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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2020, Vol. 41 ›› Issue (9): 423553-423553.doi: 10.7527/S1000-6893.2019.23553

• Material Engineering and Mechanical Manufacturing • Previous Articles     Next Articles

Microstructure refinement mechanism and properties of Ti-based rare earth laser cladding layers

ZHANG Tiangang1, ZHUANG Huaifeng2, XUE Peng1, ZHANG Qian3, YAO Bo3, LI Baoxuan2   

  1. 1. Engineering Techniques Training Center, Civil Aviation University of China, Tianjin 300300, China;
    2. Sino-European Institute of Aviation Engineering, Civil Aviation University of China, Tianjin 300300, China;
    3. College of Aeronautical Engineering, Civil Aviation University of China, Tianjin 300300, China
  • Received:2019-10-09 Revised:2019-11-16 Online:2020-09-15 Published:2019-12-26
  • Supported by:
    National Natural Science Foundation of China (51371125); Fundamental Research Funds for the Central Universities (3122018D013)

Abstract: TC4+Ni45+Co-WC Ti-based wear-resistant composite coatings with different Y2O3 additions (0wt% and 3wt%) were prepared on the surface of TC4 alloy by using TRUMPF TruDisk 4002 fiber laser. The microstructure, microhardness, and tribological properties of the coatings were analyzed by using XRD, SEM, EDS, EPMA, microhardness tester, and friction and wear apparatus. The results show that there are no cracks, pores, and other defects on the two coating surfaces, and the formation phases are consistent, mainly including TiC, TiB2, Ti2Ni, WC and α-Ti. In 0wt%Y2O3 coating, there is an obvious microstructure segregation and the size of the precipitated phase is coarse with the evident dendrite orientation. In 3wt%Y2O3 coating, the microstructure is uniformly dispersed and the refinement effect is significant. According to Bramfitt two-dimensional lattice misfit calculation, the misfit between (100)Y2O3 and (100)Ti2Ni, (111)Y2O3 and (110)TiC, and (110)Y2O3 and (101-0)TiB2 are 5.75%, 6.72% and 10.10%, respectively. The ability of Y2O3 acting as an effective heterogeneous nucleus to refine Ti2Ni, TiC and TiB2 is Ti2Ni > TiC > TiB2. The microhardness of 0wt%Y2O3 coating and 3wt%Y2O3 coating is 600-630 HV0.5 and 470-480 HV0.5, which is 62% and 26% higher than that of the substrate. 3wt%Y2O3 coating shows the best wear resistance and anti-friction. The wear volume and friction coefficient are 47.8% and 5.0% lower than those of 0wt%Y2O3 coating, and the wear mechanism is mainly abrasive wear.

Key words: Y2O3, TC4, laser cladding, two-dimensional lattice misfit, microstructure, friction and wear

CLC Number: