scholarly journals Influence of the Dopants on the Mechanical Properties of Alumina-Based Ceramics

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Anton Sergeevich Kaygorodov ◽  
Vasily Ivanovich Krutikov ◽  
Sergey Nikolaevich Paranin
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Wear Resistance ◽  
Elastic Modulus ◽  
Hot Pressing ◽  
Synthesis Method ◽  
Crystalline Lattice ◽  
Alumina Matrix ◽  
Pure Alumina ◽  
Sufficient Decrease

In the present study the mechanical properties of dense alumina-based ceramics obtained by two processing routes are investigated. The application of magnetic-pulsed compaction or hot pressing of the powder leads to a comparable combination of microhardness, elastic modulus, and fracture toughness. The insertion of Al into Al2O3 powder increases the microdistortions of the crystalline lattice, resulting in the sufficient decrease of indentation wear-resistance. The usage of ZrO2 or TiCN as dopants to alumina matrix improves slightly the mechanics of the composites with a noticeable decrease of the material lost by 30% compared to pure alumina at closely spaced arrays of indents. Regardless of the synthesis method, the ceramic grains were formed completely with the fracture travelling along the grain boundaries.

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.

Microstructural and Mechanical Properties of Ti3SiC2 Composites

2008 ◽  
Vol 403 ◽  
pp. 189-192
Author(s):  
Jow Lay Huang ◽  
Horng Hwa Lu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Wear Resistance ◽  
Chemical Stability ◽  
Hot Pressing ◽  
Ceramic Composites ◽  
Fracture Mechanisms ◽  
Jet Engines ◽  
Potential Applications ◽  
New Material

Ti3SiC2 has been a spectacular material, as it combines many of the best properties of metals and ceramics. This new material has potential applications for fabrication of jet engines and in bonding phases. Microstructure can further enhance the mechanical properties, such as strength, wear resistance and chemical stability. In the current research the different starting powder systems were used to synthesize Ti3SiC2 by hot pressing. The contents of Si were controlled appropriately to obtain Ti3SiC2/TiC ceramic composites. Preliminary results indicated that the fracture toughness and strength were improved. The influences of TiC contents on the microstructure and mechanical properties were investigated and the fracture mechanisms of Ti3SiC2/TiC ceramic composites are discussed qualitatively.

scholarly journals Fabrication of Ti3AlC2/Al2O3 nanocomposite by a novel method

2011 ◽  
Vol 43 (3) ◽  
pp. 289-294 ◽  
Author(s):  
J. Zhu ◽  
L. Ye ◽  
F. Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Hot Pressing ◽  
Reaction Path ◽  
Raw Materials ◽  
High Energy ◽  
Good Combination ◽  
High Energy Milling ◽  
Al2o3 Composite ◽  
Novel Method

A Ti3AlC2/Al2O3 nanocomposite was synthesized using Ti, Al, C and TiO2 as raw materials by a novel combination of high-energy milling and hot pressing. The reaction path of the 3Ti-8C-16Al-9TiO2 mixture of powders was investigated, and the results show that the transitional phases TiC, TixAly and Al2O3 are formed in high-energy milling first, and then TixAly is transformed to the TiAl phase during the hot pressing. Finally, a reaction between TiC and TiAl occurs to produce Ti3AlC2 and the nanosized Ti3AlC2/Al2O3 composite is synthesized. The Ti3AlC2/Al2O3 composite possessed a good combination of mechanical properties with a hardness of 6.0 GPa, a flexural strength of 600 MPa, and a fracture toughness (K1C) of 5.8 MPa?m1/2. The strengthening and toughening mechanisms were also discussed.

scholarly journals Microstructural and Mechanical Properties of β-Type Ti–Nb–Sn Biomedical Alloys with Low Elastic Modulus

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 712 ◽  
Author(s):  
Peiyou Li ◽  
Xindi Ma ◽  
Duo Wang ◽  
Hui Zhang
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Elastic Modulus ◽  
Martensite Phase ◽  
Ti Alloy ◽  
Martensitic Phase Transition ◽  
Low Elastic Modulus ◽  
Nb Content ◽  
Biomedical Alloy ◽  
Cp Ti

The microstructural and mechanical properties of β-type Ti85-xNb10+xSn5 (x = 0, 3, 6, 10 at.%) alloys with low elastic modulus were investigated. The experimental results show that the Ti85Nb10Sn5 and Ti75Nb20Sn5 alloys are composed of simple α and β phases, respectively; the Ti82Nb13Sn5 and Ti79Nb16Sn5 alloys are composed of β and α″ phases. The content of martensite phase decreases with the increase of Nb content. The Ti82Nb13Sn5 and Ti79Nb16Sn5 alloys show an inverse martensitic phase transition during heating. The Ti85Nb10Sn5 and Ti82Nb13Sn5 alloys with the small residual strain exhibit the good superelastic properties in 10-time cyclic loading. The reduced elastic modulus (Er) of the Ti75Nb20Sn5 alloy (61 GPa) measured by using the nanoindentation technique is 2–6 times of that of human bone (10–30 GPa), and is smaller than that of commercial Ti-6Al-4V biomedical alloy (120 GPa). The Ti75Nb20Sn5 alloy can be considered as a novel biomedical alloy. The wear resistance (H/Er) and anti-wear capability (H3/Er2) values of the four alloys are higher than those of the CP–Ti alloy (0.0238), which indicates that the present alloys have good wear resistance and anti-wear capability.

