturing, promote product certification, and promote the sustainable and healthy development of the remanufacturing industry.

Laser remanufacturing technology uses high-power laser beams as the heat source and uses non-contact optical processing to provide new solutions for parts repair and remanufacturing. It is an important supporting technology for green remanufacturing. This technology can quickly restore the size of products or parts, and reach or exceed new products in performance. It has the advantages of high repair accuracy, small damage to the workpiece, high bonding strength of the repair area, and high material utilization. Facing the repair needs of key components in different fields, scholars at home and abroad have carried out theoretical and experimental research mainly on laser cladding of iron-based, titanium-based, cobalt-based, and nickel-based alloy materials. The basic research on the application of laser remanufacturing technology has been carried out in the fields of coal mine machinery [, high-pressure oil pump camshafts, etc.]. However, laser remanufacturing technology has only achieved industrial applications in a few fields, and there are still certain technical and market bottlenecks for large-scale applications.

For laser remanufacturing technology and industry, based on the analysis of its development status, this article sorts out the current technical problems and application challenges, and studies and judges development trends, and proposes to promote the development of laser remanufacturing technology and industry in my country Suggestions.

2. Analysis of the macro demand for laser remanufacturing technology

(1) Laser remanufacturing technology is the frontier field of manufacturing technology innovation

Laser remanufacturing technology can be used for pre-processing, shaping repair and post-processing of laser remanufacturing, the specific classification is shown in Figure 1. Among them, the core link is the laser forming repair technology, such as the use of laser cladding forming, laser rapid prototyping, and laser welding processes to repair defective parts. In addition, laser cutting and laser cleaning technology can be used in the disassembly and pre-processing of parts, and laser shock strengthening and laser polishing can be used in the post-processing of repaired parts.

Figure 1 Laser Remanufacturing Technology Classification

Laser additive remanufacturing technology based on laser cladding forming and laser rapid prototyping has the advantages of being able to use a stable molten pool to form a metallurgical bond, the interface bonding strength is much higher than coating and spraying, and the heat input is less than arc surfacing. , It can meet the remanufacturing needs of high-strength parts and is an important frontier development direction of advanced manufacturing technology. In view of the severe repair requirements of some large-scale equipment and key parts, special repair technology and multi-energy field laser remanufacturing technology have become current research hotspots.

(2) Laser remanufacturing industry is an emerging industry that promotes the transformation and upgrading of manufacturing industry

Laser remanufacturing technology occupies an advantage in high-end equipment remanufacturing, and is considered to be a new generation of strategic support technology for manufacturing transformation and upgrading. The laser remanufacturing industry, formed by the development of laser remanufacturing technology, provides development impetus for the transformation and upgrading of the manufacturing industry.

The laser remanufacturing industry has become an industry with significant economic and social benefits in developed countries or regions such as Europe and the United States, which has greatly promoted the transformation and upgrading of the manufacturing industry. In order to promote the development of the laser remanufacturing industry, major countries or regions in the world have successively formulated a series of strategic recommendations and policy support (see Table 1) span>. At present, my country has become a major manufacturing country, but compared with developed countries or regions, the degree of refinement of manufacturing technology still needs to be improved. In addition, under the development requirements of energy saving and emission reduction, my country has gradually paid attention to the field of laser remanufacturing industry, and launched a series of strategies and policies to support the development. In recent years, my country’s laser repair and remanufacturing technology has initially formed industries in aviation, aerospace, mining machinery, turbine equipment, metallurgical equipment and other fields, and has been widely used in the remanufacturing of power equipment such as coal mine hydraulic supports, metallurgical rolls, and steam turbine rotors. The laser remanufacturing industry has become an emerging industry that promotes the transformation and upgrading of the manufacturing industry.

Table 1 Laser remanufacturing technology and industry-related strategies and policies in major countries or regions in the world

(3) Laser remanufacturing industry is an important force to promote sustainable development

“Made in China 2025” regards green manufacturing as one of the five major projects, and clearly points out that special technologies such as energy efficiency improvement, cleaner production, water-saving and pollution control, and recycling of traditional manufacturing should be organized and reformed. The laser remanufacturing industry is highly compatible with the concept of green manufacturing, providing important support for the sustainable development of traditional manufacturing.

