Surface Ablation Research Articles

Effect of long-wavelength perturbations in nonlinear evolution of the ablative Rayleigh–Taylor mixing

We investigate herein how long-wavelength perturbations affect the nonlinear evolution of the multimode ablative Rayleigh–Taylor instability (ARTI). A single-mode ARTI with an initial small amplitude is first investigated to validate the reliability of the proposed simulation code. The results show that both linear growth rates and asymptotic bubble velocities obtained from simulations are in reasonable agreement with theoretical results. Initial perturbations with different long-wavelength perturbations are compared to investigate the contribution of the long-wavelength perturbations to the nonlinear evolution of the ARTI mixing. Beyond the nonlinear saturation limit [S. W. Haan, Phys. Rev. A 39, 5812 (1989)], the long-wavelength perturbation promotes the ARTI mixing and facilitates the development of the large-scale structure on the ablation surface. In the self-similar analysis, the simulation results indicate that the self-similar growth parameters decrease with increasing initial longest-wavelength modes.

Ablation of selected thermoplastic polymers using an Nd:YAG laser

This article presents the results of a study on laser ablation of selected thermoplastic polymers using an economical fiber laser with a scanning galvanometer system and an IR laser with a wavelength of λ = 1064 nm. The study aimed to develop comparative characteristics of the ablation processes of commonly used constructional thermoplastics, namely acrylonitrile butadiene styrene terpolymer (ABS), polystyrene (PS), poly(ethylene terephthalate) (PET), polylactide (PLA), and polyamide 6 (PA6). The ablation characteristics of the tested materials were determined, and the ablation depth and surface structures were calculated and presented. A comparative analysis of the contact angle, surface free energy, and strength of adhesive connections of materials modified with laser radiation and unmodified was performed. The study showed that the dynamics of laser ablation were much higher in ABS, PS, PET, and PC than in PLA and PA6. Although modification of the surface layer of the polymeric material did not have a significant impact on the surface free energy and wettability of the sample surface, it increased the strength of adhesive connections even several times (in ABS, PS, PET) with the lowest energy consumption. The results also demonstrated that some polymers, such as ABS or PS, can be effectively treated with near-infrared laser radiation of this wavelength, which is particularly important for surface layer modification and marking of details.

High aspect ratio sapphire micromachining by ultraviolet laser‐induced plasma‐assisted ablation (LIPAA)

AbstractThe ultraviolet laser‐induced plasma‐assisted ablation performed in this article can attain deep and high‐quality engravings in sapphire without necessitating volatile solutions or expensive equipment such as high‐power ultrashort‐pulsed lasers. The dominant mechanism of ablation is discovered to be from the direct ablation of excited sapphire surfaces and not from the plasma generated from the target material. Only an initial deposition from the target is needed to initiate the direct ablation. Note that 20‐µm wide, 30‐µm deep channel and hole features with a surface roughness (Sa) of .65 µm are achieved at an etching rate of .3 µm per pulse without the need for extensive cleaning. Engravings can reach up to 150‐µm depths at a maximum tapering angle of 5° until the shrinking absorbent surface vanishes, and 500‐µm wide 430‐µm deep topside through‐cutting is achieved. This study characterizes the morphology of direct laser ablation of transient absorbent sapphire surfaces. This method demonstrates the potential for the low‐cost rapid engraving of high aspect ratio features in transparent sapphire substrates.

Symmetric offset versus asymmetric offset ablation with transepithelial refractive keratectomy

BackgroundIn eyes with hyperopia, astigmatism, and mixed astigmatism Transepithelial photorefractive keratectomy (TransPRK) is a modality of surface ablation surgery. We center on the corneal vertex for all our treatments (all have an offset to the center of the pupil) and wanted to compare the visual results of symmetrical profile treatments versus asymmetrical profile treatments (the center of the treatment on the vertex and the boundaries with the pupil center) using TransPRK as corneal refractive surgery. Methods We retrospectively analyzed two consecutive groups of eyes treated with TransPRK in the Aurelios Augenlaserzentrum Recklinghausen: 47 eyes treated with symmetrical offset and 51 eyes treated with asymmetrical offset. The intergroup comparisons were assessed using unpaired Student’s T-tests, whereas preoperative to postoperative changes were assessed using paired Student’s T-tests.ResultsRefractive outcomes were good for both groups. 83 and 88% of eyes were within the spherical equivalent of 0.5 D from the target in the symmetric and asymmetric offset groups, respectively. 85 and 84% of eyes had a postoperative astigmatism of 0.5 D or lower in the symmetric and asymmetric offset groups, respectively.ConclusionWe have not found a significant difference in the refractive outcomes between the symmetric group and the asymmetric group of eyes treated both with TransPRK for preoperatively hyperopic or mixed astigmatism.

