Influence of Hot Pressing Sintering Temperature and Time on Microstructure and Mechanical Properties of TiB2/Al2O3 Tool Materials

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.

2008 ◽  
Vol 368-372 ◽  
pp. 1730-1732 ◽  
Author(s):  
Ping Hu ◽  
Xing Hong Zhang ◽  
Jie Cai Han ◽  
Song He Meng ◽  
Bao Lin Wang

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.


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 512-515 ◽  
pp. 706-709 ◽  
Author(s):  
Chang Ling Zhou ◽  
Yan Yan Wang ◽  
Zhi Qiang Cheng ◽  
Chong Hai Wang ◽  
Rui Xiang Liu

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.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2046 ◽  
Author(s):  
Yi Jing ◽  
Hongbing Yuan ◽  
Zisheng Lian

ZrB2–HfC ceramics have been fabricated using the liquid phase sintering technique at a sintering temperature as low as 1750 °C through the addition of Ni. The effects of HfC addition on the microstructure and mechanical properties of ZrB2–based ceramics have been investigated. These ceramics were composed of ZrB2, HfC, Ni, and a small amount of possible (Zr, Hf)B2 solid solution. Small HfC grains were distributed among ZrB2 grain boundaries. These small grains could improve the density of ZrB2–based ceramics and play a pinning role. With HfC content increasing from 10 wt % to 30 wt %, more HfC grains were distributed among ZrB2 grain boundaries, leading to weaker interface bonding among HfC grains; the relative density and Vickers hardness increased, and flexural strength and fracture toughness decreased. The weak interface bonding for 20 and 30 wt % HfC contents was the main cause of the decrease in both flexural strength and fracture toughness.


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.


2008 ◽  
Vol 368-372 ◽  
pp. 1764-1766 ◽  
Author(s):  
Yu Jin Wang ◽  
Lei Chen ◽  
Tai Quan Zhang ◽  
Yu Zhou

The ZrC-W composites with iron as sintering additive were fabricated by hot-press sintering. The densification, microstructure and mechanical properties of the composites were investigated. The incorporation of Fe beneficially promotes the densification of ZrC-W composites. The relative density of the composite sintered at 1900°C can attain 95.3%. W2C phase is also found in the ZrC-W composite sintered at 1700°C. The content of W2C decreases with the increase of sintering temperature. However, W2C phase is not identified in the composite sintered at 1900°C. The flexural strength and fracture toughness of the composites are strongly dependent on sintering temperature. The flexural strength and fracture toughness of ZrC-W composite sintered at optimized temperature of 1800°C are 438 MPa and 3.99 MPa·m1/2, respectively.


2010 ◽  
Vol 434-435 ◽  
pp. 173-177 ◽  
Author(s):  
Bao Xia Ma ◽  
Wen Bo Han ◽  
Xing Hong Zhang

Ternary ZrC-SiC-ZrB2 ceramic composites were prepared by hot pressing at 1900 °C for 60 min under a pressure of 30 MPa in argon. The influence of ZrB2 content on the microstructure and mechanical properties of ZrC-SiC-ZrB2 composites was investigated. Examination of SEM showed that the microstructure of the composites consisted of the equiaxed ZrB2, ZrC and SiC grains, and there was a slight tendency of reduction for grain size in ZrC with increasing ZrB2 content. The hardness increased considerably from 23.3 GPa for the ZS material to 26.4 GPa for the ZS20B material. Flexural strength was a strong function of ZrB2 content, increasing from 407 MPa without ZrB2 addition to 627 MPa when the ZrB2 content was 20vol.%. However, the addition of ZrB2 has little influence on the fracture toughness, ranging between 5.5 and 5.7 MPam1/2.


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.


2010 ◽  
Vol 658 ◽  
pp. 352-355 ◽  
Author(s):  
Hong Feng Yin ◽  
Lin Lin Lu

Ti3SiC2/SiC composites were fabricated by reactive hot pressing method. Effect of processing condition on the microstructure and mechanical properties of the composites were investigated. The results showed that: (1) Hot-pressing temperature influenced the phase constituent of Ti3SiC2/SiC composites. The flexural strength and fracture toughness of composites increased with hot pressing temperature. (2) The flexural strength and fracture toughness of composites increased when the content of SiC was increased. When the SiC content was 30wt% the flexural strength and fracture toughness of Ti3SiC2/SiC composite were 371MPa and 6.9MPa•m1/2 respectively. However, when the content of SiC reached 50wt%, the flexural strength and fracture toughness of composites decreased due to high porosity in the composites. (3) The flexural strength and fracture toughness of composites increased with the particle size of SiC added in composites. (4) Ti3SiC2/SiC composites were non-brittle at room temperature.


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