High-temperature Tests Research Articles

High-Temperature Thermal Stability of Hot Isostatic Pressed Co25.1Cr18.8Fe23.3Ni22.6Ta8.5Al1.7 (at%) Eutectic High-Entropy Alloy

An eutectic high-entropy alloy (EHEA) consisting mainly of a face-centered cubic (FCC) phase and a C14 Laves phase with the compositions of Co25.1Cr18.8Fe23.3Ni22.6Ta8.5Al1.7 (at%) was successfully prepared by hot isostatic pressing. The present EHEA exhibits a skeleton-type Laves phase structure, deviating from typical EHEA structures. After a series of annealing treatments at 1000 °C for different durations (ranging from 0 to 150 h), the Co3Ta phase precipitated after annealing. The mechanical properties measured at 850 °C showed a tensile strength of 441 MPa and an elongation of 3.3%. The results of the high-temperature tests showed that the mechanical properties of this alloy did not change significantly before and after annealing, and its microstructure showed a high degree of stability, which suggests that the material has some potential for use in high-temperature environments.

High-Temperature Creep and Microstructure Evolution of Alloy 800H Weldments with Inconel 625 and Haynes 230 Filler Materials

Alloy 800H stands as one of the few code-qualified materials for fabricating in-core and out-of-core components operating in high-temperature reactors. Welding is a common practice for assembling these components; however, the selection of a suitable filler material is essential for enhancing the high-temperature creep resistance of Alloy 800H weldments in high-temperature applications. In this study, Inconel 625 and Haynes 230 filler materials were used to weld Alloy 800H plates by employing the gas tungsten arc welding technique. The high-temperature tensile and creep rupture properties, microstructural stability, and evolution of the weldments after high-temperature exposure were investigated and compared with those of Alloy 800H. The results show that both weldments exhibit enhanced tensile and creep behavior at 760 °C. The creep rupture times of the weldments with Inconel 625 filler and Haynes 230 filler materials were about two and three time longer, respectively, than those of Alloy 800H base metal when tested at 80 MPa and 760 °C. Carbides (MC and M23C6) were commonly observed in the microstructures of both the weld and base metals in the two weldments after high-temperature creep tests. However, the Inconel 625 filler weldment displayed detrimental δ and Laves phases in the fusion zone, and these precipitates could be potential sites for initiating cracks following prolonged high-temperature exposure. This study shows that the weldment with Haynes 230 filler material exhibit better phase stability and creep rupture properties than the one with Inconel 625, suggesting its potential for use as a candidate filler material for Alloy 800H for further investigation. This finding also emphasizes the critical consideration of microstructural evolutions and phase stability in evaluating high-temperature materials and their weldments in high-temperature reactor applications.

Effect of inhomogeneous microstructure on the stress corrosion cracking behavior of 316LN stainless steel weld joint under high-temperature and high-pressure water small punch test

The stress corrosion cracking (SCC) behavior of 316LN stainless steels (SS) weld joint in high-temperature and high-pressure (HTHP) water were investigated by the newly developed HTHP water small punch test. The results indicated that SCC behavior of weld joint were strongly influenced by the inhomogeneous microstructure. Intergranular fracture dominated the SCC process of heat affected zone (HAZ) and partial hardening was believed to be the main reason for the increased sensitivity of HAZ to SCC. All samples exhibited cleavage fracture characteristics, indicating that film-induced cleavage dominated the SCC process of SS and its welded joints in HTHP water.

Research of the Bending characteristics of Aero Ball Joints at High Temperature and Pressure

As a piping element with excellent stress compensation performance, spherical joints are widely used in aerospace piping systems. However, in piping stress simulation, the presence of nonlinear features such as friction vice of the solid model of the spherical joints will lead to the difficulty of convergence of the calculations or the deviation of the results is too large, so in order to improve the convergence of the iterative process, “joint” joints are used to replace and simplify the original spherical joints, but this simplified calculation needs to accurately capture the characteristic parameters (such as bending stiffness and bending friction moment, etc). In order to improve the convergence of the iterative process, “joint” is usually used to replace and simplify the original spherical joint, but this simplified calculation needs to accurately capture the characteristic parameters of the spherical joint (e.g. bending stiffness and bending friction moment, etc.). This paper focuses on the bending characteristics of spherical joints by establishing a high-temperature and high-pressure test platform, and takes into account the difference between the test and the actual use of spherical joints, and further combines numerical simulation and BP neural network methods to predict the characteristics of spherical joints to meet the requirements of the actual use of spherical joints.