Evaluation of particle release during cleaning of coated surfaces with pulsed Nd:YAG laser

The released particles during laser-based surface ablation of an epoxy resin coating were investigated for their number, size, mass and chemical composition. The laser used was a pulsed Nd:YAG laser with a maximum average power of 91 W. During the experiments, the applied laser power was investigated as a varying parameter. With the highest power, a maximum particle count of 4.3*108 particles/cm³ was measured, which corresponds to a mass of approximately 55 mg/m³. With decreasing laser power, the particle loading of the aerosol decreases. The particle sizes are bimodal distributed between 10 nm and approximately 3 μm. The first peak is at 34 nm and the second peak is at 630 nm. In terms of number, the nanoparticles dominate the distribution. During the analysis of the particles, fractal and spherical particles were determined, whereby the fractal particles are mainly in the nanometre range and the spherical particles mostly in the μm range. The chemical analysis of the particles showed that they consist of carbon and hydrogen.

Investigation of corneal epithelial thickness and irregularity by optical coherence tomography after transepithelial photorefractive keratectomy

ABSTRACT Clinical relevance Corneal epithelial healing after refractive surgery is a clinically significant issue, especially for surface ablation procedures, and this can be monitored using optical coherence tomography (OCT). Background The aim of this work is to investigate the corneal epithelial thickness and irregularity by OCT after transepithelial photorefractive keratectomy (t-PRK) and analyse its correlation with visual and refractive outcomes. Methods Patients aged ≥18 years with myopia, with or without astigmatism, who underwent t-PRK between May 2020 and August 2021 were included. All participants were subjected to complete ophthalmic examinations and OCT pachymetry at every follow-up visit. Patients were followed up at 1 week and 1, 3, and 6 months postoperatively. Results A total of 67 patients (126 eyes) were enrolled in this study. One month postoperatively, spherical equivalent refraction and visual acuity achieved preliminary stability. However, central corneal epithelial thickness (CCET) and standard deviation of the corneal epithelial thickness (SDcet) took 3–6 months to progressive recovery. Patients with higher baseline spherical equivalent refraction were associated with slower epithelial recovery. At every follow-up time point, a significant superior-inferior difference in the minimum corneal epithelial thickness area was observed. Higher stromal haze was correlated with higher spherical equivalent refraction (both baseline and residual) but had no relation with visual outcomes. There was a significant correlation between higher CCET with a better uncorrected distance visual acuity and lower corneal epithelial thickness irregularity. Conclusions CCET and SDcet measured by OCT seem to be a good auxiliary indicator for reflecting the status of corneal wound recovery after t-PRK surgery. However, a well-designed randomised control study is needed to confirm the study results.

Post-LASIK dry eye disease: A comprehensive review of management and current treatment options.

Laser-assisted in situ keratomileusis (LASIK) is a unique corneal stromal laser ablation method that uses an excimer laser to reach beneath corneal dome-shaped tissues. In contrast, surface ablation methods, such as photorefractive keratectomy, include removing epithelium and cutting off the Bowman's layer and the stromal tissue of the anterior corneal surface. Dry eye disease (DED) is the most common complication after LASIK. DED is a typical multi-factor disorder of the tear function and ocular surface that occurs when the eyes fail to produce efficient or adequate volumes of tears to moisturize the eyes. DED influences quality of life and visual perception, as symptoms often interfere with daily activities such as reading, writing, or using video display monitors. Generally, DED brings about discomfort, symptoms of visual disturbance, focal or global tear film instability with possible harm to the ocular surface, the increased osmolarity of the tear film, and subacute inflammation of the ocular surface. Almost all patients develop a degree of dryness in the postoperative period. Detection of preoperative DED and committed examination and treatment in the preoperative period, and continuing treatments postoperatively lead to rapid healing, fewer complications, and improved visual outcomes. To improve patient comfort and surgical outcomes, early treatment is required. Therefore, in this study, we aim to comprehensively review studies on the management and current treatment options for post-LASIK DED.

