Effect of Pressure on TiB2-Cu Composite via In-Situ Reaction Synthesis

2007 ◽  
Vol 280-283 ◽  
pp. 1437-1440
Author(s):  
Yue Feng Sun ◽  
Qiang Xu ◽  
Xing Hong Zhang ◽  
Jie Cai Han ◽  
Jin Huai Liu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Exothermic Reaction ◽  
Applied Pressure ◽  
Reaction Synthesis ◽  
Matrix Composites ◽  
Copper Powders ◽  
Fine Microstructure

TiB2-Cu matrix composites from titanium, boron and copper powders were in-situ fabricated by exothermic reaction. The effect of the applied pressure on the mechanical properties of the composite was investigated. The results showed that when the applied pressure increasing, the relative density, bending strength, fracture toughness and hardness of the composites were on the increase due to the formation of fine microstructure and the improvement of densification with the pressure increasing. The high pressure is beneficial to the better mechanical properties.

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.

Microstructure and Mechanical Properties of Al2O3/NiAl In Situ Composites by Hot-Press-Aided Reaction Synthesis

2012 ◽  
Vol 581-582 ◽  
pp. 548-551 ◽  
Author(s):  
Guo Quan Qi ◽  
Feng Shou Shangguan ◽  
Li Neng Yang ◽  
Qiang Bai ◽  
Gang Wu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Vickers Hardness ◽  
Elemental Powder ◽  
Reaction Synthesis ◽  
Hot Press ◽  
Dispersion Method ◽  
Powder Mixtures

Al2O3/NiAl composites were successfully fabricated by hot-press-assisted exothermic dispersion method with elemental powder mixtures of Ni, Al, NiO. The content of Al2O3 on the microstructures and mechanical properties of Al2O3/NiAl composites has been characterized. The results show that the Vickers hardness, flexural strength and fracture toughness of the composites increase with increasing Al2O3 content. When the Al2O3 content is 15 wt %, the flexural strength and the fracture toughness peaked at 765 MPa and 9.67 MPa•m 1/2, respectively. The improvement of mechanical properties is associated with a more homogeneous and finer microstructure developed by addition of Al2O3.

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.

scholarly journals Effect of Ti Addition on the Microstructure and Mechanical Properties of SiC Matrix Composites Infiltrated by Al–Si (10 wt.%)–xTi Alloy

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 318
Author(s):  
Yajun Yu ◽  
An Du ◽  
Xue Zhao ◽  
Yongzhe Fan ◽  
Ruina Ma ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Intermetallic Compounds ◽  
Bending Strength ◽  
Al Alloys ◽  
Al Alloy ◽  
Matrix Composites ◽  
Sic Ceramics ◽  
Microstructure And Mechanical Properties ◽  
Ti Addition

This paper proposes a simple reactive melt infiltration process to improve the mechanical properties of silicon carbide (SiC) ceramics. SiC matrix composites were infiltrated by Al–Si (10 wt.%)–xTi melts at 900 °C for 4 h. The effects of Ti addition on the microstructure and mechanical properties of the composites were investigated. The results showed that the three-point bending strength, fracture toughness (by single-edge notched beam test), and fracture toughness (by Vickers indentation method) of the SiC ceramics increased most by 34.3%, 48.5%, and 128.5%, respectively, following an infiltration with the Al–Si (10 wt.%)–Ti (15 wt.%) melt. A distinct white reaction layer mainly containing a Ti3Si(Al)C2 phase was formed on the surface of the composites infiltrated by Al alloys containing Ti. Ti–Al intermetallic compounds were scattered in the inner regions of the composites. With the increase in the Ti content (from 0 to 15 wt.%) in the Al alloy, the relative contents of Ti3Si(Al)C2 and Ti–Al intermetallic compounds increased. Compared with the fabricated composite infiltrated by an Al alloy without Ti, the fabricated composites infiltrated by Al alloys containing Ti showed improved overall mechanical properties owing to formation of higher relative content Ti3Si(Al)C2 phase and small amounts of Ti–Al intermetallic compounds.

