Preparation of Sialon/Si3N4-SiC Composite Refractories Using Kyanite Tailings

2016 ◽  
Vol 697 ◽  
pp. 467-471 ◽  
Author(s):  
Ming Hao Fang ◽  
Zhao Hui Huang ◽  
Yan Gai Liu ◽  
Xin Min ◽  
Li Na Zhang
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Cross Section ◽  
Compression Strength ◽  
Carbothermal Reduction ◽  
Bending Strength ◽  
Synthesis Temperature ◽  
Composite Powders ◽  
Excess Carbon ◽  
Sic Composites

Sialon-SiC composite powders were synthesized from kyanite tailings through the carbothermal reduction nitridation (CRN) technique. Using Sialon-SiC composites to substitute Si3N4 composites via the CRN technique synthesize Sialon/Si3N4-SiC composite refractories. The phase composition, cross section morphology, and the substituent amount of Sialon-SiC composites impact on refractories mechanical properties were investigated, respectively. The optimized synthesis temperature for the CRN reaction was found to be 1550 °C for 4 h with the excess carbon 20%. The substituent amount of Sialon-SiC was 25%, the mechanical properties of Sialon/Si3N4-SiC composite refractories reached optimal performance, which bending strength value was 41.8 MPa and compression strength value was 61.6 MPa.

Effects of CaO Additives on the Phase Evolution of ZrO2-SiC Composites from Zircon by Carbothermal Reduction

2014 ◽  
Vol 602-603 ◽  
pp. 105-109
Author(s):  
Ze Lin Wu ◽  
Ming Hao Fang ◽  
Zhao Hui Huang ◽  
Yan Gai Liu ◽  
You Guo Xu ◽  
...  
Keyword(s):  
Phase Composition ◽  
Composite Materials ◽  
Carbothermal Reduction ◽  
Reduction Process ◽  
Phase Evolution ◽  
Synthesis Temperature ◽  
Raw Material ◽  
Natural Zircon ◽  
Synthetic Temperature ◽  
Sic Composites

In this study, Ca2+ stabilized ZrO2-SiC composite materials were prepared via carbothermal reduction, using natural zircon ore as raw material, CaO as additive, and black carbon as the reducing agent. The effects of synthesis temperature and CaO content on the phase composition of the products were investigated by XRD. The microstructure and micro-area chemical analysis of the products were characterized by SEM and EDS. The results indicate that: (1) Ca2+ stabilized ZrO2-SiC composite materials could be prepared from natural zircon ore with CaO addition between 1500°C and 1600°C for 4 hours by carbothermal reduction process. (2) The synthetic temperature has an important influence on the phase composition of the carbothermal reduction products of zircon. The production of m-ZrO2 and t-ZrO2 got obviously enhanced with increasing temperature from 1500°C to 1600°C. (3) At the same synthetic temperature, Ca2+ stabilized ZrO2 got enhanced with increasing adding amount of CaO. The optimized synthesis condition of Ca2+ stabilized cubic-ZrO2/SiC composite materials is sintering at 1600°C for 4 hours with adding 40 mol% CaO as additive.

scholarly journals Sintering Behavior and Mechanical Properties of Mullite Fibers/Hydroxyapatite Ceramic

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1859 ◽  
Author(s):  
Xueni Zhao ◽  
Qingyao Liu ◽  
Jianjun Yang ◽  
Weigang Zhang ◽  
Yao Wang
Keyword(s):  
Mechanical Properties ◽  
Hydrothermal Synthesis ◽  
Bending Strength ◽  
Fiber Content ◽  
Silicate Glasses ◽  
Sintering Behavior ◽  
Composite Powders ◽  
Hydroxyapatite Ceramic ◽  
Dense Microstructure ◽  
Mullite Fibers

The effect of fiber content and sintering temperature on sintering behavior and mechanical properties of mullite fibers/hydroxyapatite composites was studied. The composites were fabricated by hydrothermal synthesis and pressureless sintering. The amount of fibers was varied from 5 wt % to 15 wt % through hydrothermal synthesis, mullite fibers and hydroxyapatite composite powders were subsequently sintered at temperatures of 1150, 1250, and 1350 °C. The composites presented a more perturbed structure by increasing fiber content. Moreover, the composites experienced pore coalescence and exhibited a dense microstructure at elevated temperature. X-ray diffraction indicated that the composites underwent various chemical reactions and generated silicate glasses. The generation of silicate glasses increased the driving force of particle rearrangement and decreased the number of pores, which promoted densification of the composites. Densification typically leads to increased hardness and bending strength. The study proposes a densification mechanism and opens new insights into the sintering properties of these materials.