Preparation and decolorization of sapindus mukurossi extract and its application in sebum-control shampoos

BackgroundSapindus mukurossi extract (SME) is a kind of natural surface active ingredient with potential applications in cleansing products. However, the polyphenols and pigments contained in the extract may cause color browning of the products during storage especially at elevated temperatures, affecting its high level addition in the products. ObjectiveTo explore a decolorization process suitable for industrialization realize the high level addition of SME and explore the potential of SME in the field of controlling sebum esters. Materials and MethodsSME was prepared by adsorbing polyphenols on the D301 resin and oxidation decoloring oxidation. Investigated its sebum-control efficacy by SZ95 model and clinical study. ResultsThe results demonstrate that the D301 resin displays the best adsorption selectivity for polyphenols in SME, and the polyphenol adsorption ratio of D301 resin (5 wt%) can reach 83.6%; The optimal decolorization conditions are pH= 7.8, temperature 73 ℃ and decolorization time 5.7 h when H2O2 content is 6%, The prepared SME shows no obvious changes in color and retain stable during the high temperature (50 °C) test period of 28 days. 4 μg/mL of SME decreases the lipid synthesis of SZ95 cells by 24.8%. The clinic efficacy of the shampoo containing 10% SME (by dry extract weigh) is further evaluated. No significant changes in the skin moisture content and transepidermal water loss (TEWL) are observed within four weeks after using the product, while the scalp sebum level is significantly reduced. ConclusionIn this study, we prepared a light-colored, highly stable SME, enabled its high-level addition in cleansing and care products and found its sebum-control efficacy.

Effect of the addition of titanium filler on high temperature strength and microstructural characteristics of laser welded tube-end plug socket joints of molybdenum alloy

Three types of Mo alloy socket joints were prepared in this study: a joint without alloying (LW joint), a joint with a trace amount of titanium (Ti) added to the fusion zone (FZ) (LW-Ti-A joint), and a joint with Ti separately added to the FZ and the heat affected zone (HAZ) (LW-Ti-B joint). Tensile tests were carried out on the three types of joints at 360, 900, and 1200 °C. The results showed that the tensile strengths of the base metal (BM) of the Mo tubes were 368.7, 239.9, and 189.6 MPa at 360, 900, and 1200 °C, respectively. At all temperatures, the tensile strengths of the welded joints increased in the order of LW, LW-Ti-A, and LW-Ti-B, which indicates that adding Ti to the FZ and HAZ separately had an obvious strengthening effect. The fracture positions of the joints were primarily affected by the Ti alloying scheme. The LW joints are always fractured at the FZ, showing brittle intergranular fractures; the LW-Ti-A joints fractured at the BM or the HAZ near the FZ; and the LW-Ti-B joints fractured at the BM far from the FZ, exhibiting ductile fracture. Adding Ti to the FZ can induced a solid-solution strengthening effect, which refined the grain size in the FZ by approximately 30–40% and reduced the amount of Mo oxide on the grain boundaries in the FZ, thus improving the joint strength. Presetting a Ti foil on the overlapping interface in the HAZ realized metallurgical bonding between the Mo tube and Mo end plug in the HAZ of the laser-welded joints, enlarge the bearing area, and improve the joint strength. And a new metallurgical bond zone is formed on the overlapping interface in the HAZ during the high-temperature tensile tests of the welded joints, which further improve the joint strength.

A Comparison Study on the Microstructure, Mechanical Features, and Tribological Characteristics of TiN Coatings on Ti6Al4V Using Different Deposition Techniques

Titanium alloys are considered lightweight alloys and are widely applied across various industries. However, their low hardness, poor wear resistance, and limited oxidation resistance restrict their prospects for wider application. In this paper, nitride coatings were prepared using three preparation processes, namely laser surface nitriding (LSN), physical vapor deposition (PVD), and plasma ion implantation (PII). Their microstructure, microhardness, tribological behavior, and high-temperature oxidation characteristics were compared. The experimental results revealed that nitrided coatings were successfully prepared using the three methods. However, a comparison of these data shows that the LSN coating exhibited superior comprehensive performance. It achieved the maximum thickness within the shortest preparation time: the thickness was about 280 μm and the deposition rate of the LSN method was 2250 and 90,000 times higher than those of the PVD and PII methods. Nitrides have high hardness, but the carrying capacity could be attributed to the thickness of the coatings: the PVD coating could withstand a force of 500 g, while the PII coating only withstood a force of less than 25 g. In addition, as hardness is the most important factor for excellent wear resistance, the average volumetric wear rate of the LSN and PVD coatings was about 9 × 10−6 mm3/m·N, and their relative wear resistance was 49.2 times that of Ti6Al4V. Meanwhile, the excellent bond between the LSN coating and the substrate was evidenced by a high-temperature oxidation test during a rapid heating–cooling cycle.

