Microstructure and Mechanical Properties of MoSi2 Coating Deposited on Mo Substrate by Hot Dipping Processes

2019 ◽  
Vol 14 (12) ◽  
pp. 1680-1685 ◽  
Author(s):  
Yingyi Zhang ◽  
Shahid Hussain ◽  
Kun Cui ◽  
Tao Fu ◽  
Jie Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Important Influence ◽  
Strength Increase ◽  
Average Hardness ◽  
Microstructure And Mechanical Properties ◽  
Dipping Temperature ◽  
Mosi2 Coating ◽  
Dipping Process ◽  
Dipping Time

MoSi2 coating was deposited on Mo substrate by a hot dipping process within the silicon bath. The effects of the hot dipping temperature and time on the thickness and mechanical properties of MoSi2 coating have been investigated. The results indicated that the average hardness of MoSi2 coating is only 209.15 MPa, and the average flexural strength is 873.63 MPa. Therefore, the MoSi2 coating deposited on Mo substrate exhibit better mechanical properties than monolithic MoSi2 and MoSi2 -based composites. In addition, the hot dipping processes have an important influence on mechanical properties. The hardness and flexural strength decrease sharply with increasing hot dipping temperature, then increases slightly on increasing hot dipping temperature. Meanwhile, the hardness and flexural strength increase sharply with increasing hot-dipping time.

Effects of Sintering Additives on the Microstructure and Mechanical Properties of Silicon Nitride Ceramics by GPS

2010 ◽  
Vol 105-106 ◽  
pp. 27-30 ◽  
Author(s):  
Wei Ru Zhang ◽  
Feng Sun ◽  
Ting Yan Tian ◽  
Xiang Hong Teng ◽  
Min Chao Ru ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Transformation ◽  
Silicon Nitride ◽  
Porous Silicon ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Additives ◽  
Microstructure And Mechanical Properties ◽  
Nitride Ceramics

Silicon nitride ceramics were prepared by gas pressure sintering (GPS) with different sintering additives, including La2O3, Sm2O3 and Al2O3. Effect of sintering additives on the phase-transformation, microstructure and mechanical properties of porous silicon nitride ceramics was investigated. The results show that the reaction of sintering additives each other and with SiO2 had key effects on the phase-transformation, grain growing and grain boundaries. With 9MPa N2 atmosphere pressure, holding 1h at 1850°C, adding 10wt% one of the La2O3, Sm2O3, Al2O3, porous silicon nitride was prepared and the relative density was 78%, 72%, 85% respectively. The flexural strength was less than 500MPa, and the fracture toughness was less than 4.8MPam1/2. Dropping compounds sintering additives, such as La2O3+Al2O3, Sm2O3+Al2O3 effectively improves the sintering and mechanical properties. The relative density was 99.2% and 98.7% with 10wt% compounds sintering additives. The grain ratio of length to diameter was up to 1:8. The flexural strength was more than 900MPa, and the fracture toughness was more than 8.9MPam1/2.

scholarly journals Preparation and Performance of Al2O3/Ti(C,N)-Added ZrO2 Whisker and NanoCoated CaF2@Al(OH)3 Powder

2020 ◽  
Vol 10 (13) ◽  
pp. 4435
Author(s):  
Qi Li ◽  
Guangchun Xiao ◽  
Zhaoqiang Chen ◽  
Runxin Guo ◽  
Mingdong Yi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transition ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Ceramic Material ◽  
Microstructure And Mechanical Properties ◽  
And Performance

The Al2O3/Ti(C,N) ceramic material added micron ZrO2 whisker and nano coated CaF2@Al(OH)3 powder was fabricated. The micron ZrO2 whisker was for the toughening and reinforcing phase and the nano coated CaF2@Al(OH)3 powder was the lubricant. For obtaining a ceramic material with optimal comprehensive mechanical properties and friction properties, the influences of different compositions of the ZrO2 whisker and nano coated CaF2@Al(OH)3 powder on the microstructure and mechanical properties were analyzed, respectively. The result demonstrated that as the addition of the ZrO2 whisker was 6 vol% and the addition of the nano coated CaF2@Al(OH)3 powder was 10 vol%, the optimal self-lubricating ceramic material had optimal mechanical properties. The hardness of the ceramic material was 16.72 GPa, the flexural strength was 520 MPa and the fracture toughness reached 7.16 MPa·m1/2. The formation of the intragranular structure, whisker toughening and the phase transition of ZrO2 were the main mechanisms.

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.

scholarly journals Microstructure and Mechanical Properties of ZrB2–HfC Ceramics Influenced by HfC Addition

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2046 ◽  
Author(s):  
Yi Jing ◽  
Hongbing Yuan ◽  
Zisheng Lian
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Grain Boundaries ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Weak Interface ◽  
Interface Bonding ◽  
Microstructure And Mechanical Properties ◽  
Small Grains

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.

Microstructure and Properties of Hot-Pressing Sintered Tungsten Carbide Composites by Adding Cubic Boron Nitride

2015 ◽  
Vol 655 ◽  
pp. 45-48
Author(s):  
Kun Li ◽  
Hai Yan Chen ◽  
Qiu Shuang He ◽  
Li Hua Dong
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Flexural Strength ◽  
Tungsten Carbide ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Cubic Boron Nitride ◽  
Microstructure And Mechanical Properties ◽  
Hot Pressing Sintering ◽  
Sintering Method

(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.

Effect of Iron Additive on the Sintering Behavior of Hot-Pressed ZrC-W Composites

2008 ◽  
Vol 368-372 ◽  
pp. 1764-1766 ◽  
Author(s):  
Yu Jin Wang ◽  
Lei Chen ◽  
Tai Quan Zhang ◽  
Yu Zhou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Sintering Behavior ◽  
Hot Press ◽  
Sintering Additive ◽  
Microstructure And Mechanical Properties ◽  
Hot Press Sintering

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.

Effects of Nano-ZrO2 on the Microstructure and Mechanical Properties of Ti(C,N)-Based Cermet Die Materials

2010 ◽  
Vol 154-155 ◽  
pp. 1319-1323 ◽  
Author(s):  
Xing Hai Wang ◽  
Chong Hai Xu ