scholarly journals Influence of the cooling behaviour on mechanical properties of carbon fibre-reinforced thermoplastic/metal laminates

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Camilo Zopp ◽  
Daisy Nestler ◽  
Nadine Buschner ◽  
Carola Mende ◽  
Sven Mauersberger ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibre ◽  
Cooling Rate ◽  
Thermoplastic Polyurethane ◽  
Polyamide 6 ◽  
Shear Properties ◽  
Cooling Rates ◽  
Hybrid Laminates ◽  
Fast Cooling ◽  
Interlaminar Shear

For several years, thermoplastic hybrid laminates form a new class in the field of material compounds. These laminates consist of fibre-reinforced plastic prepregs and metal layers in alternating order. Compared to conventional thermosetting multilayer composites, these laminates are suitable for large-scale production and can be manufactured with significantly reduced cycle times in the thermoforming process.  In the framework of this contribution, the influence of the cooling rate of carbon fibre-reinforced thermoplastic composites and hybrid laminates was investigated with regard to crystallinity and the resulting mechanical properties. Polyamide 6 and thermoplastic polyurethane as matrix systems were examined, in particular.Additionally, the differential scanning calorimetry was used in order to investigate the influence of the cooling rate on the crystallisation behaviour. It could be determined that the cooling rate has a limited influence on the crystallisation of polyamide 6 and this influences the mechanical properties. Furthermore, a reliance of process parameters on the characteristics profile of composite materials and material compounds with thermoplastic polyurethane could be identified. Depending on process conditions, tensile, bending, and interlaminar shear properties fluctuate up to 20 % in fibre-reinforced laminates and up to 32 % in hybrid laminates. Moderate to fast cooling rates result in optimum mechanical characteristics of tensile properties in fibre-plastic-compounds. Fast to very fast cooling rates are advisable for bending and interlaminar shear properties. Highest tensile and bending characteristics are achieved in hybrid laminates by using fast to very fast cooling rates, while interlaminar shear properties tend to be highest in slow to moderate cooling rates.

CATPUAL - An Innovative and High-Performance Hybrid Laminate with Carbon Fibre-Reinforced Thermoplastic Polyurethane

2017 ◽  
Vol 742 ◽  
pp. 294-301 ◽  
Author(s):  
Camilo Zopp ◽  
Daisy Nestler ◽  
Jürgen Tröltzsch ◽  
Maik Trautmann ◽  
Sebastian Nendel ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
High Performance ◽  
Bending Strength ◽  
Thermoplastic Polyurethane ◽  
Structural Diversity ◽  
Thermoplastic Matrix ◽  
Hybrid Laminates ◽  
Interlaminar Shear ◽  
The Individual ◽  
Hybrid Laminate

In consideration of environmental aspects and limited availability of resources, the focus of automotive and aerospace industry lies on significant weight optimisations especially for moving loads. In this context, innovative lightweight materials as well as material combinations need to be developed. A considerable potential for lightweight structures can be found in fibre- or textile-reinforced semi-finished products. Due to their specific characteristics and extraordinary structural diversity, thermoset and thermoplastic matrix systems can be used. In particular, carbon fibres as reinforcing components combined with a thermoplastic matrix polymer are able to create new high-performance applications. Besides the significant lightweight characteristics of the fibre-plastic-composites, in some instances contrary requirements must be satisfied in many areas, such as strength and ductility. In this field, the combination of fibre-reinforced polymers with aluminium or titanium sheets creates unique composite materials, so called hybrid laminates, which fulfil the unusual expectations.The focus of the current study lies on the development of a new thermoplastic hybrid laminate named CATPUAL (CArbon fibre-reinforced Thermoplastic PolyUrethane/ALuminium laminate). The structure of the laminate is an alternating sequence of thin aluminium sheets (EN AW 6082-T4) and fibre-reinforced thermoplastic polyurethane (TPU). The individual layers are consolidated to each other by using a hot pressing process. First results showed that the impregnation capability of thermoplastic polyurethane surpasses any other commercially available hybrid laminates. Furthermore, the mechanical properties regarding bending strength and interlaminar shear strength are exceeding the state of the art drastically.