Mechanical, electrochemical corrosion, and high-temperature oxidation properties of stir-cast and heat-treated AZ80 magnesium alloy

This study aims to produce a stir-cast AZ80 magnesium alloy and to correlate the phases and microstructure of the as-cast, T4, and T6 conditions with the alloy's mechanical, corrosion, and oxidation properties. Microstructure was analysed using Field Emission Scanning Electron Microscopy (FE-SEM) with Energy Dispersive Spectroscopy (EDS), Electron Backscatter Diffraction (EBSD), and High-Resolution Transmission Electron Microscopy (HRTEM), and X-ray diffraction (XRD) technique was employed to examine at the alloy’s phases. A Vickers microhardness, tensile, and impact test specimens were meticulously prepared according to ASTM specifications. The electrochemical corrosion was tested in 0.6 M NaCl and 0.05 H2SO4, simulating the salty seawater and low-sulphur air environments. Based on the eutectic temperature of the Mg-Al alloy system, which is 437 ℃, the high-temperature oxidation test was carried out at 400 ℃, 410 ℃, and 420 ℃. Microstructural study confirms that both T4 and T6 alloys undergo grain coarsening with a grain size of 72.64 µm, and the orientation of the grains shifted from the pyramidal plane (2−1-10) to the basal plane (0001). The TEM investigation helps pinpoint the GP zone's genesis in T4 heat-treated AZ80. T4 AZ80 has a maximum ultimate tensile strength of 306 MPa and a ductility of 29.77% because of the dispersion-strengthening effect. The T6 AZ80, on the other hand, has a minimum corrosion rate of 0.158 mm/year in NaCl solution and an oxidation rate constant of 4.19 mg2.cm−4h−1 at 420 ⁰C. Notably, the T6 AZ80 shows significant peaks of Mg2Al3, and the as-cast shows more peaks of Mg17Al12. Magnesium alloy AZ80 is significantly affected by intermetallic phases like Mg17Al12 and Mg2Al3. The Mg2Al3 phase shows the latter tendency to resist corrosion and oxidation.

Thermal Deformation Behavior and Microstructural Evolution of Multicomponent Mg-Li-Zn-Al-Y Alloys under Hot Compression.

High-temperature compression tests on Mg-11.5Li-2.5Zn-0.35Al-0.3Y (in wt.%) were carried out on a Gleeble-3500 thermal simulator. Flow stress and microstructural evolution were analyzed at different temperatures (T = 473 K, 523 K, 573 K, and 623 K) and strain rates (ε˙ = 1 s-1, 0.1 s-1, 0.01 s-1, and 0.001 s-1). On this basis, the constitutive model of the alloy was established using the Arrhenius-type constitutive model, and the thermal processing map of the alloy was drawn based on the DMM (dynamic material modeling) theory. The experimental results show that the flow stress of the Mg-11.5Li-2.5Zn-0.35Al-0.3Y alloy decreases with an increase in temperature and a decrease in strain rate. The grain size increases uniformly with the increase in temperature, while a sudden increase occurs with the decrease in strain rate. The predicted value of the model is compared with the experimental value to verify the correctness of the model, and the correlation coefficient, R = 0.9690, was calculated, which further proves the applicability of the model to the Mg-11.5Li-2.5Zn-0.35Al-0.3Y alloy. This alloy can be safely plastic-deformed 473 K~623 K and 0.001 s-1~1 s-1.

