Processing and mechanical properties of B4C reinforced Al matrix composites (original) (raw)
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Science of Sintering, 2018
In this study, powders of Al 1070 and B4C were prepared by volume in three different reinforcement ratios 4 % B4C, 8 % B4C and 16 % B4C compacted under the pressure of 500 MPa with cold pressing method then sintered under the temperatures of 500, 550 and 600 oC. Then the hardness was measured and wear test was performed using the pin-on-disk method. In the results of tests, the compression pressure of 500 MPa was not sufficient for composite structure to achieve the required density. The highest hardness values were achieved at a sintering temperature of 550 oC and in 8 % B4C reinforced composite. The highest wear rate was measured in 4 % B4C reinforced composite specimen sintered at 600 oC. It is determined that a sintering temperature above 550 oC had adverse effects on the mechanical properties.
Powder Metallurgy and Metal Ceramics, 2019
The conversion into the desired shape of the metal powders using Powder Metallurgy (PM) method enables economically mass productions. This case allows producing parts with complex and high dimensional accuracy with no machining. In this study the composites and hybrid composites with Al matrix were produced using PM method with different ratios B 4 C and SiC. Microhardness and wear experiments of the produced composites were investigated. Wear experiments were performed at a constant speed of 0.5 m/s, application loads of 5, 10 and 15 N and sliding distances of 250, 500, and 750 m. Then, SEM images of composites and hybrid composites were captured. The increase of the reinforcement ratio in the composites contributed to the increase of the hardness. The highest hardness value was computed as 58.7 HV from 16% B 4 C reinforced composite. In addition, the increase in the reinforcement ratio contributed to the increase of the wear resistance. The increase in the load and sliding distance also increased the wear. The minimum weight loss was calculated as 18 mg from 5 N load, 250 m sliding distance and 16% SiC reinforced composite.
Materials Today: Proceedings, 2019
This paper reviews different experimental and theoretical studies related to B4C reinforced aluminum metal matrix composites (MMC). Various processes like solid sintering, powder processing through ball milling, and also various thermo-mechanical processing like heat treatment, quenching are discussed. The effects on the particle size of boron carbide (B4C) reinforcement on morphology evolution and microstructure are thoroughly studied. The strengthening mechanisms of B4C reinforced Al-MMC are thoroughly reviewed and the interfacial structure in between B4C and matrix material are discussed.
Hardness and tensile strength study on Al356–B4C composites
Additions of high modulus particles to aluminium alloys offer the potential to develop a lightweight composite with high strength and hardness. Al356 matrix composites reinforced with B 4 C particles were prepared using stir casting method. Hardness and tensile strength of unreinforced alloy and composites with different volume percentages of boron carbide particles were measured and compared. Microstructural characterisation revealed an almost uniform distribution of the B 4 C particles in the matrix. It also showed that the grain size of aluminium composite is smaller than that of monolithic aluminium. X-ray diffraction studies also confirmed the existence of boron carbide and some other reaction products, such as AlB 2 and Al 3 BC, in composite samples. It is observed that the mechanical properties enhance with increasing particle fraction. The great enhancement in values of ultimate tensile stress and hardness observed in this experiment is due to small particle size and good distribution of the B 4 C particles, which was confirmed by SEM images. According to the results of this experiment, quite significant improvement in strength is noted when 10 vol.-%B 4 C particles is added; a further increase in B 4 C content leads to a reduction in strength values. This might be the result of greater agglomeration of particles and higher degree of microporosity present in the composite at higher B 4 C content.
Effect of distribution of B4C on the mechanical behaviour of Al-6061/B4C composite
Powder Metallurgy, 2018
In this work, the effect of mixing parameters on the distribution of B 4 C in 6061-Al alloy and its correlation with mechanical behaviour was studied. 6061-Al alloy powder was mixed with 10 mass-% B 4 C powder in a ball mill and powder rotator mixer by varying mixing time from 1 to 5 h. Mixing was performed in both wet and dry conditions in a ball mill while only dry condition was used in the powder rotator mixer. The green compacts were sintered at 630°C. The quadrat method was used to quantify the distribution of B 4 C particles in the microstructures of sintered Al/B 4 C composite. The results showed that the distribution was improved with mixing time but the density, hardness and compression strength of Al/B 4 C composites were reduced with time during ball milling. On the other hand, the distribution of reinforcement, density, hardness and compressive strength of Al/B 4 C composites was improved with mixing time in the powder rotator mixer.