Effect of Ultra-Fast Cooling Rate on the Microstructure and Mechanical Properties of High Strength Cold-Rolled Sheet under Continuous Annealing

2018 ◽  
Vol 913 ◽  
pp. 311-316
Author(s):  
Kai Zhang ◽  
Ren Bo Song ◽  
Feng Gao ◽  
Wen Jie Niu ◽  
Chi Chen
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Cooling Rate ◽  
High Strength ◽  
Rolled Sheet ◽  
Cooling Rates ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size ◽  
Cold Rolled ◽  
Fast Cooling

The effect of different fast cooling rates on the microstructure and mechanical properties of the V and Ti microalloyed high strength cold-rolled sheet was studied under laboratory conditions. Five different fast cooling rates were set up as 20°C/s, 50°C/s, 200°C/s, 500°C/s and 1000°C/s, respectively. Optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to observe the microstructure, and the mechanical properties were also tested. The results showed that with the increase of fast cooling rate from 20°C/s to 1000°C/s, the grains of martensite and ferrite were finer, and the average grain size of both martensite and ferrite decreased from 7.7μm to 3.9μm. The proportion of ferrite in the two phases decreased while that of the martensite increased from 25.7% to 62.1%. The morphology of martensite tended to be lath, and the density of dislocation in the ferrite grains nearby the martensite gradually increased. With cooling rate rising from 20°C/s to 1000°C/s, the yield strength of the experimental steel increased from 381MPa to 1074MPa, and the tensile strength increased from 887MPa to 1199MPa. And the elongation decreased from 14.2% to 7.2%, and the product of strength and elongation decreased from 12.6GPa·% to 8.6GPa·%.

scholarly journals Preparation and Performance of Different Modified Ramie Fabrics Reinforced Anionic Polyamide-6 Composites

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 226 ◽  
Author(s):  
Ze Kan ◽  
Hao Shi ◽  
Erying Zhao ◽  
Hui Wang
Keyword(s):  
Mechanical Properties ◽  
Coupling Agent ◽  
Flexural Modulus ◽  
Interaction Mechanism ◽  
Polyamide 6 ◽  
Dynamic Mechanical Properties ◽  
Interlaminar Shear ◽  
And Performance ◽  
High Level ◽  
Alkali Modification

Anionic polyamide-6 (APA-6) composites are prepared by the VARIM process using different modified ramie fabrics to study the structure and properties of different composites. This study can not only evaluate the optimal modification method for the ramie fabrics, but also further explore the interface interaction mechanism between ramie fabrics and APA-6. In this article, the ramie fabrics are modified by a pretreatment, coupling agent and alkali modification. Different modification methods have different effects on the structure, surface properties and mechanical properties of ramie fabrics, which will further affect the impregnation process, interfacial and mechanical properties of the composites. Through the performance analysis of different modified ramie fabrics reinforced APA-6 composites, the conversion, crystallinity and molecular weight of these composites are at a high level, which indicate that the polymerization of these composites is well controlled. The coupling agent modified ramie fabrics composites and the pretreated ramie fabrics composites have higher flexural modulus, tensile strength and dynamic mechanical properties. Alkali-modified ramie fabrics composites have slightly lower mechanical properties, which however have the highest interlaminar shear strength and outperformed interface properties of the composites.

Specific Mechanical Properties of New Hybrid Laminates with Thermoplastic Matrix and a Variable Metal Component

2015 ◽  
Vol 825-826 ◽  
pp. 344-352 ◽  
Author(s):  
Daisy Nestler ◽  
Heike Jung ◽  
Sebastian Arnold ◽  
Bernhard Wielage ◽  
Guntram Wagner
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Carbon Fibre ◽  
Aluminium Alloy ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Glass Fibre ◽  
Reinforced Plastics ◽  
Hybrid Laminates ◽  
Reinforced Thermoplastics