Wettability, reactivity, and interface structure in Mg/Ni system

The sessile drop method was applied to the experimental investigation of the wetting and spreading behaviors of liquid Mg drops on pure Ni substrates. For comparison, the experiments were performed in two variants: (1) using the Capillary Purification (CP) procedure, which allows the non-contact heating and squeezing of a pure oxide-free Mg drop; (2) by classical Contact Heating (CH) procedure. The high-temperature tests were performed under isothermal conditions (CP: 760 °C for 30 s; CH: 715 °C for 300 s) using Ar + 5 wt% H2 atmosphere. During the sessile drop tests, images of the Mg/Ni couples were recorded by CCD cameras (57 fps), which were then applied to calculate the contact angles of metal/substrate couples. Scanning and transmission electron microscopy analyses, both coupled with energy-dispersive X-ray spectroscopy, were used for detailed structural characterization of the solidified couples.It was found that an oxide-free Mg drop obtained by the CP procedure showed a wetting phenomenon on the Ni substrate (an average contact angle θ < 90° in < 1 s), followed by fast spreading and good wetting over the Ni substrate (θ(CP) ∼ 20° in 5 s) to form a final contact angle of θf(CP) ∼ 18°. In contrast, a different wetting behavior was observed for the CH procedure, where the unavoidable primary oxide film on the Mg surface blocked the spreading of liquid Mg showing apparently non-wetting behavior after 300 s contact at the test temperature.However, in both cases, the deep craters formed in the Ni substrates under the Mg drops and significant change in the structure of initially pure Mg drops to Mg-Ni alloys suggest a strong dissolution of Ni in liquid Mg and apparent values of the final contact angles measured for the Mg/Ni system.

Thermoregulatory consequences of growing up during a heatwave or a cold snap in Japanese quail.

Changes in environmental temperature during development can affect growth, metabolism and temperature tolerance of the offspring. We know little about whether such changes remain to adulthood, which is important to understand the links between climate change, development and fitness. We investigated whether phenotypic consequences of the thermal environment in early life remained in adulthood in two studies on Japanese quail (Coturnix japonica). Birds were raised under simulated heatwave, cold snap or control conditions, from hatching until halfway through the growth period, and then in common garden conditions until reproductively mature. We measured biometric and thermoregulatory [metabolic heat production (MHP), evaporative water and heat loss (EWL, EHL) and body temperature] responses to variation in submaximal air temperature at the end of the thermal acclimation period and in adulthood. Warm birds had lower MHP than control birds at the end of the thermal acclimation period and, in the warmest temperature studied (40°C), also had higher evaporative cooling capacity compared with controls. No analogous responses were recorded in cold birds, although they had higher EWL than controls in all but the highest test temperature. None of the effects found at the end of the heatwave or cold snap period remained until adulthood. This implies that chicks exposed to higher temperatures could be more prepared to counter heat stress as juveniles but that they do not enjoy any advantages of such developmental conditions when facing high temperatures as adults. Conversely, cold temperature does not seem to confer any priming effects in adolescence.

The Effect of Laser-Cladded Co6, T400, and Ni-Based 30WC Coatings on the Wear Resistance of H13 Steel

To enhance the wear resistance of H13 steel (4Cr5MoSiV1), Co6, T400, and Ni-based 30WC coatings were applied to the surface of H13 steel using laser cladding technology. The microstructures and phase compositions of the three coating types were analyzed using SEM and XRD methods. The high-temperature friction and wear performance of the three coated samples and H13 steel were measured through high-temperature friction wear tests, and the friction wear types of the four samples were analyzed. A comparative analysis of experimental data led to the following conclusions: (1) Among the four samples, the Ni-based 30WC-coated sample exhibited the best self-lubricating properties. (2) The average wear area of H13 steel was 0.059 mm2, and the wear volume was 0.29 mm3; the average wear area of Co6-coated samples was 0.050 mm2, and the wear volume was 0.25 mm3; the average wear area of T400-coated samples was 0.002 mm2, and the wear volume was 0.01 mm3; and the average wear area of the Ni-based 30WC-coated sample was 0.035 mm2, and the wear volume was 0.17 mm3. In terms of wear resistance, the ranking from highest to lowest was: T400-coated sample &gt; Ni-based 30WC-coated sample &gt; Co6-coated sample &gt; H13 steel. (3) Based on the classification of friction wear types, H13 steel primarily exhibited adhesive wear and oxidized wear; the Co6- and T400-coated samples primarily showed adhesive wear, abrasive wear and oxidized wear; and the Ni-based 30WC-coated sample mainly exhibited abrasive wear and oxidized wear.

