共查询到20条相似文献,搜索用时 15 毫秒
1.
A. Canakci 《Journal of Materials Science》2011,46(8):2805-2813
In this study, the microstructure and abrasive wear properties of varying volume fraction of particles up to 12% B4C particle reinforced 2014 aluminium alloy metal matrix composites produced by stircasting method was investigated. The density,
porosity and hardness of composites were also examined. Wear behaviour of B4C particle reinforced aluminium alloy composites was investigated by a block-on-disc abrasion test apparatus where the samples
slid against the abrasive suspension mixture (contained 10 vol.% SiC particles and 90 vol.% oil) at room conditions. Wear
tests performed under 92 N against the abrasive suspension mixture with a novel three body abrasive. For wear behaviour, the
volume loss and specific rate of the samples have been measured and the effects of sliding time and the content of B4C particles on the abrasive wear properties of the composites have been evaluated. The dominant wear mechanisms were identified
using SEM. Microscopic observation of the microstructures revealed that dispersion of B4C particles was generally uniform while increasing volume fraction led to agglomeration of the particles and porosity. The
density of the composite decreased with increasing reinforcement volume fraction but the porosity and hardness increased with
increasing particle content. Moreover, the specific wear rate of composite decreased with increasing particle volume fraction.
The wear resistance of the composite was found to be considerably higher than that of the matrix alloy and increased with
increasing particle content. 相似文献
2.
In this present work nano coconut shell charcoal (ncsc) and silicon carbide (SiC) particulates were reinforced with AZ31B Mg alloy and suitable magnesium composite was developed by using the powder metallurgy technique followed by hot extrusion. Density measurement of the Mg composites revealed that the addition of ncsc significantly improved the density of the composites and porosity measurement showed minimal porosity. The microstructure of the composites showed even distribution of the ncsc in the AZ31B/3SiC Mg composite. The compressive and impact behaviour of the samples were characterized, the results showed that on increasing the weight percentage of ncsc in AZ31B/3SiC/0.5ncsc Mg composites the mechanical properties such as ultimate compressive strength, 0.2% yield strength, ductility and impact strength decreased. The scanning electron microscope (SEM) analysis of fractured surface of AZ31B Mg alloy and AZ31B/3SiC/0.5ncsc Mg composites showed quasi-cleavage fracture. The presence of ncsc above 0.5 wt% composites revealed mixture of quasi cleavage planes and some dimples. 相似文献
3.
In this study, aluminum alloy (Al-2 wt% Cu) matrix composites reinforced with 1, 2 and 4 wt% boron carbide nanoparticles fabricated through mechanical milling with average size of 100 nm were fabricated via stir casting method at 850℃. Cast ingots of the matrix alloy and the composites were extruded at 500℃ at an extrusion ratio of 10:1 to investigate the effects of hot extrusion on the mechanical properties of the composites. The microstructures of the as-cast and the extruded composites were investigated by scanning electron microscopy (SEM). Density measurement, hardness and tensile tests were carried out to identify the mechanical properties of the composites. The extruded samples revealed a more uniform distribution of B4C nanoparticles. Also, the extruded samples had strength and ductility values superior to those of the as-cast counterparts. In the as-cast and the extruded samples, with increasing amount of B4C nanoparticles, yield strength and tensile strength increased but elongation to fracture decreased. 相似文献
4.
P. Vadivel C. Velmurugan S.J.S. Chelladurai 《Materialwissenschaft und Werkstofftechnik》2020,51(1):73-82
LM13 aluminium alloy (Al−Si12CulMg1) with titanium diboride (TiB2) and boron carbide (B4C) particulate hybrid composites have been prepared using stir casting process. Wt% of titanium diboride is varied from 0–10 and constant 5 wt% boron carbide particles have been used to reinforce LM13 aluminium alloy. Microstructure of the composites has been investigated and mechanical properties viz., hardness, the tensile strength of composites have been analyzed. Wear behavior of samples has been tested using a pin on disc apparatus under varying load (20 N–50 N) for a sliding distance of 2000 m. Fracture and wear on the surface of samples have been investigated. Microstructures of composites show uniform dispersion of particles in LM13 aluminium alloy. Hardness and tensile strength of composites increased with increasing wt % of reinforcements. Dry sliding wear test results reveal that weight loss of composites increased with increasing load and sliding distance. Fracture on the surface of composites reveals that the initiation of crack is at the interface of the matrix and reinforcement whereas dimples are observed for LM13 aluminium alloy. Worn surface of composites shows fine grooves and delamination is observed for the matrix. 相似文献
5.
