{"title":"Achieving ultra-high strength in TiB/metastable-β composites via short-process technology","authors":"","doi":"10.1016/j.compositesa.2024.108522","DOIUrl":"10.1016/j.compositesa.2024.108522","url":null,"abstract":"<div><div>Lightweight titanium alloys with ultra-high strength and reasonable ductility are desirable for aerospace applications. However, titanium alloys typically require cumbersome heat treatment to achieve excellent mechanical properties. Here, ultra-high strength Ti-55531-based composites were fabricated by introducing TiB whiskers using a short process, i.e. melting and isothermal forging. The microstructure evolution during isothermal forging was investigated, TiB whiskers would promote the discontinuous dynamic recrystallization and impede abnormal grain growth, resulting in significant β grain refinement, equiaxialization, and crystal orientation randomization. In addition, uniformly distributed nano-scaled α<sub>s</sub> lamellae were formed. 2.5 vol% TiB/Ti-55531 achieved a superior strength-plasticity synergy with the ultra-high strength of 1525 ± 4 MPa and elongation of 6.4 %±0.2 %, which were 9.2 % and 12.3 % higher than that of Ti-55531, respectively. The strengthening mechanisms were thoroughly analyzed, providing further insight to simplify the preparation and advance the application of ultra-high strength TMCs via short-process technology.</div></div>","PeriodicalId":282,"journal":{"name":"Composites Part A: Applied Science and Manufacturing","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Insert-injection moulding and post-thermal treatment of hybrid continuous and discontinuous glass-fibre-reinforced polyamide composite products","authors":"","doi":"10.1016/j.compositesa.2024.108534","DOIUrl":"10.1016/j.compositesa.2024.108534","url":null,"abstract":"<div><div>Insert-injection moulding enables direct interfacial bonding of hybrid continuous and discontinuous fibre-reinforced thermoplastic products and simultaneously influences dimension stability and mechanical performance. This study investigates the insert-injection moulding of short-glass-fibre-reinforced polyamide 6 (SGF-PA6) bonded with 8 wt% unidirectional continuous-glass-fibre-reinforced polyamide 6 (CGF-PA6), focusing on the dimensional and mechanical properties of the hybrid CGF-SGF-PA6 products, which are essential for engineering applications. Orthogonal experiments revealed that injection melt temperature and pack pressure significantly impact warping deformation and bending properties. The study found strong correlations between dimensional stability and mechanical strength, with interfacial bonding influencing mechanical strength only. Optimised injection moulding reduced warpage to below 0.1 mm, while increasing bending strength and modulus to 400 MPa and 10 GPa, respectively. Post-thermal treatment further enhanced mechanical properties but led to increased warpage. These findings highlight an integrative control strategy for dimensional and mechanical properties of insert-injection moulded hybrid continuous and discontinuous fibre-reinforced thermoplastic products.</div></div>","PeriodicalId":282,"journal":{"name":"Composites Part A: Applied Science and Manufacturing","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Freeform trajectory generation for fiber reinforced polymer composites additive manufacturing with variable-deposition-width","authors":"","doi":"10.1016/j.compositesa.2024.108516","DOIUrl":"10.1016/j.compositesa.2024.108516","url":null,"abstract":"<div><div>Continuous carbon fiber-reinforced polymers (CCFRPs) printing is a unique additive manufacturing (AM) technique that enhances design flexibility and enables on-demand production of lightweight, high-strength composite parts. However, current trajectory generation methods for CCFRPs-AM have limited control over fiber placement and flexible matrix path infill, particularly in complex regions, often using constant deposition widths that restrict path coverage and mechanical properties. To address these limitations, this paper presents a variable-deposition-width (VDW) trajectory generation method for CCFRPs-AM. The approach integrates a streamline-based technique for fiber paths with a Voronoi diagram-based method for matrix path generation, optimizing path placement based on 2D stress fields while accommodating user-defined fiber paths. Mechanical tests by us on fabricated open-hole composite components demonstrate that the proposed approach enhances the interfacial bonding and increases the maximal loading capacity under tensile stress.</div></div>","PeriodicalId":282,"journal":{"name":"Composites Part A: Applied Science and Manufacturing","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Moisture effects on the transverse compressive behaviour of single flax fibres","authors":"","doi":"10.1016/j.compositesa.2024.108509","DOIUrl":"10.1016/j.compositesa.2024.108509","url":null,"abstract":"<div><div>Studying the effects of moisture on the mechanical behaviour of single flax fibres, particularly in the transverse direction, is of key importance for the reliable use of biobased composites exposed to varying humidity levels. In this study, the apparent transverse Young’s modulus evolution of single flax fibres is recorded through repeated compressive load/unload cycles conducted at three Relative Humidity (RH) levels— 40<!--> <!