Identification and enhancement of the thermal and mechanical properties of two types of plasters successively derived from gypsum: from the Safi basin and the High Atlas of Marrakech, Morocco

X Ray Diffraction ◽

High Atlas

Over the past few decades, the construction industry has focused on sustainable, environmentally friendly and easily recyclable materials. The objective of this work is to characterize and enhance the thermal conductivity, mechanical strength and setting time of a composite material based on plaster and lime. This material is designed for use in plasters.Two types of gypsum are studied, the first one belongs to the Safi basin, the second one characterizes the High Atlas of Marrakech and precisely Douar Tafza. Geologically speaking, the two sites have many similarities. They are characterized by a Meso-Cenozoic age coverage covering a deformed Paleozoic age basement.The characterization of the plaster's raw material, gypsum, was necessary to determine its physical and geotechnical properties, mineralogy, thermal behaviour and microscopic structure. Several analyses have been developed such as: pycnometer density measurement, X-ray diffraction, infrared spectroscopy and scanning electron microscopy.We made samples, of standardized dimensions, of two mixtures based on the two types of plaster reinforced by the addition of two types of lime from different localities. The latter are from Marrakech and the Agadir region. The water/plaster mass ratio was set at 0.75 and the addition of lime was achieved by increasing its percentage in slices by 12.5% and up to 50%.The reinforcement of plaster with lime has enhanced its thermal and mechanical properties and setting time. The measurements show that the addition of lime has reduced the thermal conductivity and increased the mechanical strength of both types of plaster. In addition, following the addition of lime, the setting time has decreased and the basicity of the material has increased. Noting that the intrinsic properties of the raw material influence the mechanical and thermal properties of the material.Keywords: &#160;&#160;plaster, enhancement, properties, mechanical, thermal, Morocco

Thermal and mechanical characterization of a new material based on two gypsums from different localities : High Atlas of Marrakech and Safi Basin, Morocco

10.5194/egusphere-egu21-11102 ◽

2021 ◽

Author(s):

imane baba ◽

Mounsif Ibnoussina ◽

Omar Witam ◽

Latifa Saadi

Keyword(s):

Setting Time ◽

Density Measurement ◽

Mechanical Resistance ◽

Low Carbon ◽

X Ray Diffraction ◽

High Atlas ◽

New Material ◽

Indoor Comfort

Over the last few decades, the construction industry has become interested in materials that are durable, environmentally friendly and easily recyclable. This interest is due to the advantages these materials offer, among others local availability, low carbon footprint, energy efficiency and indoor comfort. The objective of this work is to study the properties of plasters prepared from a mixture of two types of gypsum. We were interested in the evolution of thermal conductivity, mechanical resistance and setting time as a function of the percentage of addition.Two types of gypsum were studied, the first one belongs to the Safi basin and the second one comes from the High Atlas of Marrakech.The characterization of the gypsums was necessary to determine its physical and geotechnical properties, its mineralogy, its thermal behavior and its microscopic structure. Several analyses were developed such as density measurement by pycnometer, X-ray diffraction, infrared spectroscopy and scanning electron microscopy.We have made samples, of standardized dimensions, of mixtures based on both types of plaster. The water/gypsum mass ratio was set at 0.75.The results revealed that the properties of gypsum as well as the percentage of addition affect the mechanical and thermal properties and the setting time of the composite material. The addition of the High Atlas gypsum of Marrakech allowed improving the material in terms of thermal insulation. The results of the other tests will be communicated later.