High-temperature tolerant TaOX/HfO2 self-rectifying memristor array with robust retention and ultra-low switching energy

Due to the heat generation during operations in high-density three-dimensional (3D) integrated chips, a high-temperature tolerant and high-performance self-rectifying memristor (SRM) is a promising candidate for 3D integration. Here, we investigated the high-temperature characteristics of Ta/TaOX/HfO2/Pt SRMs with a 250 nm feature size in an 8 × 8 crossbar array (CBA). The SRMs exhibit high uniformity and can be operated repeatedly at Set (4 V/2 μs) and Reset (-2 V/1 μs) pulses for more than 104 cycles resulting in ultra-low switching energy (5.86 aJ for Set and 77.2 aJ for Reset). High yield of the array indicates the reliable preparation processes. Remarkably, the CBA is capable of stably resistive switching at high temperatures from 300 to 475 K. At 300 K, the SRM shows large nonlinearity (NL, ∼1.4 × 104) and rectification ratio (RR, ∼8.8 × 103) as well as high scalability (330 Mbit); at 475 K, the NL and RR of the SRM can still maintain above 400, and the scalability still reaches 71 Kbit. Moreover, our SRM passed a high-temperature retention test of over 5 × 104 s at 438 K. Segmented fittings of the I–V curves of the SRM at different temperatures were performed, concluding that large NL and RR attributed to the Schottky barriers at TaOX/HfO2 and Pt/HfO2 interfaces, respectively. Our work furnishes a feasible solution for high-density 3D integrated memristors in high-temperature application scenarios represented by automotive-grade chips.

Carbon nanofibers/liquid metal composites for high temperature laser ultrasound

As the demand for clean energy becomes greater worldwide, there will also be an increasing demand for next generation nuclear power plants that incorporate advanced sensors and monitoring equipment. A major challenge posed by nuclear power plants is that, during normal operation, the reactor compartment is subjected to high operating temperatures and radiation flux. Diagnostic sensors monitoring such structures are also subject to temperatures reaching hundreds of degrees Celsius, which puts them at risk for heat degradation. In this work, the ability of carbon nanofibers to work in conjunction with a liquid metal as a photoacoustic transmitter was demonstrated at high temperatures. Fields metal, a Bi-In-Sn eutectic, and gallium are compared as acoustic mediums. Fields metal was shown experimentally to have superior performance over gallium and other reference cases. Under stimulation from a low fluence 6 ns pulse laser at 6 mJ/cm2 with 532 nm green light, the Fields metal transducer transmitted a 200 kHz longitudinal wave with amplitude >5.5 times that generated by a gallium transducer at 300 °C. Each high temperature test was conducted from a hot to cold progression, beginning as high as 300 °C, and then cooling down to 100 °C. Each test shows increasing signal amplitude of the liquid metal transducers as temperature decreases. Carbon nanofibers show a strong improvement over previously used candle-soot nanoparticles in both their ability to produce strong acoustic signals and absorb higher laser fluences up to 12 mJ/cm2.

Effect of geometry on the evolution of DLOFC transients in high temperature helium loop

Generation IV high-temperature gas-cooled reactors (HTGR) are designed to exhibit passive safety under all off-normal circumstances. One such scenario, known as depressurized loss of forced circulation (DLOFC), occurs after a break in the inlet/outlet header, allowing helium to leak from the reactor. Upon depressurization, the onset of natural circulation (ONC) can occur causing bulk air ingress leading to the oxidation and degradation of core components. The Transformational Challenge Reactor (TCR) has similar features to those of an HTGR, but the primary difference is the use of a more complex, additively manufactured (AM) fuel geometry. The more compact, additively manufactured, ceramic fuel elements can be conveniently produced with optimally configured channels that suppress the air ingress progress and improve thermofluidic performance. DLOFC and air ingress are experimentally studied in a scaled HTGR flow test setup. The experiments use an AM test element embedded with a distributed temperature sensor as well as a test geometry comprised of spherical pebble bed elements. With the test geometries aligned within a lowercase h-shaped tube flow setup, further data was obtained to improve the understanding of DLOFC. The thermal transient and air ingress data gathered for both test geometries are compared. The results show that the AM part delayed ONC as compared to the pebble bed test piece at higher temperatures. The distributed temperature sensor shows intra-leg circulation at higher temperature tests.

An early detection indicator of combustion instability for an industrial gas turbine combustor

Detection of combustion instability is crucial for the safety and reliability of gas turbines. In this paper, the recurrence quantification analysis (RQA) and multi-fractal analysis (MFA) methods are applied to investigate the transition process from combustion noise to combustion instability in an industrial-scale combustor. Based on the dynamic pressure (DP) obtained from high pressure and high temperature tests, a novel method is proposed to construct early detection indicators (EDI) of combustion instability. The method is mainly based on the three-dimensional map of the recurrence rate, Hurst exponent, and root mean square ratio. A regression method and SVM are applied to define the classification boundary. For three test cases, the results showed that the proposed EDI can effectively detect the onset of combustion instability. Compared to the conventional method based on the root mean square levels of dynamic pressure, the EDI has capability to forecast the onset of combustion instability approximately a few hundred milliseconds in advance.

