scholarly journals High Temperature Mechanical Properties and Wear Performance of B4C/Al7075 Metal Matrix Composites

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1108 ◽  
Author(s):  
Sangmin Shin ◽  
Donghyun Lee ◽  
Yeong-Hwan Lee ◽  
Seongmin Ko ◽  
Hyeonjae Park ◽  
...  
Keyword(s):  
High Temperature ◽  
Fracture Mechanism ◽  
Room Temperature ◽  
Volume Fraction ◽  
Microstructural Analysis ◽  
Wear Loss ◽  
Matrix Composites ◽  
Pressing Process ◽  
Liquid Pressing Process ◽  
Al Matrix

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 elevated temperature, AMCs had a mixed mode of a brittle and ductile fracture mechanism under the compressive load. The composite produced by a liquid pressing process also showed superior wear resistance compared with the Al matrix. The result of the wear test indicates that the wear loss of the Al matrix at 300 °C was two times higher than that of the AMCs, which is attributed to the formation of a mechanically mixed layer (MML) in the composites at the high temperature.

scholarly journals Fabrication of TiB2–Al1050 Composites with Improved Microstructural and Mechanical Properties by a Liquid Pressing Infiltration Process

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1588
Author(s):  
Seongmin Ko ◽  
Hyeonjae Park ◽  
Yeong-Hwan Lee ◽  
Sangmin Shin ◽  
Ilguk Jo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Metal Matrix ◽  
Load Transfer ◽  
Volume Fraction ◽  
High Volume ◽  
Matrix Composites ◽  
Infiltration Process ◽  
Al Composite ◽  
Al Matrix

This study was conducted on titanium diboride (TiB2) reinforced Al metal matrix composites (MMCs) with improved properties using a TiB2 and aluminum (Al) 1050 alloy. Al composites reinforced with fine TiB2 at volume ratios of more than 60% were successfully fabricated via the liquid pressing infiltration (LPI) process, which can be used to apply gas pressure at a high temperature. The microstructure of the TiB2–Al composite fabricated at 1000 °C with pressurization of 10 bar for 1 h showed that molten Al effectively infiltrated into the high volume-fraction TiB2 preform due to the improved wettability and external gas pressurization. In addition, the interface of TiB2 and Al not only had no cracks or pores but also had no brittle intermetallic compounds. In conclusion, TiB2–Al composite, which has a sound microstructure without defects, has improved mechanical properties, such as hardness and strength, due to effective load transfer from the Al matrix to the fine TiB2 reinforcement.

Effect of Volume Fraction of Reinforcement on the Microstructure and Mechanical Properties of In Situ (TiB+TiC)/Ti Composite

2011 ◽  
Vol 335-336 ◽  
pp. 137-141 ◽  
Author(s):  
Yuong Chen ◽  
Chang Jiang Zhang ◽  
Fan Tao Kong ◽  
Hong Zhi Niu ◽  
Fang Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Room Temperature ◽  
Volume Fraction ◽  
Microstructural Analysis ◽  
Matrix Composites ◽  
Alloy Matrix

In the present study, Ti-6Al-2.5Sn-4Zr-0.7Mo-0.3Si-0.3Y alloy matrix composites reinforced with TiB and TiC were fabricated by combustion-assisted cast utilizing the reaction between titanium and B4C, graphite. The microstructure, room temperature mechanical properties were presented and discussed. Microstructural analysis of the composites revealed that the prior β grain size as well as the thickness of α colony significantly refined with increasing of volume fraction. At room temperature (RT), tensile strength and elastic modulus increase significantly, while the ductility drops gradually possibly because of the cracking of TiB whiskers and TiC particles.

scholarly journals Enhancement on the Tribological Properties of the Multilayer RGO/Al Matrix Composites by Cu-Coating Method

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3163
Author(s):  
Fengguo Liu ◽  
Ning Su ◽  
Renguo Guan
Keyword(s):  
Electron Microscope ◽  
Tribological Properties ◽  
Milled Powder ◽  
Wear Loss ◽  
Matrix Composites ◽  
Tem Analysis ◽  
Lubricating Film ◽  
Coating Method ◽  
Al Matrix Composites ◽  
Al Matrix

Multilayer reduced graphene oxide (mrGO) was chemically modified by electroless plating of copper on surface to form mrGO-Cu. The scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis revealed that nano-Cu particles were uniformly dispersed on the surface of mrGO. The mrGO-Cu powders were further utilized as reinforcements for aluminum (Al) matrix and the mrGO-Cu/Al composite was successfully fabricated through clad rolling of milled powder. The tribological properties of the mrGO-Cu/Al composites were explored. The tribological results show that the mrGO-Cu could reduce the friction coefficient and wear loss of mrGO-Cu/Al composites, since the mrGO-Cu participated in lubricating processes due to the formation of a transfer layer on the contact surface. Furthermore, it is found that the composition of mrGO-Cu could significantly influence the tribological properties of the mrGO-Cu/Al composites. The composites with 4% of mrGO-Cu for composites exhibited the best tribological behavior, which transformed from adhesive wear to abrasive wear, due to the formation of a graphite lubricating film.