Preparation and Characterization of Fe/SiC Ceramic-Metal Composites

2010 ◽  
Vol 434-435 ◽  
pp. 66-68 ◽  
Author(s):  
Zhong Sheng Liu ◽  
Gang Shao ◽  
De Liang Chen ◽  
Rui Zhang
Keyword(s):  
Bending Strength ◽  
Low Cost ◽  
High Hardness ◽  
High Strength ◽  
Precipitation Method ◽  
High Wear Resistance ◽  
Matrix Composites ◽  
Composite Powders ◽  
Pressing Method ◽  
Sic Composites

SiC is a perfect reinforced material, characteristic of high hardness, high wear- and corrosion-resistant property, and low cost. SiC-reinforced iron-matrix composites show high wear resistance, high hardness, high inflexibility and high strength, with wide applications as superior wear-resistant and high temperature materials. This paper reported a heterogeneous precipitation method to coat SiC with copper particles. The vacuum hot-pressing method was used to sinter the Fe/SiC composites with Cu-coated SiC powders. The techniques of XRD and SEM were used to characterize the compositions and microstructures of the samples. The Archimedes method was used to test the density. The results showed that SiC and Cu were homogeneously mixed in the composite powders obtained by the heterogeneous deposition method, and that the composites with 5wt% of SiC (Cu) obtained at 950°C have a high relative density of 96%, a high hardness of 4121 MPa and a high bending strength of 646 MPa. The enhanced properties of Fe/SiC composites could result from the improved interfacial consistency by using Cu-coated SiC powders, which could inhibit some adverse interfacial reactions.

Effect of Ni Coated SiC on Mechanical Properties of SiC/Fe Composites

2014 ◽  
Vol 602-603 ◽  
pp. 578-581
Author(s):  
Bin Bin Wang ◽  
Bing Bing Fan ◽  
Wen Li ◽  
Chen Yang Wang ◽  
Bing Sun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Chemical Deposition ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Structure Morphology ◽  
Chemical Deposition Method ◽  
Shell Composite ◽  
Electronic Microscope

A facile onestep in situ chemical deposition method was introduced to synthesize Ni coated SiC composite powders, which used NiCl2·6H2O as nickel source and N2H4·H2O as reductant, respectively. SiC(Ni)/Fe composites were prepared by current-vacuum hot-pressed sintering at 850°C, 40MPa for 30min. Scanning electronic microscope (SEM) and X-ray diffraction (XRD) were used to characterize the structure, morphology and composition of the prepared Ni/SiC core/shell composite powders. It is found that the Ni coated SiC is favorable to improve the dispersion and compatibility of SiC(Ni)/ Fe composites. By a series of contrast experiments, it is shown that the sintering sample with 5wt% of SiC(Ni) has the best mechanical properties. The relative density, Vickers hardness and bending strength is 91.67%, 4.72GPa and 508MPa, respectively.

scholarly journals Mechanical Properties of Laminated Veneer Lumber Beams Strengthened with CFRP Sheets

2019 ◽  
Vol 65 (2) ◽  
pp. 57-66 ◽  
Author(s):  
M. Bakalarz ◽  
P. G. Kossakowski
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Bending Strength ◽  
Carbon Fabric ◽  
Static Work ◽  
Work Analysis ◽  
Cfrp Sheets ◽  
Laminated Veneer Lumber ◽  
Frp Reinforcement ◽  
Bottom Face