Effect of BN Short Fiber Content on Mechanical Properties of ZrB2-SiC UHTCs

2012 ◽  
Vol 512-515 ◽  
pp. 706-709 ◽  
Author(s):  
Chang Ling Zhou ◽  
Yan Yan Wang ◽  
Zhi Qiang Cheng ◽  
Chong Hai Wang ◽  
Rui Xiang Liu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Ceramic Composites ◽  
Short Fiber ◽  
Hot Pressing Sintering ◽  
Scanning Electron

ZrB2-20%volSiC ceramic composites with different volume of BN short fiber were fabricated by the hot-pressing sintering under 2000°C. The content of BN short fiber changed from 0 to 15vol%. The density, flexural strength, fracture toughness and thermal expansions coefficient were studied. The microstructures of the samples were observed by scanning electron microscopy. The results show that the introducing of BN short fiber into the ZrB2-20%volSiC lead to a serious of change to the mechanical properties of the ceramic. When the content of the BN short fiber is 10vol%, the flexural strength and fracture toughness reach 422.1MPa and 6.15 MPa•m 1/2 respectively. And the mechanism of the increasing toughness was studied.

Fracture Toughness and Adhesion Energy of Sol-gel Coatings on Glass

2002 ◽  
Vol 17 (1) ◽  
pp. 224-233 ◽  
Author(s):  
Jaap Den Toonder ◽  
Jürgen Malzbender ◽  
Gijsbertus De With ◽  
Ruud Balkenende
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Sol Gel ◽  
Industrial Applications ◽  
Adhesion Energy ◽  
Scratch Testing ◽  
New Methods ◽  
Quantitative Results ◽  
Coating Fracture

The reliability of coatings that are used in industrial applications critically depends on their mechanical properties. Nanoindentation and scratch testing are well-established techniques to measure some of these properties, namely the elastic modulus and hardness of coatings. In this paper, we investigate the possibility of also assessing the coating fracture toughness and the energy of adhesion between the coating and the substrate using indentation and scratch testing. Various existing and new methods are discussed, and they are illustrated by measurements on particle-filled sol-gel coatings on glass. All methods are based on the occurrence of cracking, and they are therefore only applicable to coating systems that act like brittle materials and exhibit cracking during indentation and scratching. The methods for determining the fracture toughness give comparable results, but the values still differ to within about 50%. The values of the adhesion energy obtained from different measurements are consistent, but it remains uncertain to which extent the obtained values are quantitatively correct. The results show that the methods used are promising, but more research is needed to obtain reliable quantitative results.

Microstructure and Mechanical Properties of SiC Whisker-Reinforced ZrB2 Ultra-High Temperature Ceramic

2008 ◽  
Vol 368-372 ◽  
pp. 1730-1732 ◽  
Author(s):  
Ping Hu ◽  
Xing Hong Zhang ◽  
Jie Cai Han ◽  
Song He Meng ◽  
Bao Lin Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperature ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Room Temperature ◽  
Pressing Temperature ◽  
Sintering Time ◽  
Microstructure And Mechanical Properties ◽  
Ultra High Temperature

SiC whisker-reinforced ZrB2 matrix ultra-high temperature ceramic were prepared at 2000°C for 1 h under 30MPa by hot pressing and the effects of whisker on flexural strength and fracture toughness of the composites was examined. The flexural strength and fracture toughness are 510±25MPa and 4.05±0.20MPa⋅m1/2 at room temperature, respectively. Comparing with the SiC particles-reinforced ZrB2 ceramic, no significant increase in both strength and toughness was observed. The microstructure of the composite showed that the SiC whisker was destroyed because the SiC whisker degraded due to rapid atom diffusivity at high temperature. The results suggested that some related parameters such as the lower hot-pressing temperature, a short sintering time should be controlled in order to obtain SiC whiskerreinforced ZrB2 composite with high properties.

Preliminary Research on Manufacturing Technology of Thin Bamboo Veneer Consolidated Composite Floor

2012 ◽  
Vol 503-504 ◽  
pp. 74-77
Author(s):  
Nan Hu ◽  
Xian Jun Li ◽  
Yi Qiang Wu ◽  
Xin Gong Li ◽  
Zhi Cheng Xue
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Bond Strength ◽  
Hot Pressing ◽  
Physical And Mechanical Properties ◽  
Pressing Pressure ◽  
Pressing Temperature ◽  
Decorative Material ◽  
Preliminary Research ◽  
Surface Bond

In this paper, the new bamboo-based consolidated composite floors were fabricated with thin bamboo veneers which used as decoration layers, wear resistant layers, high density fiberboards and equilibrium layers through assembling and scuffing. The effect rules of the composite floor on properties were preliminarily studied by three factors: hot-pressing temperature, pressure and time. The results showed that the wear resistance and surface bond strength of the thin bamboo veneer consolidated composite floor significantly increased with the rise of hot-pressing temperature. In the scope of resources, the effect of hot-pressing pressure and time on properties of the floor is not significant. The optimizing technology is hot-pressing temperature 170°C, pressure 3MPa and time 40s/mm in this study. The thin bamboo veneer consolidated composite floor is an excellent floor decorative material, which has good physical and mechanical properties.

Reactive Synthesis and Mechanical Properties of ZrB2-SiC-ZrC Composites

2008 ◽  
Vol 368-372 ◽  
pp. 1758-1760 ◽  
Author(s):  
Wen Wen Wu ◽  
Guo Jun Zhang ◽  
Yan Mei Kan ◽  
Pei Ling Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Raw Materials ◽  
Reactive Synthesis ◽  
Reactive Hot Pressing

ZrB2-SiC based composites with 0,5 and 15 vol% addition of ZrC were synthesized via reactive hot pressing at 1800°C using Zr, Si and B4C as raw materials. The mechanical properties of the composites were investigated. The composite of ZSC15 that contained 15 vol% of ZrC has the highest hardness. ZSC5 with 5 vol% of ZrC owns a most homogenous microstructure and the highest fracture toughness and flexural strength.

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