Thermo-Physical Properties of Copper Matrix Composites Reinforced with 3D-SiC Network

2010 ◽  
Vol 150-151 ◽  
pp. 144-149
Author(s):  
Hong Wei Xing ◽  
Jin Song Zhang ◽  
Xiao Ming Cao
Keyword(s):  
Thermal Conductivity ◽  
Physical Properties ◽  
Room Temperature ◽  
Volume Fraction ◽  
Copper Matrix ◽  
High Thermal Stability ◽  
Matrix Composites ◽  
Copper Matrix Composites ◽  
Specific Heat Capacities ◽  
Thermo Physical Properties

Copper matrix composites reinforced with 3D-SiC network (15v% and 20v% SiC) were fabricated by squeezing copper alloy into 3D-SiC network preforms. The thermo-physical properties of the copper matrix composites were investigated. The specific heat capacities of the composites were about 0.39~0.50 J•g-1•K-1. The coefficients of thermal expansion (CTEs) of the composites were found to be lower than 6.9×10-6 -1 at Room Temperature. The composites exhibited high thermal stability for 3D-SiC network advent. The thermal conductivity of the composites was in the range of 50~80W•m−1•K−1. The thermo-physical properties of Cu matrix composites had a great relationship with the structures of 3D-SiC network preforms. The thermal conductivity of the composites decreased with an increase in the volume fraction of SiC or the structures of the limbs changing compacted, but the CTEs were not completely according this rule.

scholarly journals Microstructure and Tensile Properties of Graphene-Oxide-Reinforced High-Temperature Titanium-Alloy-Matrix Composites

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3358 ◽  
Author(s):  
Hang Chen ◽  
Guangbao Mi ◽  
Peijie Li ◽  
Xu Huang ◽  
Chunxiao Cao
Keyword(s):  
Tensile Strength ◽  
Titanium Alloy ◽  
Graphene Oxide ◽  
High Temperature ◽  
Yield Strength ◽  
Room Temperature ◽  
Second Phase ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
The Matrix

In this study, graphene-oxide (GO)-reinforced Ti–Al–Sn–Zr–Mo–Nb–Si high-temperature titanium-alloy-matrix composites were fabricated by powder metallurgy. The mixed powders with well-dispersed GO sheets were obtained by temperature-controlled solution mixing, in which GO sheets adsorb on the surface of titanium alloy particles. Vacuum deoxygenating was applied to remove the oxygen-containing groups in GO, in order to reduce the introduction of oxygen. The compact composites with refined equiaxed and lamellar α phase structures were prepared by hot isostatic pressing (HIP). The results show that in-situ TiC layers form on the surface of GO and GO promotes the precipitation of hexagonal (TiZr)6Si3 particles. The composites exhibit significant improvement in strength and microhardness. The room-temperature tensile strength, yield strength and microhardness of the composite added with 0.3 wt% GO are 9%, 15% and 27% higher than the matrix titanium alloy without GO, respectively, and the tensile strength and yield strength at 600 °C are 3% and 21% higher than the matrix alloy. The quantitative analysis indicates that the main strengthening mechanisms are load transfer strengthening, grain refinement and (TiZr)6Si3 second phase strengthening, which accounted for 48%, 30% and 16% of the improvement of room-temperature yield strength, respectively.

scholarly journals Study on Wear and Fatigue Performance of Two Types of High-Speed Railway Wheel Materials at Different Ambient Temperatures

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1152
Author(s):  
Lei MA ◽  
Wenjian WANG ◽  
Jun GUO ◽  
Qiyue LIU
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
High Speed ◽  
Room Temperature ◽  
Lamellar Spacing ◽  
Wear Loss ◽  
High Speed Railway ◽  
Railway Wheel ◽  
Ambient Temperatures ◽  
Railway Wheels

The wear and fatigue behaviors of two newly developed types of high-speed railway wheel materials (named D1 and D2) were studied using the WR-1 wheel/rail rolling–sliding wear simulation device at high temperature (50 °C), room temperature (20 °C), and low temperature (−30 °C). The results showed that wear loss, surface hardening, and fatigue damage of the wheel and rail materials at high temperature (50 °C) and low temperature (−30 °C) were greater than at room temperature, showing the highest values at low temperature. With high Si and V content refining the pearlite lamellar spacing, D2 presented better resistance to wear and fatigue than D1. Generally, D2 wheel material appears more suitable for high-speed railway wheels.

