Alumina fibre FP

A new experimental inorganic fibre currently under development at the Du Pont Company is a continuous filament, polycrystalline a-alumina yarn designated Fibre FP. This fibre is suitable for reinforcing a variety of materials, especially non-ferrous metal castings because of a combination of properties such as high strength and modulus, stability at elevated temperatures, composite castability and potentially low cost. Fibre FP, essentially > 99 % a-Al 2 O 3 , is made by a novel continuous ceramic fibre process utilizing low cost textile fibre spinning technology and is produced as a yarn containing 210 filaments. The modulus of Fibre FP is 379 GPa (55 x 10 6 lbf in -2 ) with a tensile strength of 1380 MPa (200000 lbf in -2 ). The room temperature strength and modulus of the fibre are retained to about 1000 °C. Recently, higher strength FP fibres with a tensile strength of 2070 MPa (300000 lbf in -2 ) have been demonstrated on a laboratory scale.

2020 ◽  
Vol 15 (4) ◽  
Author(s):  
Mahesh Mallampati ◽  
Sreekanth Mandalapu ◽  
Govidarajulu C

The composite materials are replacing the traditional materials because oftheir superior properties such as high tensile strength, low thermal expansion, high strength to weight ratio, low cost, lightweight, high specific modulus, renewability and biodegradability which are the most basic & common attractive features of composites that make them useful for industrial applications. The developments of new materials are on the anvil and are growing day by day. The efforts to produce economically attractive composite components have resulted in several innovative manufacturing techniques currently being used in the composites industry. Generally, composites consist of mainly two phases i.e., matrix and fiber. In this study, woven roving mats (E-glass fiber orientation (-45°/45°,0°/90°, - 45°/45°),UD450GSM)were cut in measured dimensions and a mixture of Epoxy Resin (EPOFINE-556, Density-1.15gm/cm3), Hardener (FINE HARDTM 951, Density- 0.94 gm/cm3) and Acetone [(CH3)2CO, M= 38.08 g/mol] was used to manufacture the glass fiber reinforced epoxy composite by hand lay-up method. Mechanical properties such as tensile strength, SEM analysis, hardness test, density tests are evaluated.


2021 ◽  
Author(s):  
Budi Arifvianto ◽  
Teguh Nur Iman ◽  
Benidiktus Tulung Prayoga ◽  
Rini Dharmastiti ◽  
Urip Agus Salim ◽  
...  

Abstract Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material. In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been printed with various extruder temperatures, i.e., 190–230 °C, and raster angles, i.e., 0–90°. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr’s circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 °C and raster angle of 0° could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.


1995 ◽  
Vol 10 (6) ◽  
pp. 1485-1490 ◽  
Author(s):  
X.F. Yang

A self-constraint strengthening mechanism for multilayered brittle materials is proposed. The strengthening is a result of the self-constraint of the individual layers on each other, and no additional reinforcements are needed. The proposed model predicts that when individual brittle layers are stacked and properly “glued” together with a weak interphase, each layer will be ensured a minimum tensile strength, regardless of the flaw size in the individual layers. Estimation of the minimum strength using this model yields an apparently close agreement with the measured values for one type of nacreous structure reported in the literature. It is also predicted that low-strength ceramic sheets, which might be produced by some low-cost fabrication techniques, can be used to construct high strength man-made nacreous ceramics.


2016 ◽  
Vol 48 (5) ◽  
pp. 687-695 ◽  
Author(s):  
D. Arsić ◽  
M. Djordjević ◽  
J. Zivković ◽  
A. Sedmak ◽  
S. Aleksandrović ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5313 ◽  
Author(s):  
Nao Lv ◽  
Hai-bo Wang ◽  
Qi Zong ◽  
Meng-xiang Wang ◽  
Bing Cheng

In view of the devastating outcomes of fires and explosions, it is imperative to research the dynamic responses of concrete structures at high temperatures. For this purpose, the effects of the strain rate and high temperatures on the dynamic tension behavior and energy characteristics of high-strength concrete were investigated in this paper. Dynamic tests were conducted on high-strength concrete after exposure to the temperatures of 200, 400, and 600 °C by utilizing a 74 mm diameter split Hopkinson pressure bar (SHPB) apparatus. We found that the quasi-static and dynamic tensile strength of high-strength concrete gradually decreased and that the damage degree rose sharply with the rise of temperature. The dynamic tensile strength and specific energy absorption of high-strength concrete had a significant strain rate effect. The crack propagation law gradually changed from directly passing through the coarse aggregate to extending along the bonding surface between the coarse aggregate and the mortar matrix with the elevation of temperature. When designing the material ratio, materials with high-temperature resistance and high tensile strength should be added to strengthen the bond between the mortar and the aggregate and to change the failure mode of the structure to resist the softening effect of temperature.


