Overview of Laser Additive Manufacturing in China

By: Minlin Zhong

Tsinghua University

The booming Chinese economy has created a favorable environment for the research, development, application and market in the area of high-power lasers and especially laser additive manufacturing (LAM) in China. In a so-called “world manufacturing center,” laser additive manufacturing, as a modern advanced manufacturing technology, plays an important role in the manufacturing and re-manufacturing areas. There are great needs in China to fabricate high-value components or difficult-to-fabricate components by conventional methods.

Re-manufacturing is also a huge market in China to refurbish used or worn high-value components like blades, rollers, molds and many other components, not only to save the value but also to save the resources and protect the environment. For these reasons, the Chinese government has launched a clear policy to strongly support the technology R&D and business development in the re-manufacturing industry as a green resource-recycle industry. In October 2009, China Technology Innovation Strategic Alliance for Resources Recycling Industry (CIAR) was established as a national alliance.

As a developing country, China pays intensive attention to lasers and laser applications. There are five national laser technology research centers, about 45 universities (research teams) and 20 research institutes focusing on R&D in the area. About 200 laser companies provide crystal, component, accessory, laser, laser system, application and technological service and about 130 laser job shops located in major cities in China. This year, the Chinese lasers and laser applications overall market is estimated to reach 7 to 8 billion RMB (approximately $1 billion). Many laser manufactures witnessed a 30% increase this year compared to last year. The forecasted laser and application market in China in the following five years is about 60 billion RMB.

Among the various laser manufacturing technologies such as cutting, welding, drilling, marking, etc., the Chinese scientists and engineers spend much more time and efforts on LAM covering laser surface modification, laser remelting, laser alloying, laser cladding, selective laser sintering and melting and laser direct manufacturing based on multi-layer powder feeding cladding. In the past 25 years, the Chinese authors have published the highest percentage of papers on laser cladding in international journals (43% of SCI indexed papers and 45% of EI indexed papers), in addition to about 1,700 papers published in Chinese journals. These continuous research efforts have resulted in some major technological developments and breakthroughs in the LAM area. For example, the direct additive manufacturing of large titanium components for airplanes (microstructure control and deformation control in layer upon layer additive manufacturing for large components), laser deposition repairing of various engine blades including the blades made by directional solidified nickel-based super alloy. Additional examples are developments of particulate reinforced metal matrix composite coating materials for severe wear, corrosion and fatigue environments, research on functional gradient materials or structures, laser deposition of micro/nano powder mixture, selective laser melting to produce complex and fine components and laser micro-cladding for circuit board, micro-scale device and sensors. Some major universities in the LAM area include, but are not limited to, Tsinghua University, Huazhong University of Science and Technology, Beihang University, Northwestern Polytechnical University, South China University of Technology, Zhejiang University of Technology, Shanghai Jiaotong University and Institute of Metal Research, Chinese Academy of Sciences.

In China, about five Chinese companies provide high power (1~20kW) CO2 lasers, ten Chinese companies provide high power laser processing systems (integrated with domestic or imported lasers) and about 50 job shops offer service related to LAM. The major companies in this area include, but are not limited to, Hans Laser, Huagong Laser, Unity-Prima Laser and Dalu Laser, etc.

Based on the many years of development, China has established a favorable environment such as a favorable government policy, a huge current and potential market, a strong fundamental and application oriented research, some proven technologies for materials, coatings and additive manufacturing of components (manufacturing and re-manufacturing), system engineering and equipment development, equipment or technological products and some successful industrial applications and business demonstrations. What is needed in China in the LAM area includes high quality/cost effective lasers dedicated for LAM like fiber lasers, disk lasers or diode lasers, high quality accessories such as integrated mirrors, scanning mirrors, beam optimization, such as optical components and coaxial nozzle/powder feeders, system engineering technologies like process monitoring and close-loop control and novel and proven application technologies.