Cure kinetics and autoclave-pressure dependence on physical and mechanical properties of woven carbon/epoxy 8552S/AS4 composite laminates

2021 ◽  
pp. 096739112110284
Author(s):  
Abd Baghad ◽  
Khalil El Mabrouk ◽  
Sébastien Vaudreuil ◽  
Khalid Nouneh

The final mechanical properties of composite laminates are highly dependent on their curing cycles in the autoclave. During this cycle, the temperature, pressure, vacuum, and treatment time will influence the quality of manufactured parts. The void content is considered the most harmful defects in carbon/epoxy laminates since they weaken the matrix-dominated mechanical properties such as interlaminar shear and compressive strengths. In the present work, differential scanning calorimetry is used to characterize the influence of time/temperature on the behavior of the epoxy resin. Then, a series of [0/90/−45/+45]s laminates composites are autoclave-cured under various applied pressures to evaluate their impact on microstructure and mechanical properties. The interlaminar shear modulus, interlaminar shear strength, laminate compressive modulus, and laminate compressive strength at room and operating engine temperature were measured. The correlation between microstructure and mechanical properties was also studied. The mechanical properties of manufactured carbon/epoxy laminates are found to be dependent on pressure and microstructure. These results are explored to establish an optimal autoclave pressure route that would minimize porosity without counterbalancing mechanical properties.

2016 ◽  
Vol 35 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Zhiyuan Liang ◽  
Wanhua Sha ◽  
Qinxin Zhao ◽  
Chongbin Wang ◽  
Jianyong Wang ◽  
...  

AbstractThe effect of aging heat treatment on the microstructure and mechanical properties of 10Cr20Ni25Mo1.5NbN austenitic steel was investigated in this article. The microstructure was characterized by scanning electron microscopy, energy dispersive spectrometry and transmission electron microscopy. Results show that the microstructure of 10Cr20Ni25Mo1.5NbN austenitic is composed of austenite. This steel was strengthened by precipitates of secondary phases that were mainly M23C6 carbides and NbCrN nitrides. As aging treatment time increased, the tensile strength first rose (0–3,000 h) and then fell (3,000–5,000 h) due to the decrease of high density of dislocations. The impact absorbed energy decreased sharply, causing the sulfides to precipitate at the grain boundary. Therefore, the content of sulfur should be strictly controlled in the steelmaking process.


2019 ◽  
Vol 38 (2019) ◽  
pp. 404-410 ◽  
Author(s):  
Weijuan Li ◽  
Haijian Xu ◽  
Xiaochun Sha ◽  
Jingsong Meng ◽  
Zhaodong Wang

AbstractIn this study, oxide dispersion strengthened (ODS) ferritic steels with nominal composition of Fe–14Cr–2W–0.35Y2O3 (14Cr non Zr-ODS) and Fe–14Cr–2W–0.3Zr–0.35Y2O3 (14Cr–Zr-ODS) were fabricated by mechanical alloying (MA) and hot isostatic pressing (HIP) technique to explore the impact of Zr addition on the microstructure and mechanical properties of 14Cr-ODS steels. Microstructure characterization revealed that Zr addition led to the formation of finer oxides, which was identified as Y4Zr3O12, with denser dispersion in the matrix. The ultimate tensile strength (UTS) of the non Zr-ODS steel is about 1201 MPa, but UTS of the Zr-ODS steel increases to1372 MPa, indicating the enhancement of mechanical properties by Zr addition.


2010 ◽  
Vol 667-669 ◽  
pp. 457-461
Author(s):  
Wei Guo ◽  
Qu Dong Wang ◽  
Man Ping Liu ◽  
Tao Peng ◽  
Xin Tao Liu ◽  
...  

Cyclic channel die compression (CCDC) of AZ31-1.7 wt.% Si alloy was performed up to 5 passes at 623 K in order to investigate the microstructure and mechanical properties of compressed alloys. The results show that multi-pass CCDC is very effective to refine the matrix grain and Mg2Si phases. After the alloy is processed for 5 passes, the mean grain size decreases from 300 μm of as-cast to 8 μm. Both dendritic and Chinese script type Mg2Si phases break into small polygonal pieces and distribute uniformly in the matrix. The tensile strength increases prominently from 118 MPa to 216 MPa, whereas the hardness of alloy deformed 5 passes only increase by 8.4% compared with as-cast state.


2013 ◽  
Vol 212 ◽  
pp. 59-62 ◽  
Author(s):  
Jerzy Myalski ◽  
Jakub Wieczorek ◽  
Adam Płachta

The change of matrix and usage of the aluminum alloys designed for the metal forming in making the composite suspension allows to extend the processing possibility of this type of materials. The possibility of the metal forming of the composites obtained by mechanical mixing will extend the range of composite materials usage. Applying of the metal forming e.g. matrix forging, embossing, pressing or rolling, will allow to remove the incoherence of the structure created while casting and removing casting failures. In order to avoid the appearance of the casting failures the homogenization conditions need to be changed. Inserting the particles into the matrix influences on the shortening of the composite solidification. The type of the applied particles influenced the sedimentation process and reinforcement agglomeration in the structure of the composite. Opposite to the composites reinforced with one-phase particles applying the fasess mixture (glassy carbon and silicon carbide) triggered significant limitation in the segregation process while casting solidification. Inserting the particles into the AW-AlCu2SiMn matrix lowers the mechanical properties tension and impact value strength. The most beneficial mechanical properties were gained in case of heterofasess composites reinforced with the particle mixture of SiC and glass carbon. The chemical composition of the matrix material (AW-AlCu2SiMn) allows to increase additionally mechanical characteristics by the precipitation hardening reached through heat casting forming.