I. V. Solodkyi I. I. Bogomol M. Ya. Vterkovs’kyi P. I. Loboda 《Journal of Superhard Materials》2018,40(4):236-242
This study has been the first to demonstrate the possibility of producing boron carbide ceramics from coarse (D = 25–150 μm) B4C powder (which is impossible to sinter by conventional methods) through infiltration with molten silicon and subsequent treatment within the field of the controlled temperature gradient. This produces yields a composite ceramics B4C–SiC–Si with a hardness of 26 to 35 GPa and a splitting tensile strength of 110 to 170 MPa. The influence of the velocity of movement of the temperature gradient on the structure, phase composition, and properties of the prepared composites has been studied. 相似文献
6.
The B4C/BN composites were fabricated by hot-pressing process. In this research, the silicon infiltration process was applied to improve the surface hardness and wear resistance of the B4C/BN composites. The phase composition, microstructure, Vickers hardness and wear resistance of the silicon infiltrated B4C/BN composites were investigated and compared with the hot-pressed B4C/BN composites. XRD analysis results of the silicon infiltrated specimens showed that the resultant coating was mainly composed of silicon carbide and silicon. The Vickers hardness of the silicon infiltrated B4C/BN composites was significantly improved in comparison with the hot-pressed B4C/BN composites. The Vickers hardness of the silicon infiltrated B4C/BN composites achieved to 12-16 GPa. The wear resistances of the silicon infiltrated B4C/BN composites were also significantly improved in comparison with the hot-pressed B4C/BN composites. SEM micrograph of silicon infiltrated specimens showed that the thickness of silicon carbide and silicon coating was about 200-300 μm, which significantly improved the surface hardness and wear resistance of the B4C/BN composites. 相似文献
7.
Wang Honglei Zhou XinguiYu Jinshan Cao YingbinLiu Rongjun 《Materials Science and Engineering: A》2011,528(6):2441-2445
Three-dimensional (3D) KD-1 silicon carbide fiber reinforced silicon carbide matrix (KD-1 SiCf/SiC) composites were fabricated by a combining chemical vapor infiltration (CVI) and vapor silicon infiltration (VSI) process. The microstructure and mechanical properties of the resulting KD-1 SiCf/SiC composites were studied. The results show that the resulting SiCf/SiC composites have high bulk density and low open porosity (<6%). The mechanical properties of the resulting SiCf/SiC composites firstly increase and then decrease with decreasing the open porosity of the SiCf/C composites. The KD-1 SiC fibers were not severely deformed and adhered to the matrix with a weak interface during the VSI process. As a result, the composites exhibit non-catastrophic failure behavior. Additionally, the diffusion mechanism for the VSI process was also investigated in our work. 相似文献
8.
This work focuses on the fabrication of aluminum (6061-T6) matrix composites (AMCs) reinforced with various weight percentage of B4C particulates by modified stir casting route. The wettability of B4C particles in the matrix has been improved by adding K2TiF6 flux into the melt. The microstructure and mechanical properties of the fabricated AMCs are analyzed. The optical microstructure and scanning electron microscope (SEM) images reveal the homogeneous dispersion of B4C particles in the matrix. The reinforcement dispersion has also been identified with X-ray diffraction (XRD). The mechanical properties like hardness and tensile strength have improved with the increase in weight percentage of B4C particulates in the aluminum matrix. 相似文献
9.
P. Ashwath 《Materials and Manufacturing Processes》2018,33(1):7-12
Metal matrix composites (MMCs) using Aluminum Alloy 2900 and 2024 as matrix material with silicon carbide and alumina as reinforcement have been fabricated through powder metallurgy route for investigation. The average particle size of matrix metal and reinforcement material considered in this research is 10?µm. AA-SiC and AA-Al2O3 composites with 3, 6, and 9 weight percentage (wt%) of SiC and Al2O3 are fabricated. The Rockwell hardness and Compressive strength of AA-SiC and AA-Al2O3 composites were found to increase with an increase in the wt% of reinforcement when the samples were microwave sintered. AA 2024 with 6?wt% Al2O3 reinforced MMCs samples were exhibiting improved hardness results, strength behavior, and stress-strain behavior when the samples are microwave sintered. AA 2900 with 6?wt% Al2O3 exhibited good ductility and formability properties. Good Microstructural bonding was observed in the MMCs, which is attributed to finer Al2O3 particulate used as reinforcement and the microwave sintering. 相似文献
10.
