Fabrication and Mechanical Properties of Alumina—CNTs Composites

2011 ◽  
Vol 66-68 ◽  
pp. 1390-1396
Author(s):  
Jing Song Zhao ◽  
Yi Feng ◽  
Nan Nan Chen ◽  
Fan Yan Chen ◽  
Jie Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Powder Metallurgy ◽  
Nuclear Waste ◽  
Mass Fraction ◽  
Bending Strength ◽  
Waste Material ◽  
Powder Metallurgy Method ◽  
The Matrix

The transmutation target of nuclear waste material has been fabrication by a powder metallurgy method by using Alumina as the matrix and CNTs as reinforcement. The effect of different nanotube contents on the fracture toughness and the bending strength was investigation. The results showed the fracture toughness and the bending strength of composites increased with increasing CNTs mass fraction when the content of CNTs was less than 1.5%. However, when the contents of CNTs greater than 1.5%, the fracture toughness and the bending strength of composites decreased as the content of CNTs increased. Possible mechanisms are discussed in detail in the paper.

scholarly journals Effect of Lubricating Phase on Microstructure and Properties of Cu–Fe Friction Materials

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 313 ◽  
Author(s):  
Xiaoyang Wang ◽  
Hongqiang Ru
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Carbon Black ◽  
Tribological Properties ◽  
Mass Fraction ◽  
Bending Strength ◽  
High Strength ◽  
Wear Loss ◽  
Powder Metallurgy Method ◽  
Friction Materials

Cu–Fe-based friction materials with flake graphite, granulated carbon black, and high-strength graphite as lubricating phase were prepared by the powder metallurgy method. The effects of different types and mass fraction of lubricating phase on the microstructure, mechanical properties, and tribological properties were investigated. The results show that when the mass fraction of granulated carbon black is 5 wt%, it is easy to form a good interface with the matrix, but the interface is prone to pores and cracks when its mass fraction is 10 wt%. The bending strength and compressive strength properties of the composites increased with increasing in the mass fraction of granulated carbon black and reached the maximum of 40 MPa and 70 MPa at 5 wt% granulated carbon black, after which bending strength and compressive strength all decreased. The friction coefficient and the wear loss of the materials initially decreased as the mass fraction of granulated carbon black increased and obtained minimum of 0.436 and 0.145 mm when the mass fraction of granulated carbon black was 5 wt%, then ascended. Compared with the sample with 5 wt% high-strength graphite as lubricating phase, the sample with 5 wt% granulated carbon black as lubricating phase had better sintering performance, mechanical properties, and tribological properties.

Mechanical Properties and Microstructure of PMMA-ZrO2 Nanocomposites for Dental CAD/CAM

2013 ◽  
Vol 785-786 ◽  
pp. 533-536 ◽  
Author(s):  
Shi Bao Li ◽  
Yi Min Zhao ◽  
Jian Feng Zhang ◽  
Cheng Xie ◽  
Dong Mei Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
In Situ Polymerization ◽  
Zirconia Ceramics ◽  
Sem Images ◽  
The Matrix ◽  
Cad Cam ◽  
Organic Resin

A novel PMMA-ZrO2 composite (PZC) was prepared by resin infiltrated to ceramic method. The composite mechanical properties were evaluated and correlated to its microstructure. Partially sintered zirconia ceramics (PSZC) were made by isostatic pressing and partially sintering. Subsequently, the PZC was prepared by vacuum infiltrating prepolymerized MMA into PSZC, followed by in-situ polymerization. When PSZC-70% was used as the matrix, the bending strength, elastic modulus, and fracture toughness of the prepared composite i.e PZC-70% were 202.56±12.09 MPa, 58.71±3.98 GPa, and 4.60±0.26 MPa·m1/2, corresponding to 25.69%, 23.31%, and 169.01% improvement, respectively, in comparison with the control matrix. Among them, the fracture toughness improvement was the most prominent. According to SEM images of the fracture surfaces, each pore of zirconia skeleton was filled by organic resin contributing to the bending strength improvement. These weak interfaces between zirconia skeleton and organic resin absorbed energy and terminated the growth of microcracks which might be responsible for significant improvement in fracture toughness. This PZC material is anticipated to be a new member of the dental CAD/CAM family.