1982 ◽  
Vol 55 (4) ◽  
pp. 1078-1094 ◽  
Author(s):  
J. L. Turner ◽  
J. L. Ford

Abstract Cord-rubber composite systems allow a visualization of interply shear strain effects because of the compliant nature of the matrix material. A technique termed the pin test was developed to aid this visualization of interply shear strain. The pin test performed on both flat pads and radial tires shows that interlaminar shear strain behavior in both types of specimens is similar, most of the shear strain being confined to a region approximately 10 interly rubber thicknesses from the edge. The observed shear strain is approximately an order of magnitude greater than the applied extensional strain. A simplified mathematical model, called the Kelsey strip, for describing such behavior for a two-ply (±θ) cord-rubber strip has been formulated and demonstrated to be qualitatively correct. Furthermore, this model is capable of predicting trends in both compliant and rigid matrix composites and allows for simplified idealizations. A finite-element code for dealing with such interply effects in a simple but efficient manner predicts qualitatively correct results.


2021 ◽  
pp. 36-45
Author(s):  
E.I. Krasnov ◽  
◽  
V.M. Serpova ◽  
L.G. Khodykin ◽  
A.V. Gololobov ◽  
...  

Presents a literature review in the field of methods for strengthening titanium and its alloys by introducing various refractory particles into the matrix. The main problematic issues related to the chemical nature of refractory particles and titanium alloys that arise during hardening are briefly described. The main structural, physical and mechanical properties and morphology of such metal composite materials are described. The dependence of the influence of various refractory particles and their amount, as well as the effect of heat treatment on the physical and mechanical properties of microns based on titanium alloys, is presented.


Author(s):  
Atoyebi Olumoyewa Dotun ◽  
Adeolu Adesoji Adediran ◽  
Adisa Cephas Oluwatimilehin

The current work reports on the fabrication of composite matrix from saw dust (SD) and recycled polyethylene terephthalate (PET) at different weight ratio by flat-pressed method. Wood plastic composites (WPCs) were made with a thickness of 15 mm after mixing the saw dust and PET followed by a three phase press cycle. Physical properties (Density, Water Absorption (WA) and Thickness Swelling (TS)) and Mechanical properties (Modulus of Elasticity (MOE) and Modulus of Rupture (MOR)) were determined base on the mixing ratios according to the standard. WA and TS were measured after 2 h and 24 h of immersion in water. The results showed that as the density increased, the SD content decreased from 90 % to 50 % into the matrix. However, WA and TS decreases when the PET content increased in the matrix. Remarkably, the MOE and MOR attained a maximum point at 964.199 N/mm2and 9.03 N/mm2respectively in 50 % SD content. In comparism with standard, boards D and E can be classified as medium density boards while A, B and C are low density boards. The results indicated that the fabrication of WPCs from sawdust and PET would technically be feasible for indoor uses in building due to favorable physical properties exhibited. The mechanical properties response showed that it cannot be used for structural or load bearing application.


2020 ◽  
pp. 152808372096074
Author(s):  
Mohamed A Attia ◽  
Marwa A Abd El-baky ◽  
Mostafa M Abdelhaleem ◽  
Mohamed A Hassan

An experimental investigation on the mechanical performance of interlayer hybrid flax-basalt-glass woven fabrics reinforced epoxy composite laminates has been performed. The tensile, flexural, in-plane shear, interlaminar shear, bearing, and impact properties of the fabricated laminates were investigated. Test specimens were fabricated using vacuum bagging process. Failure modes of all specimens were recorded and discussed. Results proved that the mechanical properties of flax-basalt-glass hybrid laminates are highly dominated by the reinforcement combinations and plies stacking sequence. Hybridizing flax fiber reinforced composite with basalt and/or glass fabrics provides an effective method for enhancing its tensile, flexural, in-plane shear, interlaminar shear, and bearing properties as well as controls the impact strength of the composite. The fabricated hybrids are found to have good specific mechanical properties benefits. Amongst the studied flax/basalt/glass hybrids, FBGs has the highest tensile properties, GBFs has the highest flexural and impact properties, and GFBs has the best shear and bearing properties. Flax-basalt-glass hybrid composites with different layering sequence seem to be an appropriate choice for lightweight load bearing structures.


2018 ◽  
Vol 9 (1) ◽  
pp. 53 ◽  
Author(s):  
Jianlong Liu ◽  
Qingjie Wu ◽  
Hong Yan ◽  
Songgen Zhong ◽  
Zhixiang Huang

The effects of rare earth yttrium (Y) additions and the heat treatment process on the microstructure and mechanical properties of as-cast ADC12 aluminum alloy have been investigated. The results showed that the primary Si crystals were significantly refined from long axis to fibrous or granular when the Y content was 0.2 wt%. Compared to the matrix, the mean area and aspect ratio were decreased by 92% and 75%, respectively. Moreover, the Si and Fe-rich phases were spheroidized and refined with a small average size during the solid solution. It was also noted that the copper-rich phases were dissolved into the matrix. Correspondingly, it was found that after metamorphic and heat treatment the ultimate tensile strength (UTS), elongation, and, hardness increased by 81.9%, 69.7%, and 74.8%, respectively, compared to the matrix. The improved mechanical properties can primarily be attributed to the optimization of the microstructure and the refinement of various phases.


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