Optical fiber high-temperature pressure sensor with weak temperature sensitivity

In aerospace, petrochemical, gas turbines and other high-temperature environments, pressure measurement of equipment has always been a challenge to be solved. The electrical high temperature pressure sensor has the problem of component failure in high temperature environment, and it is difficult to use in the high temperature environment for a long time. The detection device of the optical fiber sensor does not include electrical components, so it has the advantages of high working temperature, high measurement accuracy, anti-electromagnetic interference and so on. In order to use a sensor to measure pressure in high temperature environment, a temperature-weakly sensitive optical fiber micro-electro-mechanical system (MEMS) pressure sensing technology is proposed. The technique uses extrisic Fabry-Pérot interference (EFPI) model. It uses the MEMS pressure chip to passively modulate the optical signal of the interference, and then realizes the pressure signal measurement. Among them, MEMS pressure sensitive chip is the core component of the sensor. The MEMS pressure sensitive chip adopts the design method of all solid state vacuum absolute pressure. Change in environmental pressure will deform the membrane. This phenomenon can cause change in the cavity of the EFPI cavity. Therefore, stress information can be obtained by measuring changes in EFPI cavity. The thermal stress and temperature parasitical response introduced by thermal expansion of the material are calculated by simulation. The influence of temperature signal on chip displacement is analyzed by the above results. On this basis, a prototype of high temperature pressure sensor is developed by combining the sub-micron white light interference response technology and low thermal stress packaging technology. In order to test the ability of the sensor to implement actual measurement, this paper carry out the pressure test and high temperature test respectively. When the pressure changes from 0 kPa to 100 kPa, the spectral intensity of the sensor output has a linear relationship with the pressure. During the temperature changing from 20–400 ℃, the spectral intensity of the sensor output does not change significantly. The experimental test results show that the pressure measurement of 0–100 kPa can be satisfied in the range of 20–400 ℃, and the measurement error introduced by temperature change is less than 4%. Therefore, the fiber pressure sensor can be used to measure the pressure in high temperature environment.

Additively manufactured tantalum cathode for FEBIAD type ion sources: production, geometric measurements, and high temperature test

The Laser Powder Bed Fusion (LPBF) is an Additive Manufacturing (AM) technology suitable to produce almost free-form metallic components. At Legnaro National Laboratories (LNL) of the Italian National Institute for Nuclear Physics (INFN), the LPBF process was recently used to produce parts of the Forced Electron Beam Induced Arc Discharge (FEBIAD) ion source for the SPES Isotope Separation On-Line (ISOL) facility. In this work are presented the feasibility assessment and production steps of tantalum cathodes produced via AM; in addition, the results concerning both the dimensional-geometrical measurements and the preliminary high-temperature test are reported.

Failure Analysis on Abnormal Cracking of Flip-Chip Au Bumps During the High Temperature and Humidity Testing

Failure Analysis on Abnormal Cracking of Flip-Chip Au Bumps During the High Temperature and Humidity Testing

About the influence of high temperature or fire testing conditions on the tensile behavior of carbon reinforced poly phenylene sulfide laminates

This study aims to investigate the thermo-mechanical coupling in carbon fibers reinforced Poly Phenylene Sulfide (PPS) laminates subjected to critical temperature conditions. In order to dissociate the physical phenomena (degradation/decomposition on the one hand and deformation/damage mechanisms on the other hand) at play in quasi-isotropic laminates (fiber-dominated mechanical behavior), homogenous and fire testing conditions (heterogenous) were considered with or without mechanical loading. X-Ray tomographic and fractographic analyses were conducted to identify the role played by porosities formation (resulting from thermally induced deformations and damages) on the structural bearing capabilities of C/PPS laminates to be used in high-temperature environments. Under high temperature conditions (homogenous temperature distribution), the retention of tensile properties is not well preserved as the axial stiffness and strength decrease of 50% and 75%, respectively. Under fire conditions (heterogenous temperature distribution), the degradation of tensile properties is more dramatic with an 80% decrease.