-->%, 60<!--> <!-->%, and 80<!--> <!-->%. No significant changes in the apparent Young’s modulus, determined from the unloading, were observed during transverse compression cycling or under increasing humidity conditions. The absence of apparent softening with the rise in RH is attributed to the expression of two antagonistic mechanisms: wall softening due to plasticization and structural stiffening linked to fibre compaction. Intriguingly, a noteworthy transverse stiffening is recorded at 40<!--> <!-->% RH following the humidification and drying of the fibre. This outcome is ascribed to a hornification phenomenon.</div></div>","PeriodicalId":282,"journal":{"name":"Composites Part A: Applied Science and Manufacturing","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Strong high-density composites from wheat straw","authors":"","doi":"10.1016/j.compositesa.2024.108533","DOIUrl":"10.1016/j.compositesa.2024.108533","url":null,"abstract":"<div><div>Wheat straw represents a promising resource for structural materials due to its inherent strength and availability as an underutilized agricultural by-product. However, structural features such as small diameters and a hollow, low-density design, as well as a hydrophobic, waxy surface layer, hinder conventional processing. We present an approach to overcome these hindrances by engineering delignified and densified straw strands into a mechanically strong unidirectional composite material. Wheat straw split into strands along the fiber direction was subjected to water-based and mild alkaline pre-treatments and subsequently densified. As a result, the average tensile strength and modulus of elasticity of straw strands improved to impressive 466 MPa and 26 GPa, respectively. Simultaneously, chemical changes to the surface enabled better adhesive bonding. The resulting unidirectional straw composites exhibited a flexural strength of 190 MPa and an elastic modulus of 20 GPa, well within the range of established wood and bamboo-based materials.</div></div>","PeriodicalId":282,"journal":{"name":"Composites Part A: Applied Science and Manufacturing","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Process-structure–property study of 3D-printed continuous fiber reinforced composites","authors":"","doi":"10.1016/j.compositesa.2024.108538","DOIUrl":"10.1016/j.compositesa.2024.108538","url":null,"abstract":"<div><div>3D-printed fiber-reinforced composites hold many advantages compared to conventional composites in terms of individualization, mass customization, design freedom, and tailoring the composite geometry to load-bearing specifications. Among candidate continuous fibers for reinforcement, basalt fibers (BFs) serve as an eco-friendly alternative with excellent physical and thermal properties. However, the applicability of continuous BFs to be used for 3D-printed polymer composites was rarely addressed in existing literature. Especially, the effects of impregnation density during manufacturing and the influence of local fiber distribution on the fracture behavior of BF-reinforced composites remain unclear. In this study, a solution coating process was employed as a fiber pre-treatment to improve the packing density of BF in a polylactide (PLA) matrix. The effects of the resulting fiber volume fraction (8–31 %) and the local fiber distribution on the tensile fracture mechanisms of 3D printed BF/PLA samples are thoroughly analyzed using three-dimensional X-ray tomography. It was found that at a concentration of 3 wt%, the coating solution uniformly dispersed optimally between the fibers, resulting in improved impregnation densities of the BF in the PLA matrix. Thus, the resulting composite exhibited a tensile strength of 175 MPa and a Young’s modulus of 6.2 GPa, respectively. A standard linear solid (SLS) model is used for property prediction within a composite design framework to be applied to 3D-printed BF/PLA structures. The model is validated with experimental data from tensile tests. The obtained results demonstrate the applicability of eco-friendly BF/PLA composites for 3D printing of industrial high-performance applications with an individualized property profile.</div></div>","PeriodicalId":282,"journal":{"name":"Composites Part A: Applied Science and Manufacturing","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ultrahigh room and high − temperature mechanical properties of SiCf/SiC composites prepared by hybrid CVI and PIP methods: Effects of PIP temperature","authors":"","doi":"10.1016/j.compositesa.2024.108502","DOIUrl":"10.1016/j.compositesa.2024.108502","url":null,"abstract":"<div><div>Unidirectional (UD) SiC<sub>f</sub>/SiC composites were prepared using chemical vapor infiltration (CVI)-polymer infiltration and pyrolysis (PIP) hybrid procedure at different PIP temperatures of 1100 °C (1100PIP), 1300 °C (1300PIP), and 1500 °C (1500PIP). The effect of PIP temperature on the microstructure of each component was studied. Results showed that SiC fiber strength and interfacial shear strength (IFSS) were the main factors affecting the mechanical properties of the composite. At 1100 °C, the fiber was thermally stable and IFSS was high, due to which 1100PIP achieved ultrahigh mechanical performance with tensile strength of 901.0 ± 87.7 MPa, flexural strength of 2186.5 ± 192.5 MPa, and toughness of 80.6 ± 12.0 MPa·m<sup>1/2</sup>. At 1300 °C, IFSS decreased slightly, due to the crystallization of BN interphase. Hence, the mechanical performance of 1300PIP decreased slightly to 789.8 ± 42.9 MPa, 1935.9 ± 163.2 MPa, and 58.2 ± 4.0 MPa·m<sup>1/2</sup>, respectively. At 1500 °C, severe fiber ceramization and decrease in IFSS caused severe decline in mechanical performance to about half of that of 1100PIP. The crack could be deflected not only at the fiber/BN (F/B) interface, but also at the CVI SiC/PIP SiC (C/P) interface, due to the existence of free carbon layers at the C/P interface, which played an important role in improving the strength and toughness of the composite. 