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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2021, Vol. 42 ›› Issue (7): 424139-424139.doi: 10.7527/S1000-6893.2020.24139

• Material Engineering and Mechanical Manufacturing • Previous Articles     Next Articles

Microstructure and properties of TiC-TiB2 composite phase Ti-based rare earth laser cladding layers

ZHANG Tiangang1, ZHANG Qian2, ZHUANG Huaifeng3, LI Baoxuan3, XU Yutong3   

  1. 1. Institute of Civil Aviation Technology, Civil Aviation University of China, Tianjin 300300, China;
    2. College of Aeronautical Engineering, Civil Aviation University of China, Tianjin 300300, China;
    3. Sino-European Institute of Aviation Engineering, Civil Aviation University of China, Tianjin 300300, China
  • Received:2020-04-25 Revised:2020-05-21 Published:2020-10-16
  • Supported by:
    National Natural Science Foundation of China (51371125); The Fundamental Research Funds for the Central Universities (3122018D013); Tianjin Research Innovation Project for Postgraduate Students (2019YJSS077)

Abstract: Wear-resistant TC4+Ni45+Co-WC+Y2O3 multi-channel overlapping Ti-based composite coatings with different Y2O3 mass fractions are cladded on TC4 by the TRUMPF 4002 coaxial powder feeding fiber laser. The microstructure of the coatings is tested and analyzed using XRD, SEM, EDS and EPMA. The microhardness and tribological properties of the coatings are analyzed by a microhardness tester, a friction and wear tester and a white light profiler. The results show that the phases in the coatings remain unchanged with different Y2O3 additions, mainly including Ti2Ni, TiC, TiB2 and α-Ti. In the coating without Y2O3, the phases are large in size with obvious directionality. With the addition of Y2O3, the microstructure of the coatings is gradually refined, and the directionality of the phases is weakened. When the Y2O3 addition is 3wt%, the precipitates in the coating are mainly particles and short rods, and a large number of TiC-TiB2 dependent growth composite phases are synthesized in the coating. Based on the two-dimensional lattice misfit calculation, the misfit δ between TiB2(0001) and TiC(111) is 0.912%, with TiC and TiB2 forming the coherent interface, thereby effectively increasing the distribution uniformity of the coating microstructure. With the addition of Y2O3, the microhardness of the coating decreases gradually, the wear volume of the coating first increases and then decreases, and the friction coefficient of the coating decreases gradually. The antifriction and wear resistance of the 3wt% Y2O3 coating are the best under the action of the TiC-TiB2 dependent growth composite phase, with the wear mechanism of the coating being abrasive wear.

Key words: laser cladding, TC4, TiC-TiB2 composite phase, Y2O3, two-dimensional lattice misfit, friction and wear properties

CLC Number: