scholarly journals Influence of Polyurea Composite Coating on Selected Mechanical Properties of AISI 304 Steel

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3137 ◽  
Author(s):  
Monika Duda ◽  
Joanna Pach ◽  
Grzegorz Lesiuk

This paper contains experimental results of mechanical testing of the AISI 304 steel with composite coatings. The main goal was to investigate the impact of the applied polyurea composite coating on selected mechanical properties: Adhesion, impact resistance, static behavior, and, finally, fatigue lifetime of notched specimens. In the paper the following configurations of coatings were tested: EP (epoxy resin), EP_GF (epoxy resin + glass fabric), EP_GF_HF (epoxy resin + glass fabric hemp fiber), EP_PUA (epoxy resin + polyurea) resin, EP_GF_PUA (epoxy resin + glass fabric + polyurea) resin, and EP_GF_HF_PUA (epoxy resin + glass fabric + hemp fiber + polyurea) resin. The highest value of force required to break adhesive bonds was observed for the EP_PUA coating, the smallest for the single EP coating. A tendency of polyurea to increase the adhesion of the coating to the base was noticed. The largest area of delamination during the impact test was observed for the EP_GF_HF coating and the smallest for the EP-coated sample. In all tested samples, observed delamination damage during the pull-off test was located between the coating and the metallic base of the sample.

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4169
Author(s):  
Marcel Zambrzycki ◽  
Krystian Sokolowski ◽  
Maciej Gubernat ◽  
Aneta Fraczek-Szczypta

In this work, we present a comparative study of the impact of secondary carbon nanofillers on the electrical and thermal conductivity, thermal stability, and mechanical properties of hybrid conductive polymer composites (CPC) based on high loadings of synthetic graphite and epoxy resin. Two different carbon nanofillers were chosen for the investigation—low-cost multi-layered graphene nanoplatelets (GN) and carbon black (CB), which were aimed at improving the overall performance of composites. The samples were obtained by a simple, inexpensive, and effective compression molding technique, and were investigated by the means of, i.a., scanning electron microscopy, Raman spectroscopy, electrical conductivity measurements, laser flash analysis, and thermogravimetry. The tests performed revealed that, due to the exceptional electronic transport properties of GN, its relatively low specific surface area, good aspect ratio, and nanometric sizes of particles, a notable improvement in the overall characteristics of the composites (best results for 4 wt % of GN; σ = 266.7 S cm−1; λ = 40.6 W mK−1; fl. strength = 40.1 MPa). In turn, the addition of CB resulted in a limited improvement in mechanical properties, and a deterioration in electrical and thermal properties, mainly due to the too high specific surface area of this nanofiller. The results obtained were compared with US Department of Energy recommendations regarding properties of materials for bipolar plates in fuel cells. As shown, the materials developed significantly exceed the recommended values of the majority of the most important parameters, indicating high potential application of the composites obtained.


2009 ◽  
Vol 79-82 ◽  
pp. 553-556 ◽  
Author(s):  
Ling Fei Shi ◽  
Gang Li ◽  
Gang Sui ◽  
Xiao Ping Yang

The increasing proliferation and application of advanced polymer composites requires higher and broader performance resin matrices. Poly(oxypropylene) with –NH2 end-groups has been widely used to toughen epoxy resins, but the strength of resin matrix may be reduced due to the addition of flexible segments in the crosslinking network. Carbon nanotubes (CNTs) have been paid more and more attention in recent years because of their superior thermal and mechanical properties. In this paper, CNTs grafted with Jeffamines T403 were used to simultaneously improve the reinforcement and toughening of an epoxy resin. The untreated multi-walled carbon nanotubes (u-MWNTs) were functionalized with amine groups according to three steps: carboxylation, acylation, and amidation. The f-MWNTs were characterized by Fourier transform infra-red (FTIR) and X-ray photoelectron spectroscopy (XPS). The experimental results indicated that the T403 was grafted to the surface of MWCNTs. The mechanical and thermal properties of epoxy with f-MWNTs were investigated. The tensile and flexural strength increased by 7.77 % and 7.03 % after adding 0.5wt% f-MWCNTs without sacrificing the impact toughness. At the same time, dynamic mechanical thermal analysis (DMTA) showed that the glass transition temperature (Tg) of epoxy with f-MWNTs were increased. The fracture surface of epoxy with f-MWNTs was observed by scanning electron microscopy (SEM) to understand the dispersion of f-MWNTs in epoxy matrix and interfacial adhesion between f-MWNTs and epoxy matrix, which can be attributed to the strong interfacial bonding between f-MWNTs and epoxy resin.


Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 703
Author(s):  
Xiangping Xu ◽  
Yi Wang ◽  
Chi Liu ◽  
Jiasheng Zou ◽  
Chunzhi Xia

WC-10Ni + AgCuTi composite coating with WC mass fraction of 40% was prepared on the copper surface by vacuum brazing. The brazing temperatures were 830 °C, 860 °C, 890 °C, and 920 °C. The microstructure, interface structure, and hardness of the coating section were studied. The results showed that the composite coatings obtained at different brazing temperatures were better combined. As the brazing temperature increased, the Ni transition layer wrapped around the WC gradually decreased until it disappeared. The brazing seam gradually thickened, the reaction between the coating and the substrate became more and more intense, and more and more Cu was formed on both sides of the brazing seam. Scanning analysis of the interface between the coating and the substrate showed that the elements W and Ti hardly diffused into the brazing seam and the substrate, and the elements Ag and Cu diffused into the substrate. Finally, the interface between the brazing seam and the substrate was metallurgically bonded. The Vickers hardness results and bond strength results of the composite coatings show that the mechanical properties of the coatings are best when the brazing temperature is 890 °C.