AbstractThis paper presents the results of the static work analysis of laminated veneer lumber (LVL) beams strengthened with carbon fabric sheets (CFRP). Tested specimens were 45mm wide, 100 mm high, and 1700 mm long. Two types of strengthening arrangements were assumed as follows: 1. One layer of sheet bonded to the bottom face; 2. U-shape half-wrapped reinforcement; both sides wrapped to half of the height of the cross-section. The reinforcement ratios were 0.22% and 0.72%, respectively. In both cases, the FRP reinforcement was bonded along the entire span of the element by means of epoxy resin. The reinforcement of the elements resulted in an increase in the bending strength by 30% and 35%, respectively, as well as an increase in the global modulus of elasticity in bending greater than 20% for both configurations (in comparison to the reference elements).

Effect of Needling Parameters on Mechanical Properties of C/C Composites Reinforced by Carbon Cloth

2007 ◽  
Vol 546-549 ◽  
pp. 1521-1524
Author(s):  
Xiao Hu Zhang ◽  
He Jun Li ◽  
Zhi Biao Hao ◽  
Hong Cui
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Strength ◽  
Compression Strength ◽  
Bending Strength ◽  
Interlaminar Shear Strength ◽  
Carbon Cloth ◽  
Depth Range ◽  
Needle Punching ◽  
Interlaminar Shear

The influence of needling parameters on mechanical properties of carbon-carbon (C-C)composites reinforced by needled carbon cloth was studied in the present investigation. The results showed that needling density (ND)and needle-punching depth (PD) both had a larger effect on interlaminar shear strength (ILSS) than on compression strength and flexible strength of Needling C-C(NC-C). The mechanical properties of NC-C increased with increasing punching density in the range of 20-45 punch/cm2 and also with increasing punching depth range from10 to16mm. The NC-C with the highest ND value of 55punch/cm2 had highest ILSS value of 27 MPa.The optimized ND and PD parameters was 30 punch/cm2 and 12mm respectively, which resulted in a high value of tensile strength(119MPa), bending strength (220MPa) and compression strength (235 MPa) in the X-Y direction .

scholarly journals Effects of modification with glutaraldehyde on the mechanical properties of wood

Holzforschung ◽  
2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Zefang Xiao ◽  
Yanjun Xie ◽  
Holger Militz ◽  
Carsten Mai
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Scots Pine ◽  
Compression Strength ◽  
Bending Strength ◽  
Weight Percent Gain ◽  
Strength Loss ◽  
Modulus Of Rupture ◽  
Finite Span ◽  
Decreasing Ph

Abstract Scots pine (Pinus sylvestris L.) sapwood was treated with glutaraldehyde (GA) and magnesium chloride (MgCl2) as a catalyst. The effects of treating conditions on the mechanical properties were examined. The weight percent gain (WPG) of thin veneer strips after leaching was highest at pH 4.0–4.5 and tensile strength measured in zero-span strength and finite-span strength decreased with decreasing pH in a range of 3.5–5.5. Sole treatment with MgCl2 also gradually decreased the tensile strength up to 25% with decreasing pH. At a fixed GA concentration (1.2 M), increasing MgCl2 concentration linearly diminished tensile strength. Conversely, increasing GA at a fixed MgCl2 concentration (1.5%) displayed the same effect, whereas in both cases zero-span strength loss was higher than finite span-strength loss. GA treatment of Scots pine sapwood stakes did not affect the modulus of rupture and the modulus of elasticity, but significantly reduced work to maximum load in bending and impact bending strength indicating embrittlement of wood. At the same time, compression strength increased with increasing WPG of GA. It is assumed that embrittlement caused by hydrolysis and crosslinking of cell wall polymers is compensated by enhanced compression strength thereby resulting in unchanged bending strength.