Laser remanufacturing technology has the characteristics of concentrated heat input, small damage to the workpiece, and fast processing speed. It is an emerging green remanufacturing technology. Laser remanufacturing technology can achieve rapid repair of key components and reduce waste of resources, reduce energy and economic losses caused by downtime, and promote sustainable development. In addition, the laser remanufacturing industry has fewer “three wastes” emissions and controllable pollution sources during the manufacturing process, which is highly compatible with my country’s construction of a circular economy and is conducive to the deployment and implementation of energy-saving and emission-reduction strategies.

(4) Laser remanufacturing technology profoundly changes the design and operation of high-end equipment

The green, low energy consumption, and high-quality development of high-end equipment manufacturing has become a top priority, and the full life cycle management of key components has become an important trend in the development of high-end equipment. The emergence and use of laser remanufacturing technology has perfected the connotation of the full life cycle management of key components. Specifically, the repair possibility of key components should be considered in the design stageIn the service phase, information feedback such as service life should be considered, and in the scrapping phase, non-destructive decomposition and other scrapping methods should be considered. At the same time, by strengthening the exploration of product failure analysis and remaining life change rules, the design and preparation of high-performance surface coatings for failed parts of parts and the processing and quality control of weak parts can be realized.

The full life cycle manufacturing model will effectively control manufacturing pollution from the source, make up for the losses caused by equipment operation stalls, and subvert the traditional manufacturing model. The laser repair and remanufacturing technology, as a key part of it, has profoundly changed the design thinking and operation mode of manufacturing equipment.

3. Current status of laser remanufacturing technology development

(1) Application of laser remanufacturing technology in the repair of parts and components in different industrial fields

With the continuous development of high-power lasers and their supporting equipment, more and more countries have strengthened the theoretical and technical research on laser remanufacturing technology in the field of mechanical parts manufacturing and repair. As shown in Figure 2, laser remanufacturing technology has been practically applied in industrial fields such as aviation, aerospace, defense industry, mining machinery, energy and power, and metallurgical equipment. The application of laser remanufacturing technology abroad is mainly concentrated in the defense industry and aviation and aerospace fields, such as the application of laser remanufacturing technology to repair failed aero-engine parts.

Figure 2 Laser remanufacturing technology for different industrial fields

my country’s laser remanufacturing technology is mainly used in the military field to build a core technology system for remanufacturing key components of military aircraft engines; in the civil industry, laser remanufacturing technology has been used in mining machinery, energy power , Metallurgical equipment and other fieldsHydraulic supports, steam turbine rotors and blades, metallurgical roller tables, mandrels, rolling mill arches and other large equipment and key parts have been applied in the repair. Among them, the laser remanufacturing technology of coal mine hydraulic supports has been applied in batches.

(2) Energy field assisted laser remanufacturing has become an important means of high-quality remanufacturing

Facing high-quality repair and on-site repair of key parts of high-end equipment, single energy beam laser metal forming technology has defects such as pores, residual stress, and microcracks, which affect the performance and stability of repaired parts. Therefore, it is difficult to meet the remanufacturing requirements of high-end equipment for precision, complexity, and high performance only by changing the laser process.

Students at home and abroad propose to use electromagnetic field, induced thermal field, ultrasonic vibration and other external energy field coupling to act on the laser remanufacturing process( See Figure 3). Specifically, for narrow and deep defect repair problems and strict requirements for no pores, electromagnetic fields are introduced to adjust the flow of the molten pool and suppress pores; for components that have strict requirements on microstructures, ultrasonic energy fields are introduced to regulate the morphology of the tissue; for easy cracking Materials or parts, introduce thermal field to reduce temperature gradient and reduce the risk of residual stress. Currently, energy field-assisted laser remanufacturing technology has become a research hotspot, but related technologies are still in the laboratory development and prototype development stages. Facing the needs of industrial applications, there is an urgent need to continue research and development in the finalization of composite manufacturing processes and energy field composite integration equipment to meet the future high-quality and high-efficiency repair needs of high-end equipment.