1300PIP also showed excellent strength at high − temperature. At 1350 °C and 1500 °C, its flexural strengths were as high as 1529.0 ± 73.0 MPa and 1223.1 ± 81.1 MPa, respectively. The thermal conductivity and thermal expansion coefficient were also tested. Their values were mainly affected by the grain size and thermal stabilities of the SiC fiber and PIP matrix.</div></div>","PeriodicalId":282,"journal":{"name":"Composites Part A: Applied Science and Manufacturing","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Joule debonding of carbon reinforced polymer (CFRP) lap shear joints bonded with graphene nanoplatelets (GNPs)/epoxy nanocomposites","authors":"","doi":"10.1016/j.compositesa.2024.108535","DOIUrl":"10.1016/j.compositesa.2024.108535","url":null,"abstract":"<div><div>The potential of Joule heating CFRPs joints bonded with conductive graphene/epoxy nanocomposites as adhesives for a selective debonding was investigated. To ensure a localized softening of the bondline without altering the adherend’s structure, the epoxy used in the adhesive’s formulation was chosen to have a considerably lower <em>T<sub>g</sub></em> than the adherend. Joule heating the bondline considerably reduced the lap shear strength (LSS) relative to when the test was performed at room temperature, due to thermally induced structural changes promoted in the polymer network, which was consistent with the nanocomposites’ thermomechanical behavior predicted by DMTA. The minimum LSS value was reached in the vicinity of the adhesive’s <em>T<sub>g</sub></em>, allowing an ease deconstruction of the joints. SEM characterization of their fracture surfaces revealed that by controlling the adhesive’s formulation and their Joule heating the joints’ failure mechanism can be tuned to ensure the recovery of undamaged adherends that can be reused.</div></div>","PeriodicalId":282,"journal":{"name":"Composites Part A: Applied Science and Manufacturing","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The effect of the Weibull modulus on the shape of the stress–strain curves of thin-ply pseudo-ductile hybrid composites","authors":"","doi":"10.1016/j.compositesa.2024.108532","DOIUrl":"10.1016/j.compositesa.2024.108532","url":null,"abstract":"<div><div>This paper presents a numerical approach using ABAQUS CAE scripting to simulate the mechanical response of thin-ply pseudo-ductile hybrid composites. A parametric study demonstrates that interface critical fracture energy is essential for accurately modeling damage mechanisms and mechanical behavior. Correct shear strength identification enables the model to capture experimental observations, including fragmentation and the plateau region in the stress–strain curve. The analysis shows that the mechanical behavior of these composites is largely independent of fragmentation location patterns in the low-strain layer. Results emphasize the significant impact of the Weibull modulus on the stress–strain response, with careful selection leading to strong correlation with experimental data. Notable differences in best-fit Weibull moduli were observed for different materials, with higher values for high modulus carbon fibers.</div></div>","PeriodicalId":282,"journal":{"name":"Composites Part A: Applied Science and Manufacturing","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Low-velocity impact response of hybrid sheet moulding compound composite laminates","authors":"","doi":"10.1016/j.compositesa.2024.108527","DOIUrl":"10.1016/j.compositesa.2024.108527","url":null,"abstract":"<div><div>This work presents a comprehensive study on the impact damage tolerance of Sheet Moulding Compounds (SMCs). The performance of glass, carbon and hybrid glass/carbon SMCs are compared by means of tensile, compression, low-velocity impact and compression after impact experiments. Damage analysis of the impacted laminates was performed by ultrasonic and X-ray methodologies. The glass SMC exhibited the highest damage tolerance in low-velocity impact with the smallest damaged area, crack density and loss in compression after impact (CAI) strength. On the other hand, the carbon SMC demonstrated superior in-plane stiffness and strength, but exhibited a large damaged area and crack density under impact. The hybrid SMC displayed an optimal compromise, exhibiting intermediate tensile in-plane performance and excellent damage tolerance at lower impact energy levels, but suffered from extensive delamination at the highest impact energy. Overall, the findings highlight the suitability of hybrid SMCs for structural applications with potential impact risks.</div></div>","PeriodicalId":282,"journal":{"name":"Composites Part A: Applied Science and Manufacturing","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}