Effects of reflectivity on laser-ablation resistance of the laser-cladding repaired Nd2O3 modified SiO2 coatings on C/C composites

High Temperature Oxidation and Oxyacetylene Ablation Properties of ZrB2-ZrC-SiC Ultra-High Temperature Composite Ceramic Coatings Deposited on C/C Composites by Laser Cladding

“…B4C + 2Zr + Si = 2ZrB2 + SiC (10) The Gibbs free energy ΔG at room temperature ~3000 K of the above equations was found by HSC6.0 software (V6.0, 2006, Outokumpu Technology, Outokumpu, Finland), and the Gibbs free energy ΔG at different temperatures T was calculated and plotted, as shown in Figure 3. As can be seen from Figure 3, ΔG value of reaction (8) is the lowest at the same temperature, so from a thermodynamic point of view, reaction (8) will take precedence, resulting in the formation of ultra-high temperature ceramics ZrB2 and ZrC phases. The Si in the original powder mixture will react with the generated part of ZrC and the remaining B4C according to reaction (9) to form ZrB2 and SiC phases.…”

“…Among them, the main preparation technologies for anti-oxidation coatings include pack cementation, chemical vapor deposition (CVD), plasma spraying, slurry painting, sol-gel, reactive infiltration, chemical vapor reaction (CVR), in situ formation, laser cladding, etc. [5][6][7][8][9][10][11][12]. The main matrix modification technologies include chemical vapor infiltration/ deposition, precursor infiltration and pyrolysis, reactive melt infiltration method, slurry infiltration/impregnation, hot pressing method, etc.…”

“…In fact, there are many literature reports on the high-temperature oxidation resistance modification of C/C composites [14] or the preparation of high-temperature oxidation resistance coating on its surface [15]. However, the preparation of ZrB 2 -ZrC-SiC ultrahigh temperature composite ceramic coatings with resistance to 1600 • C on C/C composites based on laser cladding technology has not been reported in the literature [7][8][9][10][11][12]. Wang et al [7] prepared the inner Si-SiC-MoSi 2 and outer SiO 2 -Nd 2 O 3 double layer coating on C/C composites using slurry-based laser cladding technology.…”

“…The results show that the ablative resistance of the coating is improved. Wang et al [8] prepared the inner Si-SiC and outer SiO 2 -Nd 2 O 3 double layer coating on C/C composites using slurry-based laser cladding technology. The ablative properties of 1-7 s with 300/500 W fiber laser with wavelength of 1060-1090 nm were studied.…”

Functional gradient films on aluminum alloy to improve its laser‐induced damage ability and reduce pollutant particles’ generation

“…Similarly, Walter and coworkers 24 fabricated a tunable, F I G U R E 2 Flowchart of heat generation analysis angle-and polarization-independent, large-area perfect absorber with an absorption rate greater than 97% over the wavelength of 825-1025 nm that was based on large area, low-cost colloidal lithography, and dry-etching. However, both reports used brittle substrates (Si, 25 TiN/glass, 26 SiO 2 , 27 and ceramics 28 ) that cannot be used as frames in indirectly driven ICFs. Furthermore, films at hundreds Laser-induced damage of dielectric materials can be attributed to photo-ionization, 29 the valence-electron density, 30 and the free-electron density.…”