Options
Investigation on the high temperature tribological behaviors of pristine and plasma-based Mo-Si-Ti coated γ-TiAl
Citation
Li, F., Zhang, P., Wei, D., Rawat, R. S., Ouyang, B., Liang, R., Jia, H., & Tai, R. (2024). Investigation on the high temperature tribological behaviors of pristine and plasma-based Mo-Si-Ti coated γ-TiAl. Surface and Coatings Technology, 494(Part 3), Article 131512. https://doi.org/10.1016/j.surfcoat.2024.131512
Author
Li, Fengkun
•
Zhang, Pingze
•
Wei, Dongbo
•
•
Ouyang, Bo
•
Liang, Rongqing
•
Jia, Hepeng
•
Tai, Rongjian
Abstract
A Mo-Si-Ti coated γ-TiAl substrate was fabricated using plasma alloying technology to enhance its high temperature wear resistance. The coated substrate was composed of a deposition layer and a diffusion layer, with the grain size decreasing from the substrate toward the coating, forming a gradient structure. XRD and TEM analysis revealed that the deposition layer included the (Ti, Mo)5Si3, TiSi and MoSi2, while the diffusion layer consisted of the γ-TiAl, TiSi and Al8Mo3. Nanoindentation results showed that the coated substrate exhibited high hardness (19.6 GPa), as well as high plastic deformation resistance and load-bearing capacity. Furthermore, the presence of residual compressive stress (−1255.9 MPa), stress concentrations at interfaces between different phases and gradient structure contributed to the high surface fracture toughness of the coated substrate. Wear testing indicated that the lower nanomechanical properties of pristine substrate combined with the dynamic cyclic generation of oxide film during high temperature friction caused to an increase in specific wear rate at loads of 4.2 N and 6.2 N. However, post-oxidation hardness elevation as well as the lubrication and supportive effect of extensively covered oxide film reduced the wear rate as load increased to 8.2 N. The transition from residual compressive stress to tensile stress along with the formation of oxides at grain boundaries reduced the surface fracture toughness of the coated substrate. Meanwhile, the rapid formation and spalling of oxide film resulted in an increase in the specific wear rate of the coated substrate with increasing load. Nevertheless, coated substrate exhibited better wear resistance than pristine substrate owing to its higher surface mechanical properties. The specific wear rates of the coated substrate were 3.7, 6.0 and 19.5 × 10−5 mm3N−1 m−1 at loads of 4.2, 6.2 and 8.2 N, respectively, reflecting reductions of 88.9 %, 84.3 %, and 34.6 % compared to the pristine substrate.
Date Issued
2024
Publisher
Elsevier
Journal
Surface and Coatings Technology
Project
RI 7/22 RSR
Grant ID
12304020
52475243
BK20230909
30923011013
ZR2023ME209
2022xjrc437
2024xjrc132
Funding Agency
National Natural Science Foundation of China
Natural Science Foundation of Jiangsu Province
Fundamental Research Funds for the Central Universities, China
Natural Science Foundation of Shandong
Project of the Talent Introduction of Dezhou University
National Institute of Education, Singapore