Preparation and Properties of Cf-TiB2-Cu-Graphite Composites

2012 ◽  
Vol 535-537 ◽  
pp. 8-13
Author(s):  
Shao Fan Xu ◽  
Shao Ping Xu ◽  
Cheng Nan Zhu ◽  
Chuan Yong Yuan
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Powder Metallurgy ◽  
Dry Friction ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Powder Metallurgy Method ◽  
Sliding Velocity ◽  
Graphite Composite ◽  
Graphite Composites

Copper-plated TiB2-Cu-graphite composite, Cf-TiB2-Cu-graphite composite and Cf-copper-plated TiB2-Cu-graphite composite with the same TiB2 content were prepared by the powder metallurgy method. Physical and mechanical properties of these composites were tested. The dry friction tests of the composites under sliding velocity of 10m/s and load of 4.9N were conducted for 36h. The results show that the properties of the Cf-copper-plated TiB2-Cu-graphite composite such as electric conductivity, hardness, bending strength and wear resistance are increased remarkably than those of either Cf-TiB2-Cu-graphite or copper-plated TiB2-Cu-graphite composites.

Meso-Structure Design of B4C-Al/Al Composites by Hot Pressing

2016 ◽  
Vol 849 ◽  
pp. 801-806
Author(s):  
Hui Li ◽  
Yi Tan Zhang ◽  
Kei Ameyama ◽  
Hai Jun Yang ◽  
Zhi Guo Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Electron Microscope ◽  
Powder Metallurgy ◽  
Scanning Electron Microscope ◽  
Deformation Mechanism ◽  
Mass Fraction ◽  
Structure Design ◽  
Powder Metallurgy Method ◽  
Scanning Electron

According to the theory of meso-structure design, milling powders were blended with un-milled Al particulate to increase ductility. Two kinds of Al particulate-toughened composites were fabricated by using powder metallurgy method, where the mass fraction of B4C in the B4C-Al agglomerate particles was 40%, but 32% and 16% in the whole composite. The microstructure of composites was examined by scanning electron microscope (SEM), and its mechanical properties were studied. The results indicate that Al particulate-toughened sample has a slight plasticity with bulks of aluminum alloy in the composite. But meso-structure design has no effect on improvement on the plasticity and toughness of the sample B4C-Al/Al (16%)(3#), where the mass fraction of B4C in the whole composite is 16%. In the present study, the strengthening and deformation mechanism of the composites were also discussed.

Sintered High Carbon Steels: Effect of Thermomechanical Treatments on their Mechanical and Wear Performance

2008 ◽  
Vol 591-593 ◽  
pp. 271-276 ◽  
Author(s):  
M.A. Martinez ◽  
R. Calabrés ◽  
J. Abenojar ◽  
Francisco Velasco
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Powder Metallurgy ◽  
Thermomechanical Treatment ◽  
Bending Strength ◽  
Carbon Steels ◽  
Tool Steels ◽  
High Carbon ◽  
Wear Performance ◽  
Metallographic Study

In this work, ultrahigh carbon steels (UHCS) obtained by powder metallurgy with CIP and argon sintered at 1150°C. Then, they were rolled at 850 °C with a reduction of 40 %. Finally, steels were quenched at 850 and 1000 °C in oil. In each step, hardness, bending strength and wear performance were evaluated. Obtained results are justified with a metallographic study by SEM. Both mechanical properties and wear resistance are highly favoured with the thermomechanical treatment that removes the porosity of the material. Moreover, final quenching highly hardens the material. The obtained material could be used as matrix for tool steels.