Hybrid laminates combine the positive properties of metals and fibre reinforced plastics. Thereby, the relatively free selectable components provide further benefits. Especially thermoplastic matrices offer positive aspects like the possibility of deformation, recyclability as well as the possibility of mass production. To obtain such hybrid laminates the first step is the production of pre-consolidated unidirectional endless fibre reinforced thermoplastic foils. In a second step, these pre-impregnated fibre-foil tapes were alternating thermally pressed with metallic layers in tailored compositions. To use the full capacity of the hybrid laminates an adequate interface between the fibre reinforced thermoplastics and the metallic foil is essential. Different investigations of the authors display the principle possibility to produce hybrid laminates with carbon endless fibre reinforced thermoplastics and aluminium alloy foils. Nevertheless, load free delamination’s occurs. The reason for these delaminations within the interface of the fibre reinforced thermoplastics and the metallic foil are the differences in the thermal expansion coefficient of the components. Caused by the consolidation at elevated temperatures these differences become more significant and reduce the reproducibility of the hybrid laminates. To minimize these thermal induced stresses the graduation of the thermal expansion coefficient is one possibility. This graduation is possible by utilising glass fibre thermoplastic tapes between the aluminium alloy foil and the carbon fibre reinforced thermoplastics. Further investigations are dealing with so called expansion alloys to adapt the thermal expansion coefficient. The latter approach provides the benefit to utilize the full mechanical properties of the carbon fibre reinforced thermoplastics and to economize the glass-fibre tapes. Nevertheless, these expansion alloys are characterized by a high density. Hence, within this contribution the specific mechanical properties as well as the advantages and disadvantages of hybrid laminates with expansion alloys or aluminium alloys with glass-fibre thermoplastics interlayers are discussed and assessed. These specific mechanical properties display the potential of the expansion alloy in spite of the high density by means of comparable values. The sample only consisting of carbon fibre reinforced plastics highlights the great variety and possibilities of different hybrid laminate structures and combinations regarding the thickness and positioning of the component layers.

Effect of the Cooling Rate on Crystallinity and Tensile Strength of Two PVDF Grades

2015 ◽  
Author(s):  
Caroline Slikta Velloso ◽  
Geovanio Lima de Oliveira ◽  
Christine Rabello Nascimento ◽  
Celio Albano da Costa Neto
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cooling Rate ◽  
Vinylidene Fluoride ◽  
Processing Technique ◽  
Processing Conditions ◽  
Poly Vinylidene Fluoride ◽  
Fast Cooling

The PVDF (poly(vinylidene fluoride)) is the recommended material for pressure barrier application when the temperature is above 90 C and below 130 C (API Specification 17J). Two grades of PVDFs used in flexible raisers were processed. The grades selected were those for extrusion, but they were compression molded instead. The processing conditions were the same for each grade, from slow to fast cooling rate. The results allowed the evaluation of their performance using a simpler processing technique and, also, to observe how the mechanical properties varied with the cooling rate applied.

scholarly journals Experimental Investigation of In-Plane Shear Behaviour of Thermoplastic Fibre-Reinforced Composites under Thermoforming Process Conditions

2021 ◽  
Vol 5 (9) ◽  
pp. 248
Author(s):  
Nikita Pyatov ◽  
Harish Karthi Natarajan ◽  
Tim A. Osswald
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Sheet Material ◽  
Matrix Material ◽  
Shear Behaviour ◽  
Temperature Cycle ◽  
Process Conditions ◽  
Cooling Rates ◽  
Dsc Measurements ◽  
Thermoforming Process

In order to meet environmental regulations and achieve resource efficiency in the series production of vehicles, recyclable polymer composites with a high strength-to-weight ratio are increasingly being used as materials for structural components. Particularly with thermoplastic fibre-reinforced polymers or organo-sheets, the advantage lies in the tailored mechanical properties of the final component by adapting the orientation of fibres based on the direction of loads. These components produced by thermoforming organo-sheets also offer a cost benefit and short cycle times. During the thermoforming process, the shear behaviour of the organo-sheet is the most dominant and determines the mechanical properties and quality of the resulting component. However, the current standard for characterising the shear behaviour of organo-sheets does not consider the strain and cooling rates inherent in the thermoforming process. This research investigates the influence of thermoforming process parameters on the shear behaviour of organo-sheets with a new methodology combining DSC and DMA experiments. During the thermoforming process, the transition of the matrix material from a molten state to a solid state is dictated by the crystallisation kinetics and their dependence on heating and cooling rates. Thus, non-isothermal DSC scans, which correspond to a temperature cycle in a thermoforming process, are used in the DSC experiments to establish the relationship between the recrystallisation temperature of the organo-sheet material and the cooling/heating rates in the thermoforming process. In order to achieve thermoforming-process-relevant cooling rates, fast scanning calorimetry (Flash DSC) is used in addition to conventional DSC measurements. DMA experiments carried out with 45° fibre orientation show that the recrystallisation temperature consequently influences the shear storage modulus of the organo-sheet. The results from DSC measurements show a shift of recrystallisation temperatures to lower temperatures as the cooling rate increases. The combined analysis of results from the DSC and DMA experiments supports the findings and shows the influence of the process temperature, cooling rate and strain rate on the recrystallisation temperature and, in turn, the shear behaviour of organo-sheets. Thus, a recommendation for establishing a new standard for characterising the shear behaviour of organo-sheets is made.