Honglei Wang Xingui Zhou Jinshan Yu Yingbin Cao Rongjun Liu 《Materials Letters》2010,64(15):1691-1693
Three-dimensional (3D) silicon carbide fiber reinforced silicon carbide matrix (SiCf/SiC) composites, employing KD-1 SiC fibers (from National University of Defense Technology, China) as reinforcements, were fabricated by a combining chemical vapor infiltration (CVI) and vapor silicon infiltration (VSI) process. The microstructure and properties of the as prepared SiCf/SiC composites were studied. The results show that the density and open porosity of the as prepared SiCf/SiC composites are 2.1 g/cm3 and 7.7%, respectively. The SiC fibers are not severely damaged during the VSI process. And the SiC fibers adhere to the matrix with a weak interface, therefore the SiCf/SiC composites exhibit non-catastrophic failure behavior with the flexural strength of 270 MPa, fracture toughness of 11.4 MPa·m1/2 and shear strength of 25.7 MPa at ambient conditions. Moreover, the flexural strength decreases sharply at the temperature higher than 1200 °C. In addition, the thermal conductivity is 10.6 W/mk at room temperature. 相似文献
11.
A. Sakthivel R. Palaninathan R. Velmurugan P. Raghothama Rao 《Journal of Materials Science》2008,43(22):7047-7056
In this study, 2618 aluminum alloy metal matrix composites (MMCs) reinforced with two different sizes and weight fractions
of SiCp particles upto 10% weight were fabricated by stir cast method and subsequent forging operation. The effects of SiCp particle content and size of the particles on the mechanical properties of the composites such as hardness, tensile strength,
hot tensile strength (at 120 °C), and impact strength were investigated. The density measurements showed that the samples
contained little porosity with increasing weight fraction. Optical microscopic observations of the microstructures revealed
uniform distribution of particles and at some locations agglomeration of particles and porosity. The results show that hardness
and tensile strength of the composites increased, with decreasing size and increasing weight fraction of the particles. The
hardness and tensile strength of the forged composites were higher than those of the cast samples. 相似文献
12.
《Materials Science & Technology》2013,29(7):823-832
AbstractIn the present study, elemental magnesium and magnesium–silicon carbide composites were synthesised using the methodology of fluxless casting followed by hot extrusion. Microstructural characterisation studies revealed low porosity and a completely recrystallised matrix in every material. The average size of the recrystallised grains was found to decrease with an increasing presence of SiC particulates. For the reinforced magnesium, fairly uniform distribution of SiC particulates and good SiC–Mg interfacial integrity was realised. The results of X-ray diffraction studies indicated the absence of oxide phases and no evidence of interfacial reaction products except in the case of Mg–26.0 wt-%SiC sample. Results of physical and mechanical properties characterisation revealed that an increase in the amount of SiC particulates incorporated leads to an increase in macrohardness and elastic modulus, which does not affect the 0.2% yield strength and reduces the ultimate tensile strength, ductility, and coefficient of thermal expansion. The weight percentage of SiC particulates when plotted against hardness and 0.2% yield strength revealed a linear correlationship. An attempt is made to investigate the effect of increasing amount of SiC particulates on the microstructural features, and physical and mechanical properties of the magnesium matrix. 相似文献
13.
W.S. Yang S. Biamino E. Padovano L. Fuso M. Pavese S. Marchisio D. Vasquez C. Vega Bolivar P. Fino C. Badini 《Composites Science and Technology》2012
Silicon carbide multilayer composites containing short carbon fibres (Csf/SiC) were prepared by tape casting and pressureless sintering. The C fibres were dispersed in solvents with dispersant (Triton X-100) firstly and then mixed with the SiC slurry to make green Csf/SiC tapes. Fibres were homogeneously distributed in the tape and tended to align fairly well along the tape casting direction. The addition of short C fibre hindered the shrinkage in the plane containing the fibres as well as the grain growth of SiC during sintering. The weight loss occurring during oxidation tests of Csf/SiC multilayer composites increased with fibre amount and material porosity. Elastic modulus of Csf/SiC multilayer composites decreased linearly with fibre amount. Bending strength presented clear relationship with the relative density, that is with the total porosity. 相似文献
14.