2017 ◽  
Vol 309 ◽  
pp. 738-748 ◽  
Author(s):  
M. Naeem ◽  
M. Zaka-ul-Islam ◽  
M. Shafiq ◽  
M.I. Bashir ◽  
J.C. Díaz-Guillén ◽  
...  

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 543
Author(s):  
Yong Chen ◽  
Liangbin Hu ◽  
Changjun Qiu ◽  
Bin He ◽  
Lihua Zhou ◽  
...  

An Al2O3–TiO2 amorphous composite coating with a thickness of 100–120 μm was fabricated on China low activation martensitic steel (CLAM steel) by oxygen acetylene flame spraying technology and the laser in-situ reaction method. We investigated the microstructures and mechanical properties of the coating after liquid lead-bismuth eutectic (LBE) alloy corrosion under different temperatures for 300 h and found that the corrosion temperature of the LBE had no observable effect on the microstructure and chemical phase of the Al2O3–TiO2 amorphous composite coatings. However, the mechanical properties (micro-hardness and shear strength) of the Al2O3–TiO2 multiphase coating deteriorated slightly with the increase in the immersion temperature of the LBE. As a result of oxygen acetylene flame spraying and laser in-situ reaction technology, it was found that the Al2O3–TiO2 amorphous composite coating exhibits an excellent LBE corrosion resistance, which is a candidate structural material for the accelerator-driven subcritical system (ADS) to handle nuclear waste under extreme conditions.


2018 ◽  
Vol 145 ◽  
pp. 05012 ◽  
Author(s):  
Nelly Gidikova ◽  
Maciej Sulowski ◽  
Marcin Madej ◽  
Radoslav Valov ◽  
Vladimir Petkov

Aluminum offers engineers weight saving advantages in their product design. However, aluminum has poor wear and friction properties. In addition, the surface oxide layer of this chemically active metal, which gives it the corrosion resistance, makes it a very difficult metal to plate [1]. Specific pre-treatment must be applied to remove the oxide layer from the aluminum surface. The nanodiamond particles additionally facilitates the process of chromium deposition. The object of this study is to evaluate the impact of nanodiamonds on the mechanical properties of the chromium coating plated on


2008 ◽  
Vol 55-57 ◽  
pp. 553-555
Author(s):  
Haruthai Longkullabutra ◽  
Wim Nhuapeng ◽  
Wandee Thamjaree ◽  
Tawee Tunkasiri

An experimental was investigated the condition of reinforcement of hemp fiber and hemp fiber/epoxy resin composites with carbon nanotubes (CNTs).The CNTs were mixed with several liquid such as ethanol, latex, water glue and epoxy resin. These mixtures were added to hemp fiber and prepared the hemp fiber/epoxy resin composites. The mechanical properties of both fiber and composite samples were measured. It was found that the mixture of epoxy resin and CNTs with CNTs ratio of 20 vol% in hemp fiber showed the highest tensile strength of 25.43 N. and the same mixture in hemp fiber/epoxy resin composites showed the highest tensile strength of 31.82 MPa and elongation of 7.40 %.


Author(s):  
Ishaya Musa Dagwa ◽  
O. Ojo

In Recent Times, Environmental Concerns Arising from Pollution, Global Warming and Waste Management Have Led to the Generation of Interest in the Use of Environmentally Friendly Materials, Especially, Biological Materials such as Natural Fibres and Particulates in Composite Materials Manufacture. in this Work, Natural Fillers (Afara-Mahogany Particulates of 150µm) and Fibre (Caesar Weed Fibre of 5mm Length) Were Mixed with Epoxy Resin at the Various Fibre/filler Weight Percentages as Follows: 2%, 4%, 6%, 8% and 10% with Random Fibre Orientations. some Physical and Mechanical Properties of the Composite Were Determined Using Standard Procedures. Ninety (90) Wt% of Epoxy Resin Mixed with 10 Wt% for each of the Following: Caeser Weed Fibre, Afara and Mahogany, Improved the Tensile Modulus by 2652.6%, 321.37%, and 129.73% and the Impact Strength by 162.7%, 133.9% and 15.25%, Respectively. Also, Composites Density Reduced by 26.26%, 3.03%, and 3.03%, and its Hardness too Reduced by 5.41%, 1.35%, and 4.05%, Respectively. Meanwhile, the Water Absorption Were 4.9%, 2.79%, and 4.12% for 10wt% of Caeser Weed Fibre, Afara and Mahogany, Respectively and 90wt% Epoxy Resin. Therefore, Caeser Weed Fibre Had the Greatest Positive Effect on the Tensile Strength, Impact Energy Absorbed and Density. however, Afara-Epoxy Composite Had the Least Water Absorption and Higher Shore Hardness Value than Mahogany-Epoxy and Caeser Weed Fibre-Epoxy Composites.


2012 ◽  
Vol 535-537 ◽  
pp. 2499-2502
Author(s):  
X. Wang ◽  
S. R. Zheng ◽  
R. M. Wang

Epoxy resin structural adhesives modified by flexible curing agent. Dependening on the mechanical properties of epoxy resins on the flexible curing agent content was studied. The impact fracture toughness was discussed in terms of fracture surface fractography.


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