Currently aluminum metal matrix composites (MMC) with particulate reinforcement and related manufacturing methods are among important research topics because of their low density, high specific stiffness, strength, and wear resistance. B 4 C p /Al composites are commonly used materials for fabrication of lightweight functional components. Different percentage amounts of B 4 C p (3wt%, 6wt%, and 9wt%) were added to the aluminum matrix and the composite materials were prepared at 823 °K under argon atmosphere. The X-ray diffraction (XRD) showed the formation of the phases such as Al, B 4 C and AlB 2 in B 4 C p /Al composites. The density of the composite materials decreased from 2.5773 to 2.5270 g/cm 3 with an increase in the amount of B 4 C p addition. The optimum properties (hardness and compressive strength) were obtained by reinforcement with smallest B 4 C particles (size 22 µm). The present work was concentrated on the feasibility of the fabrication of B 4 C p particulate reinforced aluminum MMCs by P/M technique.
Aluminum Matrix Composites (AMCs) are emerging as advance engineering materials due to their strength, ductility and toughness. The aluminium matrix can be strengthened by reinforcing with hard ceramic particles like SiC,Al 2 O 3 , B 4 C etc.In this work The aim involved in designing metal matrix composite materials is to combine the desirable attributes of metals and Ceramics.Powder metallurgy is one of the established manufactured processes which allow products of complex geometries to be produced with tailor made properties like high strength and tolerances. P/M has replaced conventional metal forming operations due to added benefits like high material utilization, low energy consumption, less material wastage and reasonable cost, because of which it is extensively used in automobile, aerospace and many other industriesIn this work Al7075-Sic and Al6082-B 4 C metal matrix composites were fabricated using powder metallurgy technique Specimens were prepared by varying reinforcement...
Journal of Materials Processing Technology, 2003
Three aluminium metal matrix composites containing reinforcing particles of B 4 C, SiC and Al 2 O 3 (0-20 vol. %) were processed. The stir-casting manufacturing route followed by hot extrusion was utilized, being one of the cost-effective industrial methods. In this study, the feasibility of processing B 4 C reinforced Al composite was investigated and a comparison was made with the other two composites. The microstructural distribution of reinforcing particles in all three composites was studied by means of optical and scanning electron microscopy (SEM). The distribution and chemical composition of the phases formed at matrix/particulate interface of the processed composites were also investigated by SEM and energy dispersive x-ray spectroscopy (EDX). A clear interfacial reaction product/layer was found at Al/SiC interface for composites held for a relatively long processing time (> 30 minutes). No reaction product was observed at Al/B 4 C and Al/Al 2 O 3 interfaces at the resolution limit of the SEM used. On the other hand, two secondary phases (alumina and another phase containing aluminium, boron and carbon) were found in the aluminum matrix away from the interface in Al-B 4 C composites. From the fracture surface analysis, B 4 C reinforced Al composite seemed to exhibit a better interfacial bonding compared to the other two composites.
High Temperature Mechanical Properties and Wear Performance of B4C/Al7075 Metal Matrix Composites
Metals, 2019
In this study, high volume fraction B4C reinforced Al matrix composites were fabricated with a liquid pressing process. Microstructural analysis by scanning electron microscope and a transmission electron microscopy shows a uniform distribution of the B4C reinforcement in the matrix, without any defects such as pore and unwanted reaction products. The compressive strength and wear properties of the Al7075 matrix and the composite were compared at room temperature, 100, 200, and 300 °C, respectively. The B4C reinforced composite showed a very high ultimate compression strength (UCS) over 1.4 GPa at room temperature. The UCS gradually decreased as the temperature was increased, and the UCS of the composite at 300 °C was about one third of the UCS of the composite at room temperature. The fractography of the compressive test specimen revealed that the fracture mechanism of the composites was the brittle fracture mode at room temperature during the compression test. However, at the elev...
Al/B 4 C Composites with 5 And 10 wt% Reinforcement Content Prepared By Powder Metallurgy
The preparation, physical and mechanical properties of Al/B 4 C composites with 5 and 10 wt.% reinforcement content were investigated. In order to obtain the feedstock with a low powder loading, B 4 C mixtures containing fine powders were investigated to obtain the optimal particle packing. The experimental results indicated that the fine containing 5 and 10 wt.% particles are able to prepare the feedstock with a good flowability. The composites fabricated by powder metallurgy have low densities and homogeneous microstructures. Additionally there is no interface reaction observed between the reinforcement and matrix by XRD analysis. The hardness of Al/B 4 C composites prepared by powder metallurgy was high. ABSTRAK Persediaan, sifat-sifat mekanikal dan fizikal Al/komposit B 4 C dengan 5 dan 10 % berat peneguhan kandungan telah disiasat. Supaya mendapatkan stok suapan dengan pemuatan serbuk rendah, campuran-campuran B 4 C mengandungi serbuk halus disiasat memperoleh padatan zarah opt...