Noble-Metal Nanoparticle-Embedded Silicon Nanogratings via Single-Step Laser-Induced Periodic Surface Structuring.

Here, we show that direct femtosecond laser nanostructuring of monocrystalline Si wafers in aqueous solutions containing noble-metal precursors (such as palladium dichloride, potassium hexachloroplatinate, and silver nitrate) allows for the creation of nanogratings decorated with mono- (Pd, Pt, and Ag) and bimetallic (Pd-Pt) nanoparticles (NPs). Multi-pulse femtosecond-laser exposure was found to drive periodically modulated ablation of the Si surface, while simultaneous thermal-induced reduction of the metal-containing acids and salts causes local surface morphology decoration with functional noble metal NPs. The orientation of the formed Si nanogratings with their nano-trenches decorated with noble-metal NPs can be controlled by the polarization direction of the incident laser beam, which was justified, for both linearly polarized Gaussian and radially (azimuthally) polarized vector beams. The produced hybrid NP-decorated Si nanogratings with a radially varying nano-trench orientation demonstrated anisotropic antireflection performance, as well as photocatalytic activity, probed by SERS tracing of the paraaminothiophenol-to-dimercaptoazobenzene transformation. The developed single-step maskless procedure of liquid-phase Si surface nanostructuring that proceeds simultaneously with the localized reduction of noble-metal precursors allows for the formation of hybrid Si nanogratings with controllable amounts of mono- and bimetallic NPs, paving the way toward applications in heterogeneous catalysis, optical detection, light harvesting, and sensing.

Intra-Annual Variability of the Surface Ablation of the Aldegondabreen Glacier (Spitsbergen)

The intra-annual variability of the surface ice ablation on the 5.5 km2 Aldegondabreen glacier (Spitsbergen Island, Barentsburg area) is presented. The ice ablation was measured during five seasons (2018–2022) at the two stakes, installed in the lower part of the glacier and at the index site, where the amount of ablation numerically coincides with the glacier-averaged value with the r = 0.99 agreement. The temporal resolution of the ice ablation data is uneven and varies from 3 to 45 days. To carry out the correlation analysis, meteorological data from the automated weather station located near the glacier terminus are used. The ice ablation rates, obtained after normalization for the number of days between stake readings, have a tight correlation with both the air temperature and the downwelling shortwave radiation flux for most of the seasons, in 2018–2021 (r = 0.71–0.99). Surface air temperature and short-wave radiation are closely related; the above estimates indicate the leading role of short-wave radiation in the summer ablation of the glacier in the period 2018–2021. The year 2022 became anomalous, as the correlation with the shortwave radiation significantly decreased (r = 0.21–0.34). The European heat wave of 2022, which also affected the Svalbard archipelago, interrupted the ordinary intra-annual variability of the air temperature, causing the unprecedented ice melt on Aldegondabreen in September. The predicted increase in frequency and intensity of the future heat waves will result in an increased role of turbulent fluxes in the surface energy balance of the low-elevated Svalbard glaciers. The article demonstrates how the empirically identified dependencies can change from season to season in a non-stationary climate.

Ablation behavior of C/C–Zr1-xHfxC-SiC composites under an oxyacetylene flame at above 2500 °C

In order to enhance ablation resistance of C/C composites, Zr1-xHfxC and SiC were introduced into C/C composites, and ablation behavior of the composites was studied. In the composites (CHZS), HfC and ZrC produced a solid solution, and solid solubility of HfC in ZrC was 0.4, which indicated that the solid solution was defined to be Zr0.6Hf0.4C. Compared with C/C–ZrC–SiC composites (CZS), CHZS possessed a better ablation resistance. During ablation of CHZS, Zr0.6Hf0.4C is oxidized to produce HfO2 and ZrO2, and HfO2 particles played a pinning effect, which fixed molten oxide coating. Moreover, due to low CTE of HfO2 and decreasing content of ZrO2, there was a smaller thermal stress and its distribution area on CHZS ablation surface, thus thermal stress corrosion was weakened to strengthen integrity of oxide coating. In this case, a complete and continuous HfO2-ZrO2 coating was formed on CHZS surface, which could resist oxygen diffusion and reduce oxidation rate of the composites.