Figure 3 The mechanism of action of the external energy field in laser remanufacturing
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(3) On-site remanufacturing is an important development direction of laser remanufacturing technology

Faced with the need for repairing large-scale equipment or large-scale parts that are large in size and difficult to transport, the outstanding advantages of laser on-site remanufacturing technology can quickly realize the recovery of damaged equipment. In order to facilitate on-site remanufacturing, laser equipment needs to be miniaturized, integrated, and easy to transport to adapt to the complex on-site environment and maintain high stability.

When the laser cladding remanufacturing technology is used to repair large equipment or parts, especially the laser repair of non-horizontal base surface damage, the shape of the molten pool is prone to change under the action of gravity, which is proposed for the multi-angle laser remanufacturing process Higher requirements. To this end, Shi Shihong’s research team adopted laser cladding technology with optical powder feeding, and controlled the laser cladding head to be perpendicular to the base surface at different inclination angles to achieve full-angle laser cladding. The Yao Jianhua research team studied the influence of working airflow and cladding angle on the quality of laser repaired rotor shaft, and realized laser repair under different inclination angle conditions.

Four. Challenges facing the development of laser remanufacturing technology

The equipment repair and remanufacturing industry represented by laser remanufacturing technology is a derivative industry of the equipment manufacturing industry. Although my country’s laser remanufacturing technology has been applied first in the fields of mining machinery, energy and power, metallurgical equipment, etc., with the development of the high-end equipment industry, more new requirements have been placed on laser remanufacturing technology and the industry, such as aeroengines. Laser remanufacturing technology for high-end equipment represented by gas turbines. At present, my country’s laser remanufacturing industry does not match the industrial scale of the manufacturing industry. The industrial development has problems such as “small, scattered, weak” and few application fields, and there is a lack of large-scale and strong international leading enterprises. The application and development of laser remanufacturing technology in my country are facing the following challenges.

(1) The development of special materials for laser remanufacturing lags behind

The problem of “stuck neck” of special materials for laser remanufacturing in my country is prominent. The specific manifestation is that the development of special new materials such as powder and wire for laser remanufacturing is relatively lagging, and the selection of special materials is limited. Larger, facing problems such as fewer varieties, fewer suppliers, and lack of high-performance repair materials, and the reliability and stability of proprietary materials are generally low and lack verification. At present, foreign companies have developed a series of special materials for laser additive manufacturing technology. For example, the German SLM Laser Company (SLM Solutions) has developed a series of laser additive manufacturing materials such as aluminum-based, nickel-based, titanium-based, cobalt-based, iron-based, and copper-based, and has established a stable process system with self-produced equipment. Foreign equipment manufacturers usually adopt the “equipment + powder” bundling sales policy when exporting, making my country’s import of special materials expensive, increasing product costs and reducing its competitiveness in the field of laser additive remanufacturing.

(2) Import of core equipment and components is dependent on imports

China has certain equipment research and development capabilities in the field of laser remanufacturing, but it still focuses on the integrated development of equipment for industrial applications, and its core components, such as high beam quality lasers and beam shaping systems , High-quality electron guns and high-speed scanning systems, high-power laser scanning galvanometers, dynamic focus mirrors, array-type high-precision nozzles/sprinklers and other precision components are still heavily dependent on imports. Domestic laser manufacturing equipment is in terms of process stability and environmental temperature control. There is still a big gap with imported brands. China currently has a group of internationally influential equipment manufacturers such as Han’s Laser Intelligent Equipment Group and Huagong Laser Engineering Co., Ltd., but the high-end laser equipment market is still dominated by advanced foreign companies, such as TRUMPF Group(Trumpf), Apache (IPG), American Coherent Laser Company(Coherent), (Laserline), etc.

(3) Enterprises have insufficient understanding and knowledge of laser remanufacturing technology

Laser remanufacturing technology provides a new solution for high-end equipment repair and remanufacturing, but this technology has not been widely accepted and recognized by the equipment industry. The specific reasons are as follows: On the one hand, some traditional equipment companies are less sensitive to new technologies and need to strengthen their promotion and awareness; on the other hand, when introducing laser remanufacturing technology in a certain equipment field, they need to go through rigorous measures. Scientific analysis and complete process verification, and blindly introducing new technologies will bring equipment operation risks. In addition, in the product life cycle management, product and material design needs to consider parts and componentsMaintenance and remanufacturing, while traditional equipment components are designed without laser remanufacturing for component repair. Therefore, some equipment components are difficult to apply laser remanufacturing technology due to structural forms or material selection restrictions.