Mechanical and thermal properties of tungsten carbide – graphite nanoparticles nanocomposites

Polish Journal of Chemical Technology ◽

10.1515/pjct-2016-0033 ◽

2016 ◽

Vol 18 (2) ◽

pp. 84-88 ◽

Cited By ~ 2

Author(s):

Kamil Kornaus ◽

Agnieszka Gubernat ◽

Dariusz Zientara ◽

Paweł Rutkowski ◽

Ludosław Stobierski

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Thermal Properties ◽

Tungsten Carbide ◽

Bending Strength ◽

Polycrystalline Materials ◽

Pure Tungsten ◽

Graphite Nanoparticles

Abstract Previous studies concerning pure tungsten carbide polycrystalline materials revealed that nanolayers of graphite located between WC grains improve its thermal properties. What is more, pressure-induced orientation of graphene nano platelets (GNP) in hot pressed silicon nitride-graphene composites results in anisotropy of thermal conductivity. Aim of this study was to investigate if addition of GNP to WC will improve its thermal properties. For this purpose, tungsten carbide with 0.5–6 wt.% of GNP(12)-additive underwent hot pressing. The microstructure observations performed by SEM microscopy. The anisotropy was determined via ultrasonic measurements. The following mechanical properties were evaluated: Vickers hardness, bending strength, fracture toughness KIc. The influence of GNP(12) addition on oxidation resistance and thermal conductivity was examined. It was possible to manufacture hot-pressed WC-graphene composites with oriented GNP(12) particles, however, the addition of graphene decreased both thermal and mechanical properties of the material.

Magnesite Effect to the Alumina Sintering for Heat Sink Application

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.465-466.70 ◽

2013 ◽

Vol 465-466 ◽

pp. 70-75

Author(s):

Nor Hafiez Mohamad Nor ◽

Muhammad Hussain Ismail ◽

Nur Atikah Abu Kasim ◽

Wan Dung Teng ◽

M.I.I. Idris

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Heat Sink ◽

Density Measurement ◽

Xrd Analysis ◽

Modern World ◽

X Ray Diffraction ◽

Electronic Components ◽

X Ray ◽

Sintered Temperature

In the modern world with an extensive improvement of science and technologies, alumina (Al2O3) ceramics have been identified as one of the usable materials in production of electronic components. This project attempts to investigate the magnesite (MgCO3) effect to Al2O3 sintering for heat sink application. The effect of MgO percentage varying from 0% to 50% has been in investigated, emphasizing on the flexural strength test, thermal conductivity test, elastic modulus test, shrinkage percentage and density measurement. The result revealed that the MgO give an effect to the final thermal conductivity and mechanical properties of Al2O3 material at high sintering temperature (i.e. at temperature of 1600°C). Throughout an X-ray diffraction (XRD) analysis of Al2O3 and MgO compositions, it was revealed that spinel, periclase and corundum phases exist for all sintered temperature which contributes to strengthen grain boundaries and improved mechanical properties.

Effect of CNT/CNF on Thermal and Mechanical Properties of Cement Mortars

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1049-1050.234 ◽

2014 ◽

Vol 1049-1050 ◽

pp. 234-237 ◽

Cited By ~ 1

Author(s):

Yu Han Zhao

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Compressive Strength ◽

Carbon Nanotube ◽

Mechanical Strength ◽

Phase Change Materials ◽

Carbon Nanofiber ◽

Cement Mortars ◽

Mechanical Performances

The research integrates both phase change materials (PCM) and carbon nanotube (CNT)/carbon nanofiber (CNF) into cement mortars to improve their thermal and mechanical performances. The PCM will improve the thermal storage capability of the cement mortars, while CNT/CNF can improve their mechanical strength and thermal conductivity. Experimental results show that addition of 1 wt. % CNT and CNF into the cement mortars with 5 wt.% PCM can increase their compressive strength by 23% and 8% respectively, and increase their thermal conductivity by 26% and 9% respectively.

Effects of ionic liquid types on the tribological, mechanical, and thermal properties of ionic liquid modified graphene/polyimide shape memory composites

High Performance Polymers ◽

10.1177/0954008321996769 ◽

2021 ◽

pp. 095400832199676

Author(s):

Yuting Ouyang ◽

Qiu Zhang ◽

Xiukun Liu ◽

Ruan Hong ◽

Xu Xu ◽

...

