Microstructural Analysis Research Articles

Analysis of Microstructure, Cell Wall Polysaccharides, and Candidate Cell Wall-related Genes in Clingstone-type and Freestone-type Stony Hard Peaches during Ripening

Stony hard (SH) peach (Prunus persica) fruits produce no ethylene and clingstone-type SH peaches have a crispy flesh texture; however, freestone-type SH peach fruits ripen to a soft, mealy state. During this study, we compared and analyzed changes in the microstructure, cell wall polysaccharides, and candidate cell wall-related genes of freestone-type SH ‘Zhongtao 14’ (‘CP14’), ‘Zhongtao White Jade 2’ (‘CPWJ2’), clingstone-type SH ‘Zhongtao 13’ (‘CP13’), and ‘Zhongtao 9’ (‘CP9’) during fruit ripening. The parenchyma cells of mealy freestone-type SH peaches became detached, were single, dried, and irregularly arranged, and remained intact in comparison with the nonmealy clingstone-type SH peaches. Methyl-esterified homogalacturonan was strongly immunolabeled in the cell wall of clingstone SH peaches; however, nonmethylated homogalacturonan was weakly immunolabeled in freestone SH peaches. A transcriptome analysis was performed to investigate the molecular mechanism of the mealiness process. A principal component analysis indicated that ‘CP14’ S4 III (mealy) could be distinguished from the samples of ‘CP13’ (S4 I, S4 II, S4 III) and ‘CP14’ (S4 I, S4 II). The highly coexpressed gene modules linked with firmness were found using a weighted gene coexpression network analysis; 189 upregulated genes and 817 downregulated genes were identified. Six upregulated cell wall-related genes (PpPG1, PpPG2, PpAGP1, PpAGP2, PpEXT1, and PpEXP1) and one downregulated cell wall-related gene (PpXET2) were involved in the mealiness process during freestone-type SH fruit ripening. These findings will improve our understanding of the relationship between clingstone, freestone, and stony hard fruits and lay the foundation for further exploration of the mechanisms underlying the softening of peach fruits.

Comparative study of Cr-coating and Zr-lining method on inner surface of HT9 cladding to mitigate Fuel-Cladding chemical interaction

A comparative study was conducted between electroplated Cr coatings and Zr linings as inner-surface barriers to mitigate chemical interactions in metallic nuclear fuel claddings. The comparison involved microstructural analysis and micro-CT examination to analyze their inner-surface morphology, along with an evaluation of their mechanical properties. Furthermore, diffusion couple tests were conducted to determine the fuel-cladding chemical interaction (FCCI) resistance. Both barrier processes demonstrated superior FCCI resistance compared with untreated HT9; however, several limitations were identified. Although potential improvements were expected for the Cr-coating process through modifications of the applied pulsed current waveforms, the Zr-lining process presented major process-related dilemmas that were challenging to overcome.

TRIBOLOGICAL TESTS OF ACRYLIC TEETH FOR REMOVABLE DENTURES

The functionality of removable dentures is ensured by proper diagnostics and clinical modeling. Noless important are the structural conditions and the biotribological and biomechanical context, whichdetermine the wear resistance in the contact of opposing teeth and the contact of the denture plate with thestomatognathic system. The aim of the study is to evaluate acrylic teeth used in prosthetic reconstructionsbased on microstructural, micromechanical and tribological tests. Samples for testing were taken from teethfor removable dentures made by various manufacturers. Microstructural analyses were performed using anoptical microscope and a scanning microscope. Microhardness and elasticity coefficient measurements wereperformed on the NHT device. Tribological tests were performed on a Roxana Machine Works tester using afriction node: ball – 3 discs made of the tested material. The conducted research allowed for the evaluation ofthe structural quality of acrylic teeth and the determination of the tribological interaction resulting from thecontact of synthetic and natural teeth in the presence of artificial saliva.