(4) Industry standards and systems are not sound

In the field of laser repair and remanufacturing, my country has already established “Laser Repair Technical Terms and Definitions”, “Laser Repair General Technical Specifications” and other national standards, as well as some machinery industry standards and corporate standards, but has not yet established a complete Laser remanufacturing technology standard system, which restricts the accumulation, curing, promotion and application of related technological achievements. Due to the lack of a unified industry standard system, some companies have insufficient scientific consideration of material selection and technology in the laser repair process, resulting in failure of repair parts, property losses and even safety accidents, which in turn brings about the promotion of laser remanufacturing technology in the industry Had a negative impact.

V. Development goals of laser remanufacturing technology

In recent years, with the continuous development of laser repair and remanufacturing technology, my country’s laser remanufacturing industry has begun to take shape. It is estimated that the scale of my country’s laser repair and remanufacturing industry will reach about 2 billion yuan in 2019, and laser remanufacturing technology has shown great application potential in the field of industrial repair. In the future, with the further improvement of repair quality, efficiency, and intelligence, laser remanufacturing technology will be further promoted and applied, which will have a profound impact on equipment design concepts, industrial structure, and manufacturing services. Taking into account the innovation of technology, industry, and concept, the future development goals of laser remanufacturing technology in phases are as follows.

(1) Development goals for 2025

Docking the remanufacturing development strategy proposed by “Made in China 2025”, aiming at the urgent need to improve repair quality and efficiency of key parts of high-end equipment, and solving the current “small, scattered and weak” status of the laser remanufacturing industry, By 2025, the development goals of laser remanufacturing technology and industry are: to comprehensively improve the level of laser remanufacturing equipment, materials, and processes, and continue to meet the requirements of high-quality remanufacturing, on-site remanufacturing, Demand for in-service remanufacturing technology; improve the overall efficiency of laser remanufacturing and its pre- and post-processing processes to meet the demand for high-efficiency remanufacturing; docking the “two machines” localization strategy to solve the “two machines” hot end parts and other core component repair needs ; With scale as the development goal, in technological development andExpansion of application fields and industrial scale on the basis of cost reduction. It is estimated that by 2025, my country’s overall laser remanufacturing industry scale will reach 10 billion yuan.

The key development directions for 2025 are: At the technical level, focus on the development of laser composite remanufacturing and its key equipment, high-speed/ultra-high-speed/broadband laser remanufacturing equipment and processes, and hot ends of complex shapes High-quality laser additive remanufacturing technology for components, synchronous detection and control in the laser remanufacturing process, laser remanufacturing technology in harsh on-site environments; forming a laser composite equipment manufacturing industry, repair service industry, repair special powder and wire industry ; Laser remanufacturing technology extends to multiple fields and its parts, forming a large-scale on-site laser remanufacturing service industry.

(2) Development goals for 2035

Service-oriented manufacturing has become the main direction of manufacturing transformation and upgrading, and laser remanufacturing technology is an important supporting technology for recycling and remanufacturing services. In order to support the distributed laser remanufacturing service system, By 2035, the development goal of laser remanufacturing technology and industry is: Intelligent laser remanufacturing technology is becoming more mature, and laser repair of parts and components will be automated and convenient. Operation; laser repair and remanufacturing technology form a standardized system; to meet the needs of different industrial fields for laser intelligent repair technology, form a mature laser remanufacturing industry chain. It is estimated that by 2035, the scale of my country’s laser remanufacturing industry will reach 50 billion yuan.

The key development directions for 2035 are: At the technical level, focus on the development of automatic defect identification and repair process intelligent specification technology, laser intelligent repair and remanufacturing technology, and laser remanufactured parts life precision prediction technology ; Four major industries including laser remanufacturing equipment, intelligent control systems and software, repair materials, and remanufacturing services have been formed.

(3) Development goals for 2050

The harmonious development of man and nature is the only way for the development of human civilization. With the penetration of renewable products and the concept of circular economy, remanufacturing technology will become popular and domestic. By 2050, the development goals of laser remanufacturing technology and industry are: miniaturized laser rapid repair equipment and supporting process technology are mature; achieve laser remanufacturing under extreme conditions and environments; manufacturing services with laser remanufacturing as the core technology are at high-end Popularization of the equipment industry.