Integrated Intelligent Method Based on Fuzzy Logic for Optimizing Laser Microfabrication Processing of GnPs-Improved Alumina Nanocomposites

Studies on using multifunctional graphene nanostructures to enhance the microfabrication processing of monolithic alumina are still rare and too limited to meet the requirements of green manufacturing criteria. Therefore, this study aims to increase the ablation depth and material removal rate and minimize the roughness of the fabricated microchannel of alumina-based nanocomposites. To achieve this, high-density alumina nanocomposites with different graphene nanoplatelet (GnP) contents (0.5 wt.%, 1 wt.%, 1.5 wt.%, and 2.5 wt.%) were fabricated. Afterward, statistical analysis based on the full factorial design was performed to study the influence of the graphene reinforcement ratio, scanning speed, and frequency on material removal rate (MRR), surface roughness, and ablation depth during low-power laser micromachining. After that, an integrated intelligent multi-objective optimization approach based on the adaptive neuro-fuzzy inference system (ANIFS) and multi-objective particle swarm optimization approach was developed to monitor and find the optimal GnP ratio and microlaser parameters. The results reveal that the GnP reinforcement ratio significantly affects the laser micromachining performance of Al2O3 nanocomposites. This study also revealed that the developed ANFIS models could obtain an accurate estimation model for monitoring the surface roughness, MRR, and ablation depth with fewer errors than 52.07%, 100.15%, and 76% for surface roughness, MRR, and ablation depth, respectively, in comparison with the mathematical models. The integrated intelligent optimization approach indicated that a GnP reinforcement ratio of 2.16, scanning speed of 342 mm/s, and frequency of 20 kHz led to the fabrication of microchannels with high quality and accuracy of Al2O3 nanocomposites. In contrast, the unreinforced alumina could not be machined using the same optimized parameters with low-power laser technology. Henceforth, an integrated intelligence method is a powerful tool for monitoring and optimizing the micromachining processes of ceramic nanocomposites, as demonstrated by the obtained results.

Combining endoscopic mucosal resection with hybrid argon plasma coagulation to reduce local colorectal lesion recurrence: a video tutorial.

Endoscopic mucosal resection (EMR) is a safe, effective, and surgery-sparing technique for removing large colorectal lesions [1]. Although piecemeal EMR is recommended for polyps > 20 mm in size, it remains a suboptimal technique for complete lesion resection, with high rates of residual polyp and recurrence rates reaching 15 % [2]. Hybrid argon plasma coagulation (hAPC) is a novel approach allowing ablation of resection margins and surface after EMR. hAPC combines waterjet injection and argon plasma coagulation (APC) in a single device. On-demand, repeatable saline cushioning without instrument exchange reduces thermal ablative insult to deep tissue structures, allowing for effective destruction of micro-remnants with reduced risk of perforation. High technical success and low recurrence rates (0 %) were shown in a pilot study using EMR in combination with hAPC [3]. A prospective international multicenter study showed that the local recurrence rate was only 2.2 % when using hAPC after EMR [4]. One recent meta-analysis found the local recurrence rate to be 3.3 % after hot EMR and margin ablation at 12-month follow-up [5].

Laser-induced dielectric to conductor transformation on the surface of aluminium nitride ceramic

In this work formation of conductive lines on the surface of AlN ceramic induced by laser radiation is presented. The transformation to conductive state is done be ablation of the ceramic surface using nanosecond Nd:YAG laser. The dependences of the processing conditions as applied laser fluence and the pulse overlapping on the resistance value are obtained for different surface modifications including straight lines, ∟, and ┼ shapes. The formation of conductive structures is also studied for application of laser irradiation at the second (532 nm), third (355 nm) and fourth (266 nm) harmonics of the laser system. It is found that the resistance strongly depends on the processing conditions, as at appropriate choice it can be varied in a range of order of magnitude. Processing parameters windows are defined where the structure resistance has a minimal value. The performed analyses based on TEM, SEM, EDX, and Raman spectroscopy indicate that formation of aluminium layer, its oxidation and morphology define the processed areas conductivity. The role of oxidation is also confirmed by analyses of structures fabricated in vacuum, where significant reduction of the resistance is observed. It is found however, that a decrease of the ambient air pressure to 10 Torr is sufficient to obtain structures resistance of the same order as for processing in vacuum. Calculated data about the thickness of the conductive layer is also presented. The obtained results could be used in the design of microelectronic components, resistive elements, and novel optical materials.