Influence of Cr2O3 Addition on the Properties of TiAl Composites

2011 ◽  
Vol 230-232 ◽  
pp. 789-792
Author(s):  
Jian Feng Zhu ◽  
Wen Wen Yang ◽  
Fang Ni Du
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Synthesis Method ◽  
Strengthening Mechanism ◽  
Reaction Synthesis ◽  
The Matrix ◽  
Method Effects ◽  
Particulate Reinforced

Using Ti, Al and Cr2O3 as starting materials, Al2O3 particulate reinforced TiAl composites have been fabricated by in-situ reaction synthesis method. Effects of the Cr2O3 addition on the microstructures and mechanical properties of the TiAl/Al2O3 composites were investigated in detail. The results show that the composites have a matrix of TiAl, Ti3Al, and minor Cr containing phases, and a second reinforcement Al2O3. The addition of Cr2O3 effectively refined the structure of the matrix, and as a result, the mechanical properties of TiAl composites are improved. At Cr2O3 7.36 wt%, the flexural strength and fracture toughness reach the maximum values of 634.62 MPa and 9.79 MPa·m1/2, which are increased by 80% and 30%, respectively. The strengthening mechanism is also discussed.

Effects of Rapid Heat Treatment on Microstructure and Mechanical Properties of Ti2AlC/TiAl Composite

2007 ◽  
Vol 336-338 ◽  
pp. 1164-1167
Author(s):  
Yun Long Yue ◽  
Hai Tao Wu ◽  
Wei Bing Wu ◽  
Hai Yan Yin
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Duplex Microstructure ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Rapid Heat Treatment

In this paper Ti2AlC/TiAl composites were in-situ fabricated by spark plasma sintering (SPS) and then the effects of rapid heat-treatment on microstructure and mechanical properties of Ti2AlC/TiAl composites were investigated. After rapid heat-treatment the microstructure of TiAl matrix was significantly transformed from the near γ microstructure to duplex microstructure. Ti2AlC particles effectively refined the γ phase grains and the α2/γ lamellar colony microstructure. For the Ti2AlC/TiAl composite after rapid heat-treatment at 1200°C, the bending strength and fracture toughness reached 956.8MPa and 22.8MPa·m1/2, respectively.

Deformation and Fracture Mechanics of Superior Nanocomposites

2020 ◽  
Vol 990 ◽  
pp. 244-249
Author(s):  
Lydia Anggraini
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
High Hardness ◽  
High Energy ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Fine Grained ◽  
Deformation And Fracture ◽  
Fine Microstructure

Lightweight ultra-fine grained (<1 μm size) SiC-ZrO2(3Y2O3) composites, with a combination of high hardness, high bending strength and high fracture toughness, were successfully prepared by high energy mechanical milling followed by heat treatment. The SiC-ZrO2(3Y2O3) composites exhibitied high hardness (1707 MPa), high bending strengh (as high as 1689 MPa) and high fracture toughness (up to approximately 12.6 MPa.m1/2). Such a combination of mechanical properties was attributed to the fine microstructure with a distinct feature consisting of almost continuous network of ZrO2(3Y2O3) phase around SiC grains, or we call harmonic microstructure. It has been demonstrated that a combination of these unique microstructural characteristics was very effective in supressing the initiation of cracks and governing the path of their subsequent growth during fracture, leading to excellent combination of mechanical properties.