Experimental Investigation into Strength Properties of Ribbed Mild Steel Reinforcing Bars (RMSRBs) Produced by Local Companies in Ghana

The construction of high-rise buildings has increased the production and demand of ribbed mild steel reinforcing bars (RMSRBs) in Ghana. This study aimed at investigating the strength properties of RMSRBs manufactured in Ghana from scrap metals. Three steel-producing companies were considered for this study. A total of 90 samples of 12, 16, and 20mm diameters with lengths of 500, 50, and 20mm were used for the study. The prepared specimens were subjected to tensile strength test, chemical composition analysis, micro-hardness test, and microstructure analysis. The results indicate that the average tensile strength of between 576.00 and 768.40N/mm2 were above the minimum tensile strength of 250N/mm2 recommended by ASTM E8/E8M-16a. The carbon equivalent values (CEVs) of between 0.287 and 0.333% obtained were almost within the range of 0.3 to 0.55% recommended by ASTM A706/A706M-09b. It was also identified that the average Vickers hardness values of between 255.76 and 295.38HV were acceptable. The microstructural images showed good distribution of the pearlite and ferrite of the core. One Way ANOVA results indicated that the differences in the tensile strength values for 12mm (p-value ˂0.000) and 16mm (p-value =0.001) were statistically significant, however, the 20mm (p-value =0.138) was not statistically significant. The study, therefore, concludes that the strength properties of the 12, 16, and 20mm diameters of the RMSRBs produced by the three different companies in Ghana meet the standard requirements, and are recommended for use by contractors for the production of reinforced concrete.

Glass bonding of YAG/Nd:YAG and Sapphire/Nd:YAG windows

Transparent ceramic assemblies are of great interest and challenge for many optical applications. Lead silicate-based glass was successfully utilized to bond YAG/Nd:YAG and sapphire/Nd:YAG substrates at 850 °C in air. The glass's thermal characteristics and refractive index were measured and found to be comparable to those of YAG and sapphire. Microstructure and composition analysis of the glass bonding interface reveals no evidence of flaws or reaction products. The in-line transmission results of the YAG/Nd:YAG and sapphire/Nd:YAG assemblies are equivalent to those of the initial Nd:YAG ceramics throughout a wide wavelength range (450–1200 nm). The reported findings establish an efficient approach for future design and implementation of complex optical systems with enhanced optical and thermal properties.

Microstructural Evolution and Densification of Co-Based Alloy Powder by Spark Plasma Sintering for High-Hardness Applications

This work presents the densification of Co-based alloy powders by a spark plasma sintering process. The densification process was carried out at a temperature range of 800 °C to 1100 °C in order to obtain sintered coupons and study their microstructure and mechanical properties. The shrinkage behaviour of the sintered coupons was studied, and an optimal densification temperature was defined. The microstructural analysis showed a reduction in porosity with temperature increment along with the development of a fine microstructure comprised of cobalt-molybdenum-chromium-silicon-based intermetallic laves phases, which are dispersed in a softer cobalt-based alloy matrix. X-diffraction analysis showed that these crystalline phases were well-dispersed, with a lattice parameter corresponding to a hexagonal system. The obtained high Vickers hardness values were attributed to the preservation of a fine microstructure and to the precipitation of Co-Mo phases. Three-point bending tests were performed in order to identify the strain path concerning the densification of the sintered coupons.

Investigating the Impact of Friction Stir Processing on the Hydrogen Embrittlement in AA6082-T6 Heat-Treatable Aluminum Alloy

AbstractThis study investigates the impact of friction stir processing (FSP) on the hydrogen embrittlement (HE) in AA6082-T6 heat-treatable aluminum alloy. The effects of different number of FSP passes and different hydrogen cathodic charging (HCC) conditions on the material’s response to HE are examined through comprehensive mechanical testing, microhardness analysis, and microstructural characterization. The results revealed that FSP leads to a decrease in yield strength, ultimate tensile strength, and microhardness, accompanied by an increase in energy absorption. The introduction of hydrogen through HCC significantly reduces mechanical properties, particularly in non-FSPed specimens. Notably, specimens with 8 FSP passes exhibit an interesting behavior with a slight increase in energy absorption and microhardness values after HCC. Microstructural analysis shows that FSP refines the microstructure, resulting in enhanced resistance to hydrogen-induced blistering effects. These findings contribute to the understanding of hydrogen embrittlement in FSPed aluminum alloys, providing insights for developing surface-modified materials suited for hydrogen-rich applications. Graphical Abstract

Nondestructive Single-Atom-Thick Crystallographic Scanner via Sticky-Note-Like van der Waals Assembling-Disassembling.