MICRONEEDLES A POSSIBLE SUCCESSOR TECHNOLOGY FOR TDDS: A PATENT ANALYSIS

The market size for transdermal drug delivery systems was assessed at USD 5.9 billion in 2020 and is expected to reach USD 8.4 billion by 2028, expanding at a compound annual growth rate (CAGR) of 4.5% from 2021 to 2028. Micro Jet injectors, iontophoresis, electroporation, sonophoresis, microneedles, powdered injection, surface ablation, jet injectors and stripping by tape are some of the methods that enhance the delivery and ease of administration of larger molecules which is the major hindrance in case of Transdermal drug delivery system (TDDS). This type of delivery offers immediate delivery and avoids lag time. Microneedles are hollow cannulas inserted into the skin at 50 µm to 500 µm. The microneedle drug delivery systems market is projected to register a CAGR of 7.8% during the forecast period of 2022-2027. The microneedle drug delivery systems market is segmented by product type (solid, hollow, coated, and dissolvable), application (drug delivery, vaccine delivery, dermatology, and other applications), and geography (North America, Europe, Asia-Pacific, Middle-East and Africa, and South America). This review summerizes the recent patents granted in the area of micro-needling in the year 2022 and also the commercial market of microneedles until now.

Microstructure and Ablation Behavior of C/C-SiC-(ZrxHf1-x)C Composites Prepared by Reactive Melt Infiltration Method.

C/C-SiC-(ZrxHf1-x)C composites were prepared by the reactive melt infiltration method. The microstructure of the porous C/C skeleton and the C/C-SiC-(ZrxHf1-x)C composites, as well as the structural evolution and ablation behavior of the C/C-SiC-(ZrxHf1-x)C composites, were systematically investigated. The results show that the C/C-SiC-(ZrxHf1-x)C composites were mainly composed of carbon fiber, carbon matrix, SiC ceramic, (ZrxHf1-x)C and (ZrxHf1-x)Si2 solid solutions. The refinement of the pore structure is beneficial to promote the formation of (ZrxHf1-x)C ceramic. The C/C-SiC-(ZrxHf1-x)C composites exhibited outstanding ablation resistance under an air-plasma environment at around 2000 °C. After ablation for 60 s, CMC-1 appeared to possess the minimum mass and linear ablation rates of only 2.696 mg/s and -0.814 µm/s, respectively, which are lower than those of CMC-2 and CMC-3. During the ablation process, a Bi-liquid phase and a liquid-solid two-phase structure were formed on the ablation surface which could act as an oxygen diffusion barrier to retard further ablation, which is responsible for the excellent ablation resistance of the C/C-SiC-(ZrxHf1-x)C composites.

Real-Time In-Process Evaluation of Spatter Area and Depth of Aluminium Surface in a Pulsed Laser Ablation Process Using Received Radio Frequency Power from Plasma Plumes

During the pulsed laser ablation of metals, as well as other materials, the development of a plasma plume close to the ablated surface leads to the emission of radio frequency energy. In this paper, we describe a process for analysing the received radio frequency power (RFP) for an aluminium (Al) surface ablation process in atmosphere using picosecond laser pulses at a wavelength of 1064 nm. The analysis of the RFP was carried out on two sets of experiments, where two parameters of the laser (repetition rate of laser (RRL) and power of laser (PL)) were varied while other parameters remained constant. In addition to the RFP measurement during the laser processing, the spatter area (SA), which is defined in this paper, and the depth of the ablated hole were measured post-process using a 3D microscope. It was observed that there is a direct relationship between (RFP)2 and SA. Accordingly, an appropriate RF calibration was performed, which leads to the definition of a quantity called the RF regulation % (RFR%). By comparing the RFR and PL/RRL variations, to which the laser beam fluence is proportional in these experiments, a diagnostic process (i.e., flowchart) for real-time depth evaluation was proposed and experimentally confirmed. This diagnostic process can indicate if the depth of the laser ablated crater is less than or exceeds a predetermined depth, which in this study was set to 15 µm. It is also demonstrated that the SA variation can be estimated in real-time by analysing the received RF power and, secondly, the depth of ablation can be measured in real time using a combination of information from the received RF power and laser parameters.