Keyword(s):

Mechanical Properties ◽

Ionic Liquid ◽

Composite Materials ◽

Shape Memory ◽

Recovery Rate ◽

Shape Recovery ◽

Graphene Nanosheets ◽

Modified Graphene

Different ionic liquid modified graphene nanosheets (IG) were induced into polyimide (PI) to improve the tribological, thermal, and mechanical properties of shape memory IG/PI composites. The results demonstrated that when using 1-aminoethyl-3-methylimidazole bromide to modify graphene nanosheets (IG-1), the laser-driven shape recovery rate of IG-1/PI composites (IGPI-1) reached 73.02%, which was 49.36% higher than that of pure PI. In addition, the IGPI-1 composite materials reached the maximum shape recovery rate within 15 s. Additionally, under dry sliding, the addition of IG can significantly improve the tribological properties of composite materials. IGPI-1 exhibited the best self-lubricating properties. Compared with pure PI, the friction coefficient (0.19) and wear rate (2.62 × 10–5) mm3/Nm) were reduced by 44.1% and 24.2%, respectively, and the T10% of IGPI-1 increased by 32.2°C. The Tg of IGPI-1 reached 256.5°C, which was 8.4°C higher than that of pure PI. In addition, the tensile strength and modulus of IGPI-1 reached 82.3 MPa and 1.18 GPa, which were significantly increased by 33.6% and 29.8%, respectively, compared with pure PI. We hope that this work will be helpful for the preparation of shape memory materials with excellent tribological, thermal, and mechanical properties.

Effect of Heat Setting Methods on Structures and Properties of High Strength Polyvinyl Alcohol Fibre

Materials Science Forum ◽

10.4028/www.scientific.net/msf.815.643 ◽

2015 ◽

Vol 815 ◽

pp. 643-648

Author(s):

Yin Zhu ◽

Jiong Xin Zhao

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Polyvinyl Alcohol ◽

Setting Time ◽

High Strength ◽

Single Fibre ◽

X Ray Diffraction ◽

Heat Setting ◽

Heat Treated ◽

Setting Process

The effect of heat setting methods on the structures and mechanical properties of high strength polyvinyl alcohol (PVA) fibre is studied in this article. The microstructure and mechanical properties of heat treated PVA fibre is investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and single fibre electronic tensile strength tester. Results show that the heat setting method with constant tension is a good heat setting method which can largely enhance the tensile strength of PVA fibre. During the heat setting process, the mechanical properties of PVA fibre are greatly affected by the temperature, tension and setting time. When the temperature is 220°C, tension is 5cN/dtex and setting time is 90sec, the tensile strength of PVA fibre increases from 12.0cN/dtex to 16.4cN/dtex in compare with the PVA fibre without heat setting

Flame-retardant MXene/Polyimide Film with Outstanding Thermal and Mechanical Properties Based on the Secondary Orientation Strategy

Nanoscale Advances ◽

10.1039/d1na00415h ◽

2021 ◽

Author(s):

Yue Zhu ◽

Qingyu Peng ◽

Haowen Zheng ◽

Fuhua Xue ◽

Pengyang Li ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Transition Metal ◽

Mechanical Performance ◽

Polyimide Film ◽

Polymeric Films ◽

Two Dimensional ◽

Metal Carbides ◽

Transition Metal Carbides

With the development of multifunction and miniaturization in modern electronics, polymeric films with strong mechanical performance and high thermal conductivity are urgently needed. Two-dimensional transition metal carbides and nitrides (MXenes)...

Influence of additive composition on thermal and mechanical properties of β–Si3N4 ceramics

Journal of Materials Research ◽

10.1557/jmr.2004.0416 ◽

2004 ◽

Vol 19 (11) ◽

pp. 3270-3278 ◽

Cited By ~ 31

Author(s):