scholarly journals Improved Mechanical Properties of Copoly(Phthalazinone Ether Sulphone)s Composites Reinforced by Multiscale Carbon Fibre/Graphene Oxide Reinforcements: A Step Closer to Industrial Production

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 237 ◽  
Author(s):  
Nan Li ◽  
Xiuxiu Yang ◽  
Feng Bao ◽  
Yunxing Pan ◽  
Chenghao Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Carbon Fibre ◽  
Photoelectron Spectroscopy ◽  
Fibre Surface ◽  
Homogeneous Distribution ◽  
Matrix Interface ◽  
Atomic Force ◽  
Hybrid Fibre ◽  
Interlaminar Shear

The properties of carbon fibre (CF) reinforced composites rely heavily on the fibre-matrix interface. To enhance the interfacial properties of CF/copoly(phthalazinone ether sulfone)s (PPBES) composites, a series of multiscale hybrid carbon fibre/graphene oxide (CF/GO) reinforcements were fabricated by a multistep deposition strategy. The optimal GO loading in hybrid fibres was investigated. Benefiting from the dilute GO aqueous solution and repeated deposition procedures, CF/GO (0.5%) shows a homogeneous distribution of GO on the hybrid fibre surface, which is confirmed by scanning electron microscopy, atomic force microscope, and X-ray photoelectron spectroscopy, thereby ensuring that its PPBES composite possesses the highest interlaminar shear strength (91.5 MPa) and flexural strength (1886 MPa) with 16.0% and 24.1% enhancements, respectively, compared to its non-reinforced counterpart. Moreover, the incorporation of GO into the interface is beneficial for the hydrothermal ageing resistance and thermo-mechanical properties of the hierarchical composite. This means that a mass production strategy for enhancing mechanical properties of CF/PPBES by regulating the fiber-matrix interface was developed.

Effect of polyamide 6 on the mechanical behavior of thermoplastic polyurethanes/polyamide 6 blends

2021 ◽  
pp. 095440542110406
Author(s):  
Nga Thi-Hong Pham
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mechanical Behavior ◽  
Thermoplastic Polyurethane ◽  
Polyamide 6 ◽  
Thermoplastic Polyurethanes ◽  
Microscope Images ◽  
Scanning Electron

Ductility and tensile strength are among the basic mechanical properties of polymers. Generally, it is difficult to enhance the ductility without significantly reducing the tensile strength. In this study, thermoplastic polyurethane (TPU) is mixed with 0%, 2.5%, 5%, 7.5%, 10%, and 12.5% polyamide 6 (PA6). The results show that the sample containing 100% TPU has the largest elongation of 690.5%. When PA6 is added, the elongation decreases gradually to 635.0%, 623.1%, 529.5%, 476.0%, 391.3%, and 242.8%, corresponding to 2.5%, 5%, 7.5%, 10%, 12.5%, and 100% PA6, respectively. The tensile strengths are 36.7, 33.8, 29.4, 26.5, 23.1, and 24.9 MPa, corresponding to 0%, 2.5%, 5%, 7.5%, 10%, and 12.5% PA6 samples, respectively. The tensile strength decreases gradually when the PA6 content is increased. Notably, the tensile strength of the 12.5% PA6 sample increases compared to the 10% PA6 sample. In addition, the hardness of the TPU/PA blend increases slightly as the PA6 ratio is increased. Finally, scanning electron microscope images demonstrate that PA6 particles act as particles dispersed or dissolved in TPU/PA blends.

Sign in / Sign up

Export Citation Format

Share Document