Mechanical properties and strengthening mechanism of the hydrothermal synthesis of nano-sized α-Al2O3 ceramic particle reinforced molybdenum alloy

Al2O3/TiAl in situ composites doped with Cr and V2O5 were successfully prepared from Ti, Al, TiO2, Cr and V2O5 by hot pressing. The effect of in situ formed Al2O3 content on the phase composition, microstructure and mechanical properties of Al2O3/TiAl composites were investigated. The results show that the as-synthesized composites mainly consisted of ?-TiAl/?2-Ti3Al matrix and dispersive Al2O3 reinforcing phases. The in situ formed fine Al2O3 ceramic particles mainly disperse on the grain boundaries of TiAl, resulting in refinement of TiAl matrix, which improves the mechanical properties of the Al2O3/TiAl in situ composite. The composite with 7.54 at.% Al2O3 possesses the maximum flexural strength and fracture toughness of 335.38 MPa and 5.39 MPa m1/2, respectively. The strengthening mechanism was also discussed in detail.

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Insight into the strengthening mechanism of α-Al2O3/γ-Fe ceramic-metal interface doped with Cr, Ni, Mg, and Ti

Ceramics International ◽

10.1016/j.ceramint.2021.05.001 ◽

2021 ◽

Author(s):

Renwei Li ◽

Qicheng Chen ◽

Liang Ouyang ◽

Yingjin Zhang ◽

Binjian Nie ◽

...

Keyword(s):

Strengthening Mechanism ◽

Metal Interface ◽

Α Al2o3 ◽

Insight Into

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Synergistic strengthening mechanism of copper matrix composite reinforced with nano-Al2O3 particles and micro-SiC whiskers

Nanotechnology Reviews ◽

10.1515/ntrev-2021-0006 ◽

2021 ◽

Vol 10 (1) ◽

pp. 62-72

Author(s):

Huanran Lin ◽

Xiuhua Guo ◽

Kexing Song ◽

Jiang Feng ◽

Shaolin Li ◽

...

Keyword(s):

Mechanical Properties ◽

Erosion Resistance ◽

Strengthening Mechanism ◽

Copper Matrix ◽

Heavy Duty ◽

Arc Erosion ◽

Comprehensive Performance ◽

Sic Whiskers ◽

Copper Matrix Composite ◽

Time And Energy

Abstract Although Cu–Al2O3 composites have good comprehensive performance, higher mechanical properties and arc erosion resistance are still required to meet heavy-duty applications such as electromagnetic railguns. In this work, a novel hybrid SiCw/Cu–Al2O3 composite was successfully prepared by combining powder metallurgy and internal oxidation. The microstructure and mechanical behavior of the SiCw/Cu–Al2O3 composite were studied. The results show that nano-Al2O3 particles and micro-SiCw are introduced into the copper matrix simultaneously. Well-bonded interfaces between copper matrix and Al2O3 particles or SiCw are obtained with improved mechanical and arc erosion resistance of SiCw/Cu–Al2O3 composite. The ultimate tensile strength of the SiCw/Cu–Al2O3 composite is 508.9 MPa, which is 7.9 and 56.1% higher than that of the Cu–Al2O3 composite and SiCw/Cu composite, respectively. The strengthening mechanism calculation shows that Orowan strengthening is the main strengthening mechanism of the SiCw/Cu–Al2O3 composite. Compared with Cu–Al2O3 composite, the hybrid SiCw/Cu–Al2O3 composite has lower arc time and energy and better arc stability.

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Assessing the Flexural Properties of Epoxy Composites with Extremely Low Addition of Cellulose Nanofiber Content

Applied Sciences ◽

10.3390/app10031159 ◽

2020 ◽

Vol 10 (3) ◽

pp. 1159 ◽

Cited By ~ 3

Author(s):

Yingmei Xie ◽

Hiroki Kurita ◽

Ryugo Ishigami ◽

Fumio Narita

Keyword(s):

Mechanical Properties ◽

Epoxy Resin ◽

Flexural Modulus ◽

Strengthening Mechanism ◽

Short Fiber ◽

Cellulose Nanofiber ◽

Resin Matrix ◽

Element Analysis ◽

Epoxy Resin Matrix ◽

The Matrix

Epoxy resins are a widely used common polymer due to their excellent mechanical properties. On the other hand, cellulose nanofiber (CNF) is one of the new generation of fibers, and recent test results show that CNF reinforced polymers have high mechanical properties. It has also been reported that an extremely low CNF addition increases the mechanical properties of the matrix resin. In this study, we prepared extremely-low CNF (~1 wt.%) reinforced epoxy resin matrix (epoxy-CNF) composites, and tried to understand the strengthening mechanism of the epoxy-CNF composite through the three-point flexural test, finite element analysis (FEA), and discussion based on organic chemistry. The flexural modulus and strength were significantly increased by the extremely low CNF addition (less than 0.2 wt.%), although the theories for short-fiber-reinforced composites cannot explain the strengthening mechanism of the epoxy-CNF composite. Hence, we propose the possibility that CNF behaves as an auxiliary agent to enhance the structure of the epoxy molecule, and not as a reinforcing fiber in the epoxy resin matrix.

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Effects of Sr Addition on Mechanical Properties and Microstructure of Mg-6Al Magnesium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.686.120 ◽

2011 ◽

Vol 686 ◽

pp. 120-124

Author(s):

Jin Ping Fan ◽

She Bin Wang ◽

Bing She Xu

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Magnesium Alloy ◽

Strengthening Mechanism ◽

Microstructure And Mechanical Properties ◽

Higher Temperature ◽

Lower Temperature

The effects of Sr addition on the mechanical properties and microstructure of Mg-6Al mag- nesium alloy both at 25 °C and at 175 °C were investigated by means of OM, SEM and EDS and XRD. Upon the Sr addition of 2%, the tensile strength was increased by 7.2% to 184.4MPa at 25 °C, while it was increased by 30% to 155.4MPa at 175 °C. The strengthening mechanism of Mg-6Al-xSr at lower temperature (25 °C) was different from that at higher temperature (175°C). The results show that the addition of strontium effectively improved the microstructure and mechanical properties of magnesium alloy.

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Microstructure and Strengthening Mechanism of Oxide Lanthanum Dispersion Strengthened Molybdenum Alloy

Advanced Engineering Materials ◽

10.1002/adem.200400072 ◽

2004 ◽

Vol 6 (12) ◽

pp. 943-948 ◽

Cited By ~ 30

Author(s):

G.-J. Zhang ◽

Y.-J. Sun ◽

R.-M. Niu ◽

J. Sun ◽

J.-F. Wei ◽

...

Keyword(s):

Strengthening Mechanism ◽

Molybdenum Alloy

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Sintering Behavior and Mechanical Properties of Mullite Fibers/Hydroxyapatite Ceramic

Materials ◽

10.3390/ma11101859 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1859 ◽

Cited By ~ 3

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.

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