2005 ◽  
Vol 488-489 ◽  
pp. 265-268 ◽  
Author(s):  
Y.Q. Ma ◽  
Rong Shi Chen ◽  
En Hou Han

A new steel mold gravity casting magnesium alloy of low-cost, high strength, and high ductility has been developed and studied. This new magnesium alloy, which is designated as IMR-41, exhibits high strength (Yield Tensile Strength≈145 MPa, Ultimate Tensile Strength≈280 MPa) and high ductility (Elongation≈8%) at room temperature. The alloying elements are inexpensive ones and the cost of IMR-41 is similar to AZ91 series. The influence of small X element addition and heat treatment on the microstructures and mechanical properties are discussed. The IMR-41 combines the virtues of AZ91 series and AM60 series to some extend and shows great potential application on wheels of lightweight vehicles or motorcycles, etc. which require high strength and high ductility simultaneously.


Experimental test have carried out to investigate the behavior of residual tensile strength of concrete prepared using normal and high strength concrete. For the same purpose, cylindrical and prism-shaped specimens of concrete were caste and consecutively subjected to heating and cooling condition in the laboratory-controlled environment. A hold period of three hours was provided to impart the heating-cooling phenomenon inside the electrical furnace at four different sets of temperatures. The elevated temperatures chosen for the present tensile behavior study are 200oC, 400oC, 600oC, and 800oC. Strength was also determined at the ambient environment for the purpose of comparing the effects of thermal loads on the behavior of strength. A significant loss in tensile strength has been observed in concrete mixes at various temperatures. The outcomes of the current experimental work are termed useful for understanding key mechanical characteristics of concrete under the effect of thermal loads.


Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 35
Author(s):  
Filippo Belelli ◽  
Riccardo Casati ◽  
Martina Riccio ◽  
Alessandro Rizzi ◽  
Mevlüt Y. Kayacan ◽  
...  

The number of available materials for Laser Powder Bed Fusion is still limited due to the poor processability of many standard alloys. In particular, the lack of high-strength aluminium alloys, widely used in aerospace and automotive industries, remains a big issue for the spread of beam-based additive manufacturing technologies. In this study, a novel high-strength aluminium alloy for high temperature applications having good processability was developed. The design of the alloy was done based on the chemical composition of the widely used EN AW 2618. This Al-Cu-Mg-Ni-Fe alloy was modified with Ti and B in order to promote the formation of TiB2 nuclei in the liquid phase able to stimulate heterogeneous nucleation of grains and to decrease the hot cracking susceptibility of the material. The new Al alloy was manufactured by gas atomisation and processed by Laser Powder Bed Fusion. Samples produced with optimised parameters featured relative density of 99.91%, with no solidification cracks within their microstructure. After aging, the material revealed upper yield strength and ultimate tensile strength of 495 MPa and 460 MPa, respectively. In addition, the alloy showed tensile strength higher than wrought EN AW 2618 at elevated temperatures.


2021 ◽  
Vol 11 (24) ◽  
pp. 11833
Author(s):  
Su-Hyeon Lee ◽  
Byong-Jeong Choi

Studies involving the mechanical properties of high-strength steel (HSS) at elevated temperatures have received considerable attention in recent years. However, current research on HSS at high temperatures is lacking. As a result, the design of fire-protective steel structures with high standards is not sufficiently conservative or safe. This study investigates the effect that elevated temperatures have on the mechanical properties of ASTM A572 Gr. 50 and 60 steels. Reduction factors for the yield strength, tensile strength, and elastic modulus were derived and compared with the standard (AISC, EN1993-1-2) and previous studies (NIST). This study also provides extensive data on the reduction factors for the yield strength, tensile strength, and elastic modulus of mild steel (MS), HSS, and very-high-strength steel (VHSS). The reduction factor for the yield strength was analyzed by expanding the strain level up to 20%. Equations for the yield strength, tensile strength, and elastic modulus were proposed. In future studies, various strains should be analyzed according to the grade of the steel, with the derivation of a reduction factor that considers the plastic strain of the steel. Hence, the findings reported in this study generated a database that can be applied to fire safety design or performance-based fire-resistant design.


2019 ◽  
Vol 8 (4) ◽  
pp. 1589-1593 ◽  

The recent most admired additive manufacturing (AM) technique is the fused deposition method (FDM) because of its low cost and ease of operation. The FDM printed parts often suffered with lack of global or average strength, because of more strength in printed direction and leads to anisotropic mechanical properties. The most effective methods to obtain high tensile strength are the optimization of process parameters of FDM process to manufacture high strength Acrylonitrile Butadiene Styrene (ABS) samples. The present research paper objective is to analyze the process parameters effect on tensile strength of FDM printed specimen with ABS. The specimen is prepared as per the D638 ASTM standards. The specimens are printed in accordance with L9 matrix a Taguchi method. The chosen FDM process parameters are fill density with 40, 60 and 80(%), print speed with values of 60, 80 and 100(mm/min), and layer thickness 100, 200 and 300(microns). From the tensile strength investigation of ABS samples, the maximum tensile strength of 24.866 MPa is obtained with specimen build with the parameters, infill-80%, speed100mm/min and layer thickness 0.2mm. This proposed research work is useful to decide the effective FDM process factors and their working ranges to manufacture the ABS components or parts.


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