Crystallographic characteristics, including grain boundaries and crystallographic orientation of each grain, are crucial in defining the properties of two-dimensional materials (2DMs). To date, local microstructure analysis of 2DMs, which requires destructive and complex processes, is primarily used to identify unknown 2DM specimens, hindering the subsequent use of characterized samples. Here, a nondestructive large-area 2D crystallographic analytical method through sticky-note-like van der Waals (vdW) assembling-disassembling is presented. By the vdW assembling of veiled polycrystalline graphene (PCG) with a single-atom-thick single-crystalline graphene filter (SCG-filter), detailed crystallographic information of each grain in PCGs is visualized through a 2D Raman signal scan, which relies on the interlayer twist angle. The scanned PCGs are seamlessly separated from the SCG-filter using vdW disassembling, preserving their original condition. The remaining SCG-filter is then reused for additional crystallographic scans of other PCGs. It is believed that the methods can pave the way for advances in the crystallographic analysis of single-atom-thick materials, offering huge implications for the applications of 2DMs.

Enhancement of Flexural Strength in Fiber–Cement Composites through Modification of Sisal Fiber with Natural Rubber Latex and Expanded Perlite

This study presents a novel approach in enhancing the flexural strength of sisal fiber cement composites by employing a dual coating technique with natural rubber latex and expanded perlite to the sisal fibers. The effects of different fiber content (0.25, 0.5, 0.75, 1, 1.25, and 1.5 wt%) and fiber length (1, 2, and 3 cm) on the physical and mechanical properties of sisal fiber cement were also studied. The physical properties, including bulk density and water absorption, were evaluated via the Archimedes method. Flexural strength was measured using the 3-point bending method, and microstructure was observed using a scanning electron microscope (SEM) and an optical microscope (OM). As the fiber content and length increase, the bulk density of the sisal fiber cement decreases. However, composites utilizing coated fibers consistently exhibit a higher bulk density than those utilizing uncoated fibers, attributed to enhanced adhesion and reduced porosity. The water absorption of sisal fiber cement increases with fiber content, but it is mitigated by the natural rubber latex coating, which prevents fiber–water absorption, and by expanded perlite, which reduces voids in the matrix. Composites containing coated fibers consistently exhibit superior flexural strength compared to those with uncoated fibers. The highest flexural strength values of 5.58 MPa were observed in composites utilizing 3 cm of coated fiber with 0.25 wt% fiber content. Microstructure analysis reveals a well-bonded interface in coated fibers, emphasizing the positive impact of coating on mechanical performance. The incorporation of coated sisal fibers effectively improves adhesion, water resistance, and flexural strength, offering sustainable and durable construction materials. The achieved results can serve as the guidelines for the development of a high-performance bio-based construction materials with improved durability and reduced environmental impact.

Ultraviolet‐Driven Photocatalytic Degradation of Rhodamine B Using Ag3PO4 Nanoparticles for Sustainable Catalysis

AbstractThe design and development of multifunctional nanomaterials holds the key to unlocking new possibilities in water treatment technologies due to the exceptional properties that emerge at the nanoscale. Here, we demonstrate the photocatalytic efficiency of silver orthophosphate in the UV region choosing Rhodamine B as the pollutant model. To begin with, a simple and scalable route was employed for the synthesis of silver orthophosphate nanoparticles. The cubic phase of the crystallized synthesized nanoparticles is revealed from powder X‐ray diffraction patterns and the optical absorbance exhibited onset of absorption at 522 nm in UV–visible spectrum. The microstructural analysis performed using scanning electron microscopy revealed the size of the particles to be in the range of 200–500 nm. The catalytic efficiency of the silver orthophosphate nanoparticles was assessed by following the kinetics of photocatalytic degradation and is observed to follow pseudo‐first order kinetics with the apparent rate constant  min−1. The findings underline the efficiency of silver orthophosphate nanoparticles as a sustainable catalyst in UV region for the photoremediation of water contaminated with organic pollutants.

Effect of Ru on the precipitation of the TCP phase from the γ-γʹ microstructural degradation analysis

This work investigates the effect of Ru on the precipitation of the topologically close-packed (TCP) phase from the γ-γʹ microstructural degradation analysis. The addition of Ru is found to delay the precipitation time of the TCP phase from 100 h to 1000 h after thermal exposure at 950 °C. The effect of Ru on the γ-γʹ microstructural degradation is also investigated. Adding Ru slightly decreases the coarsening rate of the γʹ size and promotes the reduction of the volume fraction of γʹ phase. The reduction of the volume fraction of γʹ phase causes the "inverse partitioning" effect and increases the solution limit of the TCP forming element in the matrix. These help inhibit the precipitation of the TCP phases in Ni-based single crystal superalloys during thermal exposure.