Recycled polypropylene (RPP) based hybrid composites of date palm wood flour/glass fibre were prepared by different weight ratios of the two reinforcements. Mixing process was carried out in an extruder and samples were prepared by injection molding machine. Recycled PP properties were improved by reinforcing it by wood flour. The tensile strength and Young’s modulus of wood flour reinforced RPP increased further by adding glass fibre. Glass fibre reinforced composites showed higher hardness than other composites. Morphological studies indicated that glass fiber has good adhesion with recycled PP supporting the improvement of the mechanical properties of hybrid composites with glass fiber addition. Addition of as little 5 wt% glass fibre to wood flour reinforced RPP increases the tensile strength by about 18% relative to the wood flour reinforcement alone. An increase in wood particle content in the PP resulted in a decrease in the degree of crystallinity of the polymer. The tensile strength of the composites increased with an increase in the percentage of crystallinity when adding the glass fibre. The improvement in the mechanical properties with the increase in crystallinity percentage (and with the decrease of the lamellar thicknesses) can be attributed to the constrained region between the lamellae because the agglomeration is absent in this case. 相似文献
15.
The effects of SiC and B4C additives in the MoSi2 matrix on the microstructures and mechanical properties at room temperature were investigated. Their coefficients of thermal expansion (CTE) were also evaluated up to 1200°C by a thermal mechanical analysis (TMA). The experimental results show that the Mo2B5 reinforced phase was formed in situ in the hot-pressed MoSi2/SiC/B4C composites. Both the Mo2B5 phase and the SiC phase significantly improved the mechanical behavior of MoSi2. Besides, the SiC with a high content up to 40 vol% could be added into the MoSi2 composite with the B4C additive. As a result, a dense and homogenous MoSi2/SiC/B4C composite was obtained, which possessed a relatively high bending strength and fracture toughness. Meanwhile, the CTE of the MoSi2/SiC/B4C composites linearly decreased with the increasing SiC content, which dropped to 21% at 1200°C in comparison with the pure MoSi2 when adding 40 vol% SiC. This MoSi2/SiC/B4C composite system is very important for developing new applications at elevated temperature, particularly for high-temperature coating applications. 相似文献
16.
The present research work emphasizes the development of hybrid aluminum (AA6082) matrix composites (HAMCs) reinforced with different weight percentages (wt.%) of ball-milled (silicon nitride (Si3N4) + graphite (Gr)) ceramic particulates by conventional stir casting process. Si3N4 and Gr are ball milled to obtain a definite density of combined powder. The weight percentage of ball-milled ceramic powder is varied from 0 to 12 wt.% in a stage of 3%. The microstructures as well as mechanical properties of the fabricated hybrid composites are analyzed. The scanning electron micrograph reveals the uniform distribution of ball-milled (Si3N4 + Gr) ceramic particulates in the aluminum matrix. The distribution of ball-milled (Si3N4 + Gr) ceramic particulates has also been analyzed with x-ray diffraction (XRD) technique. Both the hardness and ultimate tensile strength have enhanced with a reduction in percentage elongation with increase in weight percentage of ball-milled (Si3N4 + Gr) ceramic particulates in the aluminum matrix. 相似文献
17.
