TY - JOUR
T1 - Ablation and insulation performance of Al2O3/PI coatings deposited by wide-velocity range high-energy plasma spraying
AU - Zhu, J. Y.
AU - Xu, K. Y.
AU - Tu, Y. M.
AU - Wang, Y.
AU - Bai, Y.
AU - Du, Y. H.
N1 - Publisher Copyright:
© 2026 Elsevier B.V.
PY - 2026/9/1
Y1 - 2026/9/1
N2 - Transient plasma ablation and molten aluminum contamination are major degradation modes of resin-based insulating supports in electromagnetic rail launchers. In this work, Al2O3/polyimide (PI) composite coatings with different thermoplastic/thermosetting PI ratios (TPI/TSPI = 10:0, 7:3, 5:5, and 3:7) were deposited on glass fiber reinforced epoxy resin substrates by wide-velocity-range high-energy plasma spraying. The TPI/TSPI ratio affected the powder thermal response, splat spreading, coating defects, and residual layer stability after ablation. PI73 showed a balanced coating structure and exhibited the lowest mass ablation rate of 0.024 g·s−1 after 150 plasma ablation cycles, corresponding to a 78.9% reduction compared with the resin substrate, while retaining a flexural strength of 232.61 MPa. After molten aluminum erosion, the Al2O3/PI coating maintained volume resistivities above 1010 Ω·cm. Ablation and erosion results indicated that the retained Al2O3-rich framework, PI-derived carbonaceous products, and lamellar coating structure contributed to residual layer integrity and molten aluminum penetration resistance. The proposed regulation strategy for the ratio of thermoplastic to thermosetting resins offers a novel design route for protective coatings against synergistic erosion by high temperature and molten aluminum.
AB - Transient plasma ablation and molten aluminum contamination are major degradation modes of resin-based insulating supports in electromagnetic rail launchers. In this work, Al2O3/polyimide (PI) composite coatings with different thermoplastic/thermosetting PI ratios (TPI/TSPI = 10:0, 7:3, 5:5, and 3:7) were deposited on glass fiber reinforced epoxy resin substrates by wide-velocity-range high-energy plasma spraying. The TPI/TSPI ratio affected the powder thermal response, splat spreading, coating defects, and residual layer stability after ablation. PI73 showed a balanced coating structure and exhibited the lowest mass ablation rate of 0.024 g·s−1 after 150 plasma ablation cycles, corresponding to a 78.9% reduction compared with the resin substrate, while retaining a flexural strength of 232.61 MPa. After molten aluminum erosion, the Al2O3/PI coating maintained volume resistivities above 1010 Ω·cm. Ablation and erosion results indicated that the retained Al2O3-rich framework, PI-derived carbonaceous products, and lamellar coating structure contributed to residual layer integrity and molten aluminum penetration resistance. The proposed regulation strategy for the ratio of thermoplastic to thermosetting resins offers a novel design route for protective coatings against synergistic erosion by high temperature and molten aluminum.
KW - Ablation resistance
KW - AlO/PI composite coating
KW - Plasma spraying
KW - Thermoplastic/thermosetting polyimide
UR - https://www.scopus.com/pages/publications/105043739577
U2 - 10.1016/j.surfcoat.2026.133742
DO - 10.1016/j.surfcoat.2026.133742
M3 - 文章
AN - SCOPUS:105043739577
SN - 0257-8972
VL - 535
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
M1 - 133742
ER -