The Microstructures and Mechanical Properties of Molybdenum Disilicide Preforms Infiltrated by Aluminum

2006 ◽  
Vol 317-318 ◽  
pp. 331-334 ◽  
Author(s):  
Xiao Li Zhang ◽  
Zhi Hao Jin ◽  
Zhen Lin Lu
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Bending Strength ◽  
Molybdenum Disilicide ◽  
Experimental Results ◽  
Reactive Infiltration ◽  
Infiltration Temperature ◽  
N2 Atmosphere ◽  
Different Temperatures ◽  
High Infiltration

Infiltrant aluminum was infiltrated into molybdenum disilicide preforms in N2 atmosphere at different temperatures by liquid reactive infiltration processing. The mechanical properties and phase composition of these materials were analyzed and discussed. The experimental results showed that the samples were corresponding to 10 at.% Al averagely after sintered, and consisted of Mo(Al,Si)2 phase and Al-Si alloy phase. High infiltration temperature would lead to Al deficiency mainly in Al-Si alloy phase. The highest bending strength of 737 MPa was reached at infiltration temperature of 1350 °C because the sample had fine and integrated grains, and the strong combination between particles. When the infiltration temperature was higher than 1350 °C, the bending strength of material prepared would decrease because of the phase fragmentation.

Effect of Braided Structure on Mechanical Properties of Cf/SiC Composites

2012 ◽  
Vol 538-541 ◽  
pp. 423-426
Author(s):  
De Ke Zhang ◽  
Ying Bin Cao ◽  
Rong Jun Liu ◽  
Ya Nan Jiao
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Microstructure And Properties ◽  
Braided Structure ◽  
Sic Composites ◽  
Change Tendency

Using polycarbosilane(PCS) as precursor materials, 2.5D、3D3d、3D4d、3D5d braided structure Cf/SiC composites were prepared by Precursor Infiltration and Pyrolysis (PIP). The result showed that different braided structure Cf/SiC composites had dissimilar change tendency of density and porosity. The braided structure and pore position influenced mechanical properties of Cf/SiC composites obviously. 2.5D Cf/SiC composites had the lowest mechanical properties compared others braided structure via PIP process, 3D5d Cf/SiC composites had the highest mechanical properties for the bending strength reached 334MPa, modulus 99.5GPa. Furthermore, the microstructure and properties of different braided structure Cf/SiC composites has been investigated by means of SEM.

scholarly journals Wood Quality Characterization of Sycamore Maple (Acer pseudoplatanus L.) and its Utilization in Wood Products Industries

2021 ◽  
Vol 42 (3) ◽  
Author(s):  
Tomislav Sedlar ◽  
Bogoslav Šefc ◽  
Srđan Stojnić ◽  
Tomislav Sinković
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Wood Quality ◽  
Beech Wood ◽  
Wood Products ◽  
Dry Density ◽  
Acer Pseudoplatanus ◽  
Sycamore Maple

This study quantified the physical and mechanical properties of sycamore maple (Acer pseudoplatanus L.) as a basis for assessing wood quality. The physical properties of oven-dry density, density at 12% MC, green density, basic density, longitudinal, radial, tangential and volumetric shrinkages were tested and the mechanical properties of bending strength, modulus of elasticity at bending, compression strength parallel to grain and compression strength in radial and tangential direction as well as of Brinell hardness on the cross, radial, and tangential section were determined. Five sycamore maple trees from Medvednica region were selected for the purposes of this research. The results were compared with known literature data on sycamore maple wood, beech wood from the same sight, and beech wood from Gorski Kotar region. For a better understanding of sycamore maple physiology, as well as for assessing the quality of wood products, the distribution of wood properties within the tree radius, from pith to bark, was investigated. There was a general bell shaped distribution, in the radial direction, in wood density, and mechanical properties of sycamore maple wood. Shrinkages decreased from pith to bark, except for tangential shrinkage with bell shaped pattern. All investigated wood densities of sycamore maple from Medvednica were similar to the findings of studies known in literature, as well as shrinkages, except for the lower longitudinal shrinkage. Investigated mechanical properties of sycamore maple wood were similar to the findings of studies known in literature, except for the lower bending strength and modulus of elasticity (MOE). Investigated sycamore maple indicated better dimensional stability than beech wood from two locations in the region, although it did not match the beech wood regarding mechanical properties, especially wood hardness.

Sign in / Sign up

Export Citation Format

Share Document