INTRODUCTION TO THERMAL SPRAY LABORATORY

(TSL-XJTU)

The Thermal Spray Laboratory (TSL-XJTU) was found in 1993. The laboratory is attached to the School of Materials Science and Engineering, Xi'an Jiaotong University. It is one of research groups in the State Key Laboratory for Mechanical Strength of Materials.

The vision of the TSL is to perform the cutting-edge R&D in thermal spray field in terms of both fundamental researches and application researches. The application researches are aimed at finding basic solutions for various industries through development of High Performance Protective Coatings including superhard wear resistance coating, corrosion resistance coatings, thermal barrier coatings (TBCs) for different severe operating conditions. Typical coating materials include WC-Co and Cr₃C₂-NiCr cermet, ZrO₂-based oxide (YSZ, ScSZ) ceramics, intermetallic compound such as FeAl and NiAl systems.

The development of functional coatings is also the subject pursued in this laboratory aiming at fabrication technology development of functional device through layering of coatings. Two current major projects are focused on fabrication technology development of SOFC (Solid Oxide Fuel Cells) and DSC (Dye-sensitized Solar Cells). The formation of effective nanostructured TiO₂ photocatalytic coatings is also one on-going project.

The fundamental researches are focusing on the understanding of coating formation process mechanisms, microstructure evolution and control, characterization of coating microstructure and properties, the relationships between coating microstructure and properties. Most of the fundamental projects are supported by government foundations. Since 1995, the lab's projects have been continuously supported by National Natural Science Foundation of China, the Ministry of Science and Technology of China, and the Ministry of Education of China, and other government fundings. Many practical application case investigations have been also supported by industries.

The laboratory has wide connections with famous thermal spray labs around world, especially with the thermal spray center of Osaka University (previously directed by Prof. Ohmori), Japan, LERMPS (Laboratory for Research and Development of Materials Surface Processing) of UTBM (Technological University of Belfort-Montbeliad), France (Directed by Prof. C. Coddet), and Thermal Spray Lab of Nanyang Technological University, Singapore (directed by Prof. K.A. Khor), the Center of Thermal Spray of StonyBrook Uinversity, and Southern Carolina University, USA, . The laboratory's projects have been also supported by foreign companies, including IHI, Japan, Honeywell, USA, Plasma Geken, Japan.

The main R&D on-going projects include:

1)      Fundamentals on thermal spraying including splat formation and quantitative characterization of lamellar microstructure by visualization of the pore-net inherent to thermal spray coating, coating formation mechanisms, development and controlling of microstructure of the coating;

2)      Cold spraying for development of potential superhard cermet coatings, intermetallic coating, cost-effective bond coat for TBCs, and nanotructured coatings

3)      Plasma spraying for creation of new generation thermal barrier coatings (TBCs);

4)      Nano-structured ceramics preforming and Assembly by nano- and submicrometers ceramics particles by Vacuum cold spraying

5)      HVOF (High velocity oxy-fuel) for high performance cermet coating;

6)      Solid oxide fuel cell (SOFC) fabrication by thermal spray processes;

7)      Dye-sensitized solar cell (DSC) assembly by newly developed Vacuum cold spray system

8)      Preparation of high performance photocatalytic coatings;

The TSL-XJTU is equipped with many thermal spray facilities for the research and development activities. In this laboratory, different spray deposition systems were developed as their first kinds in China at the time being, for example, HVOF in 1995, Cold spray system in 2001, Micro-plasma system in 1997, Liquid flame spray system in 1999, and particle temperature and velocity measurement system in 1999. In 2004, a vacuum cold spray equipment (also referred to as low pressure cold spray system) was installed in the lab. In 2011, PS-PVD system was installed. Besides domestical thermal spray system, the lab have also installed JP-8000 HVOF, CS2000 (Plasma-Giken) and GTV plasma spray systems. 

The laboratory is directed by Prof. Chang-Jiu Li, who joined Xi'an Jiaotong University after he worked in this field at Osaka University for 9 years. Prof. Li's pioneering work on the quantitative characterization of plasma-sprayed ceramic coating has greatly contributed the understanding of the real lamellar structural features of plasma-sprayed coatings and the structural factors dominating coating properties. The results have been widely cited to explain the microstructure features and coating properties change, especially compared with the identical bulk materials. The research results on HVOF cermet coatings and metallic coatings have contributed the understanding of formation mechanisms and fundamental approaches to control coating microstructure and performance. The results achieved on splashing mechanisms during splat formation lead to the understanding of real factors determining the splashing.

Up to now, over 750 academic papers were published, including over 430 papers in the peer-reviewed international journals, over 100 papers in the peer-reviewed Chinese journal and over 220 papers in the conference proceedings. He have also contributed to five chapters for five English books on thermal spraying and cold spraying, with a total pages of about 300. Besides, Co-edited one long chapter on thermal spraying in Chinese for 80 pages for the book “China Materials Engineering Handbook” . The published papers have cited by other researches totally for over 10,000 times.  Moreover, over 50 patents have been approved. The laboratory warmly welcomes all researches who are interested in our concerns for collaboration program.