In Situ Preparation and Mechanical Properties of (ZrB2+ZrC)/Zr3[Al(Si)]4C6 Composites

2014 ◽  
Vol 602-603 ◽  
pp. 438-442
Author(s):  
Lei Yu ◽  
Jian Yang ◽  
Tai Qiu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Raw Materials ◽  
Linear Increase ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Uniform Microstructure

Fully dense (ZrB2+ZrC)/Zr3[Al (Si)]4C6 composites with ZrB2 content varying from 0 to 15 vol.% and fixed ZrC content of 10 vol.% were successfully prepared by in situ hot-pressing in Ar atmosphere using ZrH2, Al, Si, C and B4C as raw materials. With the increase of ZrB2 content, both the bending strength and fracture toughness of the composites increase and then decrease. The synergistic action of ZrB2 and ZrC as reinforcements shows significant strengthening and toughing effect to the Zr3[Al (Si)]4C6 matrix. The composite with 10 vol.% ZrB2 shows the optimal mechanical properties: 516 MPa for bending strength and 6.52 MPa·m1/2 for fracture toughness. With the increase of ZrB2 content, the Vickers hardness of the composites shows a near-linear increase from 15.3 GPa to 16.7 GPa. The strengthening and toughening effect can be ascribed to the unique mechanical properties of ZrB2 and ZrC reinforcements, the differences in coefficient of thermal expansion and modulus between them and Zr3[Al (Si)]4C6 matrix, fine grain strengthening and uniform microstructure derived by the in situ synthesis reaction.

Effects of TiN Content on Mechanical Properties and Microstructure of ATN Materials

2013 ◽  
Vol 589-590 ◽  
pp. 590-593 ◽  
Author(s):  
Min Wang ◽  
Jun Zhao
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Fracture Toughness ◽  
Vickers Hardness ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Ceramic Materials ◽  
Hot Press ◽  
Hot Press Sintering ◽  
Tin Content

In order to investigate the effects of TiN content on Al2O3/TiN ceramic material (ATN), the ATN ceramic materials were prepared of TiN content in 30%, 40%, 50%, 60% in the condition of hot press sintering. The sintering temperature is 1700°C, the sintering press is 32MPa, and the holding time are 5min, 10min, 15min. The effects of TiN content on mechanical properties and microstructure of ATN ceramic materials were investigated by analyzing the bending strength, hardness, fracture toughness. The results show that ATN50 has the best mechanical property, its bending strength is 659.41MPa, vickers hardness is 13.79GPa, fracture toughness is 7.06MPa·m1/2. It is indicated that the TiN content has important effect on microstructure and mechanical properties of ATN ceramic materials.

Preparation and Properties of SiC/Phenolic Resin for the Heat of LED

2016 ◽  
Vol 848 ◽  
pp. 454-459
Author(s):  
Cong Wu ◽  
Kang Zhao ◽  
Yu Fei Tang ◽  
Ji Yuan Ma
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Powder Metallurgy ◽  
Phenolic Resin ◽  
Bending Strength ◽  
Experimental Results ◽  
Low Thermal Conductivity ◽  
Industry Standard ◽  
Insulation Performance

In order to solve the problem that low thermal conductivity of the plastics for the heat of LED, SiC/Phenolic resin for the heat of LED were fabricated combining powder metallurgy. The effects of particles diameters, content and adding nanoparticles on thermal conductivity of the fabricated composites were investigated, the mechanical properties were also characterized. The experimental results showed that the materials were obtained, and the insulation performance of the fabricated SiC/Phenolic resin was higher than the industry standard one, the thermal conductivity reached 4.1W/(m·k)-1. And the bending strength of the fabricated composites was up to 68.11MPa. The problem of low thermal conductivity of the material is expected to be solved. In addition, it is meaningful for improving LED life.

Fabrication of Carbon Nanotube Reinforced Boron Carbide Composite by Hot-Pressing Following Extrusion Molding

2014 ◽  
Vol 616 ◽  
pp. 27-31 ◽  
Author(s):  
Tomohiro Kobayashi ◽  
Katsumi Yoshida ◽  
Toyohiko Yano
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Boron Carbide ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Bending Strength ◽  
Extrusion Direction ◽  
Sem Observation

The CNT/B4C composite with Al2O3 additive was fabricated by hot-pressing following extrusion molding of a CNT/B4C paste, and mechanical properties of the obtained composite were investigated. Many CNTs in the composite aligned along the extrusion direction from SEM observation. 3-points bending strength of the composite was slightly lower than that of the monolithic B4C. Elastic modulus and Vickers hardness of the composite drastically decreased with CNT addition. Fracture toughness of the composite was higher than that of the monolithic B4C.

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