Characterization of flexural fatigue behaviour of additively manufactured (PBF–LB) gyroid structures

AbstractAdditive manufacturing (AM) holds remarkable potential for producing cellular materials with intricate structures and tailored mechanical properties. The study investigates the flexural fatigue behaviour of additively manufactured triply periodic minimal surface (TPMS) gyroid structures using laser powder bed fusion (PBF–LB) technique. The fatigue properties, especially the bending fatigue properties, of additively manufactured cellular structures are not well understood to date. The research aims to enhance understanding of bending fatigue in complex cellular geometries and assess the suitability of rotating bending tests. The PBF–LB process parameters were modified to study their impact on the specimen’s fatigue properties. The modified parameters led to increased surface roughness but significantly improved fatigue behaviour. This enhancement is attributed to a reduction in build defects, namely pores and finer grain size in thin-walled structures. The study also includes analysis of microstructure, hardness, surface roughness, and porosity of the specimens. The results indicate that optimizing process parameters for thin walled cellular structures can lead to substantial improvements in fatigue strength, at the expense of increased surface roughness. This finding offers practical insights for applications in which a rough surface finish may not be critical or even intentionally desired by the application. The research contributes to the understanding of additive manufacturing, cellular structures, and material testing, with potential implications for materials science and engineering applications.

Medium-Chain Triglycerides-Specific Appetite is Regulated by the β-oxidation of Medium-Chain Fatty Acids in the Liver.

Most studies on fat appetite have focused on long-chain triglycerides (LCTs) due to their obesogenic properties. Medium-chain triglycerides (MCTs), conversely, exhibit anti-obesogenic effects; however, the regulation of MCTs intake remains elusive. Here, we demonstrate that mice can distinguish between MCTs and LCTs, and the specific appetite for MCTs is governed by hepatic β-oxidation. We generated liver-specific medium-chain acyl-CoA dehydrogenase (MCAD)-deficient (MCADL-/-) mice and analyzed their preference for MCTs and LCTs solutions using glyceryl trioctanoate (C8-TG), glyceryl tridecanoate (C10-TG), corn oil, and lard oil in two-bottle choice tests conducted over 8 days. Additionally, we employed lick microstructure analyses to evaluate the palatability and appetite for MCTs and LCTs solutions. Finally, we measured the expression levels of genes associated with fat ingestion (Galanin, Qrfp, and Nmu) in the hypothalamus 2 h after oral gavage of fat. Compared to control mice, MCADL-/- mice exhibited a significantly reduced preference for MCTs solutions, with no alteration in the preference for LCTs. Lick analysis revealed that MCADL-/- mice displayed a significantly decreased appetite for MCTs solutions only, while the palatability of both MCTs and LCTs solutions remained unaffected. Hypothalamic Galanin expression in control mice was elevated by oral gavage of C8-TG but not by LCTs, and this response was abrogated in MCADL-/- mice. In summary, our data suggest that hepatic β-oxidation is required for MCTs-specific appetite but not for LCTs-specific appetite. The induction of hypothalamic galanin upon MCTs ingestion, dependent on hepatic beta-oxidation, could be involved in the regulation of MCTs-specific appetite.

An adapted approach for solidification crack elimination in Al7075 TIG welding

Abstract Solidification cracking is a long-standing issue in fusion welding of high-strength aluminum alloys like Al7075, imposing limitations on their aerospace and automotive applications. The current study introduces a novel adapted approach in solidification crack elimination by incorporating TiC nanoparticles into the fusion zone using a filler paste as an easier to fabricate alternative to filler metals investigated so far. To assess the weldability of the proposed method, 3-mm thick Al7075 sheets were TIG welded (i) autogenously without any TiC nanoparticles (autogenous), (ii) heterogeneously using 1 vol.% TiC-nanoparticle enhanced Al7075 filler metal (heterogeneous filler metal), and (iii) heterogeneously using an in-house fabricated Al7075 paste containing 1 vol.% TiC nanoparticles (heterogeneous filler paste). Macroscopic analysis of weld specimens proved that both heterogeneous welding approaches effectively eliminated solidification cracks. This was confirmed by Houldcroft solidification susceptibility index deduction tests that demonstrated a strong reduction in solidification crack susceptibly in all heterogeneous joints as compared to the autogenous joint. Microstructural analysis confirmed the transformation from columnar to equiaxed grain morphology in the fusion zone as crucial factor in crack elimination. Overall, the proposed filler paste method represents a highly cost-efficient approach for eliminating solidification cracks in TIG joining of difficult to weld aluminium alloys.