Efficient surface processing of high surface quality with two-color double-pulse femtosecond laser ablation

We investigate the femtosecond laser ablation of 304 stainless steel (AISI 304), aiming to achieve a high ablation rate, while maintaining low surface roughness. We observe that the surface ablation with 1030 nm-wavelength laser pulses shows a higher ablation rate than that with the 515 nm-wavelength pulses, whereas the surface roughness obtained with the 1030 nm pulses is significantly higher as compared to that obtained with the ablation of 515 nm pulses. We also show that by the use of the two-color double-pulses at 1030 and 515 nm wavelengths, a much higher ablation rate has been achieved with a surface roughness comparable to that obtained with the ablation of 515 nm pulses.

Ablation oxidation and surface quality during laser polishing of TA15 aviation titanium alloy

TA15 titanium alloy is sensitive to temperature, and it is one of the main materials used in aircraft bearing parts that operate for long periods of time at 500 °C. The thermomechanical processing of this alloy is difficult to control because of its high activity and oxidation. In the present research, nanosecond pulse lasers of various powers were used to polish the TA15 surface. The surface morphology, microstructure evolution, oxidation depth and mechanical properties were investigated. The results revealed that the initial sample has a rough surface, and both high-power and low-power lasers can significantly decrease the surface roughness. Three methods, SEM morphology analysis, EDS line scanning and EDS mapping, are used to detect the oxidation depth of the polished zone. The TEM images and XRD patterns show typical Al2O3, Ti2O3 and TiO2 constituents, which affect the tensile strength of the alloy. A low-power laser has a better polishing effect than a high-power laser; the oxidation depth with a high power is approximately 100 μm, while the oxidation depth with a low power is less than 10 μm. The polished surface roughness parameters Ra (arithmetical mean deviation of the profile) and Sa (arithmetical mean height of the scale limited surface) obtained with a low-power laser are reduced from approximately 6 μm–3.197 μm and 4.298 μm, respectively.

Influence of the transition layer material on the etched pattern of multilayer films

High-quality frequency-selective surfaces (FSSs) exert a crucial role in the absorption and filtration of electromagnetic signals. FSS is made from structure-function-integrated materials with a patterned metal layer cover. Cr or Ni transition layers are usually arranged between the material substrate and the metal layer to enhance their bonding. However, the study on the removal behavior of Al/glass and Al/Ni/glass films by laser ablation with a pulse width of 100 ns of the 1064 nm laser found that the Ni transition layer increases the damage threshold of Al films because its thermophysical parameters changed the laser absorption rate of the Al surface and the spatial temperature distribution inside the Al film. The experimental results show that four characterized areas in the laser ablation surface are identified in the machined grooves when the laser energy density is 12 J/cm2, indicating that the multilayer films are mainly removed by vaporization, phase explosion, melting, and fragmentation. It is found that the removal mechanism of the Al/Ni/glass system is dominated by melting heat stress and fragmentation, so splashing is obvious and results in residual recondensation droplets of micrometer size. The above results provide ideas and methods for other high-quality laser processing of structure-function-integrated film systems.

Thermal Ablation Experiments of Carbon Phenolic and SiC-Coated Carbon Composite Materials Using a High-Velocity Oxygen-Fuel Torch

For future spacecraft TPS (heat shield) applications, ablation experiments of carbon phenolic material specimens with two lamination angles (0° and 30°) and two specially designed SiC-coated carbon-carbon composite specimens (with either cork or graphite base) were conducted using an HVOF material ablation test facility. The heat flux test conditions ranged from 3.25 to 11.5 MW/m2, corresponding to an interplanetary sample return re-entry heat flux trajectory. A two-color pyrometer, an IR camera, and thermocouples (at three internal locations) were used to measure the specimen temperature responses. At the 11.5 MW/m2 heat flux test condition, the 30° carbon phenolic specimen's maximum surface temperature value is approximately 2327 K, which is approximately 250 K higher than the corresponding value of the SiC-coated specimen with a graphite base. The 30° carbon phenolic specimen's recession value is approximately 44-fold greater, and the internal temperature values are approximately 1.5-fold lower than the corresponding values of the SiC-coated specimen with a graphite base. This indicates that increased surface ablation and a higher surface temperature relatively reduced heat transfer to the 30° carbon phenolic specimen's interior, leading to lower internal temperature values compared to those of the SiC-coated specimen with a graphite base. During the tests, a phenomenon of periodic explosions occurred on the 0° carbon phenolic specimen surfaces. The 30° carbon phenolic material is considered more suitable for TPS applications due to its lower internal temperatures, as well as the absence of abnormal material behavior as observed in the 0° carbon phenolic material.