Investigation of Ni3Al-matrix composites strengthened by TiC

1993 ◽  
Vol 8 (11) ◽  
pp. 2830-2834 ◽  
Author(s):  
Bingchu Mei ◽  
Runzhang Yuan ◽  
Xinlong Duan
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
High Temperature ◽  
Bending Strength ◽  
Melting Process ◽  
Matrix Composites ◽  
High Temperature Synthesis ◽  
Al Matrix Composites ◽  
Al Matrix

In this paper, the possibilities of preparing TiC-reinforced Ni3Al-matrix composites by SM (self-propagating high temperature synthesis and melting process) were examined. Two kinds of composites, namely, commercial TiC-reinforcement and synthesized TiC-reinforcement Ni3Al-matrix composites, were fabricated. The effects of particle size of the commercial TiC on the mechanical properties of the Ni3Al-matrix composites were studied. The results show that the mechanical properties of the composites decrease with increasing particle size of the commercial TiC. The microstructures of 35 wt. % TiC + 65 wt. % Ni3Al composites produced by SM technology from the four elements Ti, C, Ni, and Al were examined. The results show that in these composites, the particle size of TiC synthesized in situ is fine and that the materials have considerable high-temperature bending strength and fracture toughness.

scholarly journals Effects of directly added or reaction formed TiB2 on the microstructure and mechanical properties of pressureless-sintered B4C–TiB2 composites

2020 ◽  
Author(s):  
Zongjia Li ◽  
Yangwei Wang ◽  
Huanwu Cheng ◽  
Yu Zhu ◽  
Rui An ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Boron Carbide ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Submicron Particles ◽  
Matrix Composites ◽  
Effective Role ◽  
Carbide Matrix ◽  
Sintering Method

Abstract The boron carbide matrix composites containing boron carbide (B 4 C), titanium diboride (TiB 2 ; 20 wt% and 30 wt%) and titanium carbide (TiC) were fabricated at 2130 °C using the pressureless sintering method. Different amounts of TiB 2 and TiC particles were added to B 4 C, and the TiB 2 content was chosen as the main variable to study the effect on the composites. The density, hardness, bending strength and fracture toughness measurements were performed to obtain the physical and mechanical properties of the samples. The obtained results indicate that by adding 30 wt% TiB 2 submicron particles at 2130 °C, the bending strength and fracture toughness of 277.6 MPa and 5.38 MPa·m 1/2 are obtained for the composite. The particle pullout and crack microbridging play an effective role in toughening the composite ceramics. The main toughening mechanisms of the B 4 C-TiB 2 composites are noted to be microcrack and crack deflection toughening owing to the residual stresses resulting from the mismatch of the thermal expansion coefficient between TiB 2 and B 4 C.

Effects of Nb2O5/La2O3 Synergistic Modification on Phase Composition, Microstructure and Mechanical Properties of Al2O3 Ceramics Prepared by Microwave Sintering

2014 ◽  
Vol 633 ◽  
pp. 49-52
Author(s):  
Yun Long Ai ◽  
Kai Wu ◽  
Xiang Hua Xie ◽  
Bing Liang Liang ◽  
Wen He ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Bending Strength ◽  
Microwave Sintering ◽  
Composite Ceramic ◽  
Composite Ceramics ◽  
Comprehensive Properties ◽  
Microstructure And Mechanical Properties

Nb2O5-7.5La2O3-Al2O3 composite ceramics were prepared by microwave sintering. The influence of Nb2O5 and La2O3 proportion on the microstructure and mechanical properties of Al2O3 ceramics was investigated. The results show that when the Nb2O5 content was lower than La2O3, the columnar LaAl11O18 grains were generated by the reaction of La2O3 with Al2O3. When the Nb2O5 content was higher than La2O3, the surplus Nb2O5 induced the formation of columnar Al2O3 grains. The growth of columnar Al2O3 grains were promoted synergistically by LaNbO4 formed in-situ and Nb2O5. The 5Nb2O5-7.5La2O3-Al2O3 composite ceramic exhibited excellent comprehensive properties: ρr=99.3% (relative density), HV=11.2GPa (microhardness), KIC= 6.4MPa·m1/2 (fracture toughness), σ=304.3MPa (bending strength).

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