Impact of Heat Treatment and Building Direction on Tensile Properties and Fracture Mechanism of Inconel 718 Produced by SLM Process

In the selective laser melting (SLM) additive manufacturing process of Inconel 718, the emergence of Laves and δ precipitate phases in the γ matrix during or after heat treatment is a critical consideration. This study comprehensively assesses the microstructures and mechanical properties of Inconel 718 alloy produced through SLM under varied conditions: as-built (AB), homogenization + solution + aging (HSA), homogenization + aging (HA), and solution + aging (SA). Additionally, the impact of building orientation, whether horizontal (H) or vertical (V), is investigated. The AB specimens oriented horizontally display a columnar melt pool structure, with dimensions roughly between 300 and 400 μm. In contrast, the AB specimens aligned vertically show an elongated river-like structure of melt pools, with their sizes approximately at 250 μm. From the detailed microstructural analysis, the findings reveal that the as-built specimens lack γ′ and γ″ precipitates in their microstructure. Conversely, in heat-treated specimens, both the γ′ and γ″ phases are evident. Notably, Inconel 718 alloy specimens subjected to SLM fabrication and SA heat treatment demonstrate optimal mechanical performance. Notably, SA exhibits an average hardness of 476 HV for the horizontal specimen, which is 51.1% higher than that of AB specimens. The morphology and distribution of the δ phase in the γ matrix emerge as decisive factors influencing high-temperature performance. In SA specimens, the dissolution of brittle Laves phases occurs, and the presence of the δ phase at the grain boundary imparts superior properties during high-temperature tensile testing, including excellent yield and ultimate tensile strength. The presence of the granular-δ phase in the SA specimens resulted in a tensile strength of 1422 MPa and a yield strength of 1236 MPa, which are the highest values among all the specimens. SA has a tensile strength of 1120 MPa and a yield strength of 974 MPa at 650 °C.

Effect of bonding time, composition of interlayer and post bond heat treatment on TLP joints of Inconel 718 superalloy

The investigation aimed to explore the relationship between the microstructure and mechanical properties of transient liquid phase‐bonded joints of Inconel 718 (IN718) nickel‐based superalloy, utilizing BNi‐1 and BNi‐2 interlayers with a thickness of 50 µm, produced at 1150 °C for varying durations. Microstructural analysis, facilitated by SEM, and phase analysis, utilizing EDS, revealed a diverse range of microstructures, including continuous eutectic intermetallic phases and eutectic‐free configurations under different bonding conditions. Additionally, the interfacial diffusion of IN718/BNi‐2 was simulated by molecular dynamics. Notably, higher mass fractions of Cr in the interlayer were found to prolong the time of isothermal solidification. The use of BNi‐2 interlayers, 50 µm in thickness, resulted in joints achieving isothermal solidification within a remarkably brief 10 mins, a significantly shorter duration compared to previous studies. Mechanical tests, encompassing microhardness and uniaxial tensile experiments, were carried out on all samples. The microhardness of the Isothermally Solidified Zone (ISZ) decreased with increasing bonding time. The tensile strength of bonded joints increased with extended bonding time before isothermal solidification completion, followed by a subsequent decline. The highest tensile strength (893.3 MPa) was observed in joints using BNi‐2 interlayer after applying post bond heat treatment (PBHT), representing approximately 88.5% of the base metal tensile strength.This article is protected by copyright. All rights reserved.

Influence of Curing Temperature on the Performance of Calcined Coal Gangue–Limestone Blended Cements

The utilization of calcined coal gangue (CCG) and limestone for the preparation of blended cement is an efficient approach to address the issue of coal gangue disposal. However, the compressive strength development of blended cement is slow, particularly at high substitution levels of CCG. Therefore, this study aimed to promote the hydration and mechanical properties of the calcined coal gangue–limestone blended cements by increasing the curing temperature. In this study, the samples were cured at two different temperatures, namely 20 and 40 °C. The four groups of samples contained 15 wt.%, 30 wt.%, 45 wt.% and 60 wt.% cement substitutions using CCG and limestone (2:1 mass ratio). The compressive strength, hydration and microstructure were investigated at the ages of 1 to 28 d. X-ray diffraction (XRD) and thermogravimetry (TG) were used to study the hydration behavior of samples. Mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) were used to determine the microstructure of the samples. The results indicate that an increase in curing temperature significantly promotes the compressive strength of the calcined coal gangue–limestone blended cements from 1 to 28 d. The microstructural analysis indicates that increasing the curing temperature not only promotes cement hydration but also facilitates the reaction of CCG, which precipitated more hydrates such as C-A-S-H gel, Hc and Mc. These hydrates are conducive to refining the pore structures and densifying the microstructure, which sufficiently explains the enhanced compressive strength of the calcined coal gangue–limestone blended cements.