Matrix Microstructural Analysis

2010 ◽  
pp. 211-222
Keyword(s):  
High Temperature ◽  
Natural Fiber ◽  
Fiber Composite ◽  
Microstructural Analysis ◽  
Fiber Reinforced Composites ◽  
Matrix Composites ◽  
Thermoplastic Matrix ◽  
Carbon Fiber Reinforced Composites ◽  
Natural Fiber Composite

Abstract Microstructural analysis of the composite matrix is necessary to understand the performance of the part and its long-term durability. This chapter focuses on the microstructural analysis of engineering thermoplastic-matrix composites and the influence of cooling rate and nucleation on the formation of spherulites in high-temperature thermoplastic-matrix carbon-fiber-reinforced composites. It also describes the microstructural analysis of a bio-based thermosetting-matrix natural fiber composite system.

scholarly journals Study of the Microstructure and Ring Element Segregation Zone of Spray Deposited SiCp/7055Al

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1299 ◽  
Author(s):  
Hao Yang ◽  
Xin-wei She ◽  
Bin-bin Tang ◽  
Chun-mei Li ◽  
Xian-quan Jiang
Keyword(s):  
Volume Fraction ◽  
Spray Deposition ◽  
Optical Microscope ◽  
Matrix Composites ◽  
Pinning Effect ◽  
Sic Particles ◽  
Transmission Electron ◽  
Al Matrix Composites ◽  
Element Enrichment ◽  
Al Matrix

Composites of 7055 aluminum (Al) matrix reinforced with SiC particles were prepared using the spray deposition method. The volume fraction of the phase reinforced with SiC particles was 17%. The effect of the introduction of SiC particles on the deposited microstructure and properties of the composites was studied in order to facilitate the follow-up study. The structure and element enrichment zone of spray-deposited SiCp/7055 Al matrix composites were studied by Optical Microscope (OM), X-ray diffraction (XRD), Scanning Electronic Microscopy (SEM) and Transmission electron microscopy (TEM). The results show that the reinforcement phases of the SiC particles were uniformly distributed on the macro and micro levels, and a few SiC particles were segregated into annular closed regions. C and Si on the surface of SiC particles diffused to the Al matrix. The distribution of the two elements was gradient weakening with SiC particles as the center, and the enrichment zones of Si, Mg and Cu formed in the middle of the closed annular area of a few SiC particles. The enrichment zones were mainly composed of alpha-Al, SiC, Al2CuMg, Al2Cu and MgZn2. AlCu and AlMgCu phase precipitate on the surface of the SiC particles, beside the particle boundary, and had the characteristics of preferred nucleation. They tended to grow at the edges and corners of SiC particles. It was observed that the formation of nanoparticles in the alloy had a pinning effect on dislocations. The different cooling rates of the SiC particles and the Al matrix led to different aluminum liquid particle sizes, ranging from 20 to 150 μm. In the region surrounded by SiC particles, the phenomenon of large particles extruding small particles was widespread. Tearing edges and cracks continued to propagate around the SiC particles, increasing their propagation journey and delaying the fracture of the materials.

Nanoscale Alumina-Reinforced Aluminum Matrix Composites: Microstructure and Mechanical Properties

2008 ◽  
Vol 395 ◽  
pp. 157-178
Author(s):  
Ji Xiong Han ◽  
Yong Ching Chen ◽  
Vijay K. Vasudevan
Keyword(s):  
Room Temperature ◽  
Void Formation ◽  
Aluminum Matrix ◽  
High Hardness ◽  
Heat Treating ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Recovery Processes ◽  
To Come ◽  
Al Matrix

Studies were carried out on microstructure evolution and mechanical behavior of an Al matrix–nanoscale Al2O3 particulate-reinforced composite. The thermal stability of the composite, evaluated by heat treating specimens at temperatures from 300 to 600 °C for times varying from 1 to 100 hours, revealed that the nano-sized (30-100 nm) Al2O3 particles present in the as-received/ascast material coalesced into larger particles, but with sizes still in the 100 to 500 nm range. Despite the coarsening of the particles, high hardness was retained. The tensile properties of both the as-cast DSC material and those thermally soaked for 500 hours at a number of temperatures were evaluated. The results showed that the yield strength was quite high (283 MPa) at room temperature and decreased nearly linearly with temperature, though values as high as 110 MPa were obtained at 400oC. Thermal soaking did not have a detrimental effect on strength. Although the macroscopic ductility of both unsoaked and soaked materials remained quite low over the entire temperature range, SEM observations of the fracture surfaces provided substantial evidence for high localized plasticity as manifested by stretching, tearing and void formation in the Al matrix around the oxide particles. Possible strengthening mechanisms, including grain size reduction, Orowan bypass and forest hardening, were considered and modeled. Good agreement between the calculated and experimental strengths was obtained, and majority of the strengthening at room temperature was found to come from forest hardening (i.e, increase in dislocation density caused by the thermal expansion mismatch between Al and Al2O3), with secondary contributions from the Orowan mechanism. TEM observations provided confirmatory evidence for these mechanisms. The decrease in strength at higher temperatures was attributed to a diminishing contribution from forest hardening due to recovery processes.

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