Xinwen Zhu ◽

Hiroyuki Hayashi ◽

You Zhou ◽

Kiyoshi Hirao

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Fracture Toughness ◽

Nitrogen Pressure ◽

High Fracture Toughness ◽

Oxygen Impurity ◽

High Fracture ◽

Doped Materials ◽

Gas Pressure Sintering

Dense β–Si3N4 ceramics were fabricated from α–Si3N4 raw powder by gas-pressure sintering at 1900 °C for 12 h under a nitrogen pressure of 1 MPa, using four different kinds of additive compositions: Yb2O3–MgO, Yb2O3–MgSiN2, Y2O3–MgO, and Y2O3–MgSiN2. The effects of additive composition on the microstructure and thermal and mechanical properties of β–Si3N4 ceramics were investigated. It was found that the replacement of Yb2O3 by Y2O3 has no significant effect on the thermal conductivity and fracture toughness, but the replacement of MgO by MgSiN2 leads to an increase in thermal conductivity from 97 to 113 Wm-1K-1and fracture toughness from 8 to 10 MPa m1/2, respectively. The enhanced thermal conductivity of the MgSiN2-doped materials is attributed to the purification of β–Si3N4 grain and increase of Si3N4–Si3N4 contiguity, resulting from the enhanced growth of large elongated grains. The improved fracture toughness of the MgSiN2-doped materials is attributed to the increase of grain size and fraction of large elongated grains. However, the same thermal conductivity between the Yb2O3- and Y2O3-doped materials is related to not only their similar microstructures, but also the similar abilities of removing oxygen impurity in Si3N4 lattice between Yb2O3 and Y2O3. The same fracture toughness between the Yb2O3- and Y2O3-doped materials is consistent with their similar microstructures. This work implies that MgSiN2 is an effective sintering aid for developing not only high thermal conductivity (>110 Wm−1K−1) but also high fracture toughness (>10 MPa m1/2) of Si3N4 ceramics.

Influence of the Direction of Mixture Compaction on the Selected Properties of a Hemp-Lime Composite

Materials ◽

10.3390/ma14164629 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4629

Author(s):

Przemysław Brzyski ◽

Piotr Gleń ◽

Mateusz Gładecki ◽

Monika Rumińska ◽

Zbigniew Suchorab ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Temperature Distribution ◽

Preparation Method ◽

Compaction Process ◽

External Wall ◽

Capillary Uptake ◽

Parallel Direction ◽

The Individual

The aim of the research presented in the article was to check the differences in the hygro-thermal and mechanical properties of hemp-lime composites with different shives fractions, depending on the direction of mixture compaction. The research part of the paper presents the preparation method and investigation on the composites. Thermal conductivity, capillary uptake, as well as flexural and compressive strengths were examined. Additionally, an analysis of the temperature distribution in the external wall insulated with the tested composites was performed. The results confirm that the direction of compaction influences the individual properties of the composites in a similar way, depending on the size of the shives. The differences are more pronounced in the case of the composite containing longer fractions of shives. Both thermal conductivity of the material and the capillary uptake ability are lower in the parallel direction of the compaction process. Composites exhibit greater stiffness, but they fail faster with increasing loads when loaded in the direction perpendicular to compaction.

Mechanical and thermal properties of PP/compatibilized PP/acid treated SWNTs nanocomposites: Effect of different acid treatment times

e-Polymers ◽

10.1515/epoly.2008.8.1.1766 ◽

2008 ◽

Vol 8 (1) ◽

Author(s):

Morteza Ghorbanzadeh Ahangari ◽

Abdolhosein Fereidoon ◽

Seyfolah Saedodin

Keyword(s):

Mechanical Properties ◽

Thermal Properties ◽

Acid Treatment ◽

Treatment Process ◽

Tensile Tests ◽

Acid Mixture ◽

Maleated Polypropylene ◽

Carboxylic Groups

AbstractIn the present work, the effect of different acid treatment times of singlewalled carbon nanotubes (SWNTs) on the mechanical and thermal properties of polypropylene (PP)/maleated polypropylene (PP-g-MA) nanocomposites was investigated. The acid treatment process was based on a mixture of concentrated sulphuric and nitric acids. The SWNTs were treated with the acid mixture for 1, 3, and 6 h. FTIR, Raman spectroscopy and TEM revealed the values of carboxylic groups, graphitization and morphology of acid treated SWNTs, respectively. The thermal and mechanical properties and the morphology of nanocomposites were investigated by tensile tests, DMTA, DSC, and SEM.