Microstructure and Mechanical Properties of TiC/Ti3AlC2 In Situ Composites Prepared by Hot Pressing Method

2015 ◽  
Vol 816 ◽  
pp. 200-204 ◽  
Author(s):  
Miao Miao Ruan ◽  
Xiao Ming Feng ◽  
Tao Tao Ai ◽  
Ning Yu ◽  
Kui Hua

TiC/Ti3AlC2 composites were successfully prepared by hot-pressing sintering method from the elemental powder mixtures of Ti, Al and TiC. A possible reaction mechanism was investigated by XRD. The density, Vickers hardness, flexural strength, and fracture toughness of the TiC/Ti3AlC2 composites were also measured. At 660 °C, Al melted and reacted with Ti to form TiAl3. At 900 °C, TiAl3 reacted with TiC and Ti to form Ti2AlC. At 1100 °C, Ti2AlC reacted with TiC to form Ti3AlC2. Increasing the sintering temperature, the content of Ti3AlC2 increased. The TiC/Ti3AlC2 composites had excellent performance after sintered at 1100 °C, the density, Vickers hardness, flexural strength and fracture toughness of the composite were 4.35 g/cm3, 4.72 GPa, 566 MPa and 6.18 MPa·m1/2, respectively.

2011 ◽  
Vol 675-677 ◽  
pp. 597-600
Author(s):  
Liu Yi Xiang ◽  
Fen Wang ◽  
Jian Feng Zhu ◽  
Xiao Feng Wang

Al2O3/TiAl in situ composites were successfully prepared by vacuum hot-pressing method with elemental powder mixtures of Ti, Al, TiO2 and Fe2O3. The effect of Fe2O3 addition on the microstructures and mechanical properties of Al2O3/TiAl composites has been investigated. The results show that the Rockwell hardness, flexural strength and fracture toughness of the composites increase with increasing Fe2O3 content. When the Fe2O3 content is 0.84 wt %, the flexural strength and the fracture toughness reach the maximum value of 624 MPa and 6.63 MPa·m1/2, respectively. The improvement of mechanical properties is firstly associated with a more homogeneous and finer microstructure developed by addition of Fe2O3; secondly, it is related to the increase of the ratio of α2-Ti3Al/γ- TiAl matrix phases.


2015 ◽  
Vol 655 ◽  
pp. 45-48
Author(s):  
Kun Li ◽  
Hai Yan Chen ◽  
Qiu Shuang He ◽  
Li Hua Dong

(0, 5, 10, 15, 20) vol% CBN-WC/Co composites were consolidated by ball milling and the following hot-pressing sintering method. WC, Co and CBN powders were used as the starting materials. The effects of the CBN content on the density, microstructure and mechanical properties of CBN-WC/Co composites were investigated. The results showed that the CBN content had remarkable influence on the microstructure and mechanical properties of CBN-WC/Co Composites. With the increasing content of CBN, the density decrease, while Vickers hardness and flexural strength increased initially to the maximum values and then decreased at CBN 10 vol%. When 10 vol% CBN-WC/Co powders were hot-pressing sintered at 1350°C and 20MPa for 90 min, an excellent Vickers hardness of 19.8GPa was achieved, combining a flexural strength of 682MPa.


2012 ◽  
Vol 581-582 ◽  
pp. 548-551 ◽  
Author(s):  
Guo Quan Qi ◽  
Feng Shou Shangguan ◽  
Li Neng Yang ◽  
Qiang Bai ◽  
Gang Wu

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.


2011 ◽  
Vol 695 ◽  
pp. 227-230
Author(s):  
Liu Yi Xiang ◽  
Fen Wang ◽  
Jian Feng Zhu ◽  
Xiao Feng Wang

Al2O3/TiAl composites were successfully fabricated by hot-press-assisted exothermic dispersion method with powder mixtures of Ti, Al, TiO2and Cr2O3as raw materials. The effect of sintering temperature on the microstructures and mechanical properties of Al2O3/TiAl composites has been investigated. The results show that the Rockwell hardness and density of the composites increased with increasing sintering temperature. But the flexural strength and fracture toughness peaked at 825 MPa and 7.29 MPa·m1/2, respectively, when the sintering temperature reached to1300 °C.


2012 ◽  
Vol 500 ◽  
pp. 629-633 ◽  
Author(s):  
Mei Lin Gu ◽  
Hong Jing Xu ◽  
Jian Hua Zhang ◽  
Zhi Wei

In this paper, a TiB2/Al2O3composite was hot-pressed. The effect of hot pressing parameters on the TiB2/Al2O3composite microstructure and mechanical properties was investigated. The flexural strength and fracture toughness were measured by three point bending testing and direct indentation method, respectively. Experimental results show that the flexural strength decreases consistently with an increase in the sintering time, however, the fracture toughness increases consistently with an increase in the sintering time and sintering temperature. The maximum of the flexural strength is 1072 MPa at 1530 sintering temperature and 60 min sintering time. The microstructures were revealed by means of SEM. The results show that the TiB2grain size and density increases with the increasing temperature and time during hot pressing sintering, which benefits the fracture toughness and flexural strength.