The key development direction towards 2050 is: at the technical levelFocus on the development of precise monitoring of small damages and precise repairs at the microstructure level; laser remanufacturing in extreme environments such as deep sea, space, and bipolar; high-end equipment sales will transform into a high-end equipment service industry and become the mainstream; laser remanufacturing technology supports regenerative products and The popularity of circular economy.

Six. Suggestions for the development of laser remanufacturing technology

(1) Strengthen active guidance at the strategic level

It is recommended to increase financial support for key areas such as laser remanufacturing special materials, core equipment and components. Make full use of funding channels such as national major special projects and national key R&D plans, adopt a combination of universities, research institutes, enterprises, and users, and continue to promote the development of general-purpose equipment and processes, and focus on supporting model-oriented Research and development of special laser remanufacturing equipment, materials and processes for wearing parts.

(2) Establish a laser additive remanufacturing material genome system

The continuous development of laser additive remanufacturing technology puts forward higher development requirements for special materials. Due to the non-equilibrium metastable characteristics of special materials, compared with traditional materials, the design and development of special materials are more difficult, longer cycle, and more complex. Traditional methods have been unable to meet the current development needs. Therefore, it is recommended to establish a laser additive remanufacturing material genome system with its own characteristics as soon as possible, improve the non-equilibrium metastable characteristics of special materials, and establish a high-throughput calculation basis and theory with its own genome.

(3) Speed up the establishment and improvement of a standardized system and a high-level application-oriented talent training system

It is recommended to improve the ability of laser remanufacturing technology and product research and development, inspection and certification, strive to promote the close integration of standardization and industry, and establish a complete laser remanufacturing industry development standard system. Strengthen international cooperation, actively connect with the International Organization for Standardization, and carry out the establishment, transformation and improvement of related standards. At the same time, focusing on the lack of professional talents and industry norms in the field of laser remanufacturing in my country, relying on the country’s existing talent training and introduction policies, we will continue to improve the construction of the training system for high-level applied talents.

(four) addLarge application promotion efforts to guide industry integration

It is recommended to combine government support with various industry resources, strengthen the links between the various sub-fields of my country’s laser remanufacturing industry, and broaden the industry and the government, upstream and downstream of the industry chain, between industries, and between manufacturers and users The docking channel to speed up the promotion and application of technology. Focus on the implementation of hierarchical and field-specific special pilot demonstration actions, point-to-point integration, coordinated advancement, actively guide and promote the input of social forces and local governments, and jointly promote the in-depth application of laser remanufacturing technology, and promote laser remanufacturing in my country The remanufacturing industry continues to develop rapidly.

(5) Strengthen collaborative innovation of “production, study, research and application” and accelerate the development of key common technology innovations

It is recommended to establish a national R&D platform in the fields of laser remanufacturing, full life cycle manufacturing, etc., led by universities, scientific research institutes and key enterprises to open up the upstream and downstream of the industry chain to form a complete material , Equipment, technology, testing, and application systems to accelerate the research and innovation of key common technologies. Facing different industry sectors, set up distinctive remanufacturing industry alliances, remanufacturing product evaluation and testing centers, and collaborative innovation centers.

Note: The content of this article has been slightly adjusted, you can view it if necessaryOriginal .

Author introduction

Xiang Qiao, female, is an aero-engine technology and engineering management expert, and an academician of the Chinese Academy of Engineering.

He has been engaged in the research of aero-engine technology and engineering management for a long time, presided over the completion of 17 scientific research projects including the research and development of advanced aero-engine blades and other key parts remanufacturing technology, as the engine maintenance line of the third-generation fighter of our army The person in charge of the construction project solved key issues such as remanufacturing of key components, control system repair and failure mechanism and prevention, proposed a maturity model for military aero engine maintenance line construction engineering management, created aero engine maintenance engineering management system, and led the completion of Type 3 The construction project of our army’s advanced aviation engine maintenance line has significantly improved our army’s aviationEngine independent maintenance and support capability.

This article is from WeChat official account:Journal of Chinese Academy of Engineering (ID: CAE-Engineering)< / span> , author: Yao Zhe He, Yao Jianhua, the clever

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