Process and wear behavior of monolithic SiC and short carbon fiber-SiC matrix composite 总被引:1,自引:0,他引:1
The process and wear behavior of monolithic SiC and 10 vol. % short carbon fiber-SiC matrix (C-SiC) composite have been studied. The results indicate that, among ethyl alcohol, acetone, n-hexane and n-octyl alcohol, n-octyl alcohol was the most effective dispersing agent in dispersing both SiC powder and short carbon fiber. Among AlN, Al2O3, B4C, graphite, AlN/B4C, AlN/graphite, B4C/graphite and Al2O3/B4C, the most effective sintering aid for the fabrication of SiC and C-SiC composite was a mixture of 2 wt% AlN and 0.5 wt% graphite. The monolithic SiC hot-pressed at 2100°C exhibited higher density but lower flexural strength than those hot-pressed at 2000°C due to a grain growth effect. For the C-SiC composite, both density and strength of the composite hot-pressed at 2100°C were generally higher than those hot-pressed at 2000°C. The density and strength of C-SiC composite were lower than those of monolithic SiC under the same hot pressing conditions due to a higher porosity level in the composite. When monolithic SiC slid against C-SiC composite, the weight losses of SiC and the composite were each less than that of self-mated SiC or self-mated C-SiC. In the self-mated SiC tribosystem, a mechanically stable film could not be established, resulting in an essentially constant wear rate. When sliding against C-SiC, a thin, smooth and adherent debris film was quickly formed on the SiC surface, resulting in a lower wear. 相似文献
18.
Boron carbide-silicon carbide ceramic composites are very promising armor materials because they are intrinsically very hard.
However, their fracture toughness is not very high. Their ballistic performance could be significantly increased if the brittleness
of these materials could be decreased. Here we report development of boron carbide-silicon carbide layered ceramics with controlled
compressive and tensile stresses in separate layers. Such B4C-SiC laminates with strong interfaces can provide high apparent fracture toughness and damage tolerance along with high protection
capabilities.
The theory of heterogeneous layered systems was used to develop optimal design parameters allowing the evaluation and maximization
of apparent fracture toughness. The layered composites were designed in a way to achieve high compressive residual stresses
in thin B4C-SiC based layers and low tensile residuals stresses in thick B4C layers. The residual stresses were controlled by the phase composition of layers and the layers thickness. The estimated
apparent fracture toughness was calculated for both three layered and nine layered composites. B4C-30 wt%SiC/B4C laminates were made based on the optimized design for high apparent fracture toughness. Processing of laminates involved
preprocessing of powders, forming green tapes and hot pressing. Work is in progress to measure fracture toughness of laminates,
as well as their strength, hardness and the ballistic performance. 相似文献
19.
碳纤维增强的纳米碳化硅陶瓷基复合材料力学性能优良,且具有一定的生物相容性,因此可作为一种新型的可取代钛合金的全尺寸整体人工骨骼。研究了具有三向正交结构的T300和M30碳纤维预制体对C/SiC复合材料制备过程和抗弯强度的影响规律。以聚碳硅烷为先驱体,以二乙烯基苯为溶剂和交连剂,采用聚合物浸渍热解法制备了C/SiC复合材料,采用阿基米德排水法测量其密度和气孔率,采用三点抗弯法测量其抗弯强度。M30 C/SiC抗弯强度比T300 C/SiC高6.7%,表明碳纤维弹性模量对复合材料基体开裂强度有显著影响,并通过增加纤维径向强度以及承担载荷的比例提高了复合材料的断裂强度。 相似文献
20.
S.J.S. Chelladurai T. Murugesan T. Rajamani S. Anand S.J.P. Asok S. Kumaravel 《Materialwissenschaft und Werkstofftechnik》2019,50(7):864-874
LM13 aluminium alloy with boron carbide (0 wt.%–7.5 wt.%) and fly ash (2.5 wt.%) reinforced particulate hybrid composites were fabricated using liquid metallurgy route. Microstructure and mechanical properties viz., hardness, ultimate tensile strength and ductility were investigated. Wear behaviour of composites was tested by varying sliding distance and load. Fracture surface and worn surface of composites were examined using field emission scanning electron microscope. Microstructure of hybrid composites revealed uniform dispersion of particles in LM13 aluminium alloy. Hardness and tensile strength of composites increased with increasing wt.% of boron carbide and fly ash particles. Wear test results showed that addition of particles significantly decreased the weight loss and coefficient of friction. Also cumulative weight loss decreased up to 47.2 % for 10 wt.% of hybrid composites as compared to LM13 aluminium alloy. Fracture surface of composites showed dimples with particle cracking on the surface. Worn surface of LM13 aluminium alloy showed continuous grooves due to ploughing with delamination. However, worn surface of composites showed fine grooves due to the presence of hard reinforcements on the surface. Boron carbide and fly ash reinforced LM13 aluminium hybrid composites exhibited superior mechanical properties with excellent wear resistance as compared to LM13 aluminium alloy. 相似文献