Effect of Calcium Addition on the Aluminum Alloy A201 Foam

To study the effect of calcium on the porosity, sphericity, and microstructure of Al–Cu foams, a gradient calcium content (0.5, 1.0, 1.5, and 2.0 wt%) is added into aluminum A201 alloy (Al–Cu alloy) for the cellular aluminum foam preparation via the melt foaming method (TiH2 is used as a bubbling agent). Thereafter, the porosity of the prepared Al foams and their pore size are found to increase, and the sphericity of pores tends to approach to unit with calcium addition. This phenomenon is then explained through the modified thermophysical properties (i.e., surface tension and viscosity) of A201 alloy melts caused by the calcium addition. After the microstructure analysis, a bunch of secondary phases in the A201 + Ca alloy foams, e.g., CalAl2Si2, Al2Cu, and Al20CaTi2 as well as an eutectic phase with a great copper content Al8CaCu4 are detected by means of scanning electron microscopy/energy‐dispersive X‐Ray spectroscopy and X‐Ray diffraction analysis.

Fatigue Behavior and Fracture Surface Analysis of Corroded High-Strength Bridge Cable Wires

Bridge cable wires suffer from alternating stress and environmental erosion, leading to premature failure prior to its design life. This paper investigates the fatigue and mechanical behaviors of corroded bridge cable wires with a zinc–aluminum (Zn-Al) alloy coating. Based on the salt spray corrosion test and microstructure analysis, the anti-corrosion resistance and corrosion appearance characteristics of the Zn-Al alloy coating and galvanized coating were investigated. The Zn-Al alloy coating was superior in resistance to corrosion fatigue for the improvement in toughness and the generation of anti-corrosion Zn-Al and Fe-Zn-Al phases. Equations of the accelerated corrosion depth of the steel wires had been regressed to roughly estimate the corrosion life of the Zn-Al alloy coating, which can reach 29.1 years with a thickness of 70 μm. The fatigue and mechanical properties of the bare wires after the salt spray test were further studied based on tensile tests and fatigue tests. The fatigue properties of the bridge cable wire would decrease with the corrosion degree due to the deterioration and embrittlement of materials, where ductility characterized by the elongation rate was the most affected. Fracture surfaces of the wires were captured and analyzed based on a method for recognizing graphical contours. Insufficient fatigue life may occur in the steel wires after corrosion and increase with the degree of corrosion. The pit depth logarithmically weakened the fatigue life of steel wires for the weakening of fatigue toughness and the bearing area. The flat fracture was more common with a single fatigue source, while multiple fatigue sources led to step-like fractures for the generation of multiple dispersed crack propagation regions. Corrosion fatigue was more sensitive to the existence of fatigue sources than the reduction. Multiple initiation sources significantly reduced the fatigue life due to the cracking facilitation of the joint effect of multiple pits. The electrochemical reactions of corrosion can lead to material embrittlement and a reducing effect on the fracture toughness of the steel wires.

Enhancing Mechanical Characteristics of PETG Carbon Fiber Composite through Various Shell Thickness in FDM Processing

The utilization of PETG (Polyethylene Terephthalate Glycol) carbon fiber composites in Fused Deposition Modelling (FDM) processes has gained significant attention due to their enhanced mechanical properties compared to traditional PETG filaments. This study focuses on investigating the impact of varying shell thickness on the mechanical characteristics of PETG carbon fiber composites fabricated through FDM. The objective is to optimize the shell thickness to achieve superior mechanical performance while maintaining printing efficiency. A series of PETG carbon fiber composites with different shell thicknesses were manufactured using an FDM 3D printer. Mechanical tests, including tensile strength, flexural strength, and impact resistance, were conducted to evaluate the performance of the fabricated specimens. Additionally, micro-structural analysis was performed to understand the influence of shell thickness on the interfacial bonding between PETG matrix and carbon fibers. Preliminary results indicate that increasing shell thickness positively affects the mechanical properties of PETG carbon fiber composites. Tensile and flexural strength show a noticeable improvement with an increase in shell thickness, attributed to enhanced interlayer adhesion and improved load-bearing.