2012 ◽  
Vol 724 ◽  
pp. 278-281 ◽  
Author(s):  
Lan Ye ◽  
Jian Feng Zhu

The Ti3AlC2/Al2O3 in situ composites were successfully synthesized from the system of Ti-TiC-Al-TiO2 by reactive hot pressing at 1350 °C. The effect of TiC content on the phase composition, microstructure and mechanical properties were investigated in detail. The results indicate that the fabricated products possess the highest purity as the TiC contents reduce to 90 % of its theoretical content. This deviation is mainly attributed to the decomposition of Ti3AlC2 and vaporization of Al at high temperatures. The effect of TiC content on the fracture toughness, flexural strength, Vickers hardness of Ti3AlC2/Al2O3 composites was also discussed in detail.


2011 ◽  
Vol 233-235 ◽  
pp. 2272-2275
Author(s):  
Xin Yan Yue ◽  
Bi Shuang Chen ◽  
Jing Zhao ◽  
Hong Qiang Ru ◽  
Wei Wang

B4C ceramics were obtained using hot-pressing method. The effect of different sintering temperatures on the microstructures and mechanical properties of B4C ceramics were investigated. Oxidation resistances were studied over the range 600-850°C. The experimental results showed that the relative density, bending strength and fracture toughness all increased first and then decreased with increasing the sintering temperature. The Vickers-hardness increased as the sintering temperature increasing. When the sintering temperature was 1950°C, the B4C ceramics showed the optimized properties. The values of its relative density, Vickers-hardness, bending strength and fracture toughness were 99.1%, 34.0 GPa, 524.6 MPa and 6.56 MPa·m1/2, respectively.


2021 ◽  
Vol 1 (4) ◽  
pp. 216-222
Author(s):  
Sheida Haji Amiri ◽  
Nasser Pourmohammadie Vafa

The Ti3SiC2 used in this project has been purchased ready-made. This study aimed to investigate the effect of sintering temperature on samples' microstructure and mechanical properties, including three-point flexural strength, Vickers hardness, and fracture toughness. Therefore, Ti3SiC2 samples were sintered under a vacuum atmosphere at a pressure of 35 MPa for 30 minutes at two temperatures of 1500 °C and 1550 °C by hot pressing. The microstructure obtained from the fracture cross-section of the samples shows that by increasing the sintering temperature to 1550 °C, the microstructure of this sample becomes larger than the sintered sample at 1500 °C. Also, increasing the sintering temperature to 1550 °C causes the decomposition of Ti3SiC2 to TiC, which can be seen in the X-ray diffraction pattern (XRD). In addition, the relative density of the sintered sample at 1550 °C is 98.08% which is higher than that of the sintered sample at 1500 °C with the result of 89%. On the other hand, the three-point flexural strength (227.5 MPa), the Vickers hardness (~9 GPa), and the fracture toughness (8.6 MPa.m1/2) of the sintered sample at 1500 °C are higher due to the fine-grained structure.


2012 ◽  
Vol 724 ◽  
pp. 315-318 ◽  
Author(s):  
Jian Feng Zhu ◽  
Rui Juan Pan

Mo modified Ti2A1C /Al2O3 composites were successfully fabricated from an elemental power mixture of Ti, Al, TiC and MoO3 by an in situ reaction/hot pressing method. The reaction path and effect of the molar ratio of the initial materials on the phase composition were investigated in detail. The as-prepared materials are mainly composed of (Ti1-xMox)2AlC solid solutions, Al2O3, and a small amounts of the Mo rich compounds. It is found that the in situ formed fine Al2O3 particles tend to disperse on the matrix grain boundaries. Compared with the monolithic Ti2A1C, (Ti,Mo)2AlC/10 wt% Al2O3 composite possesses a fine grain sized structure. The Vickers hardness, flexural strength, fracture toughness, and compressive strength of the as composite are 4.75 GPa, 458 MPa, 6.03 MPa·m1/2, 971 MPa, respectively.


2015 ◽  
Vol 47 (3) ◽  
pp. 311-317 ◽  
Author(s):  
F. Wang ◽  
N. Fan ◽  
J. Zhu ◽  
H. Jiang

Al2O3/TiAl composites were successfully fabricated from powder mixtures of Ti, Al, TiO2, Cr2O3 and Nb2O5 by a hot-press-assisted exothermic dispersion method. The effect of the Cr2O3 and Nb2O5 addition on the microstructures and mechanical properties of Al2O3/TiAl composites was characterized. The results showed that the specimens are mainly composed of TiAl, Ti3Al, Al2O3, NbAl3 and Cr2Al. The Vicker-hardness and density of Al2O3/TiAl composites increase gradually with the increase of Nb2O5 content. When the Nb2O5 content was 6.54 wt %, the flexural strength and fracture toughness of the composites have a maximum values of 789.79 MPa and 9.69 MPa?m1/2, respectively. The improvement of mechanical properties is discussed in detail.


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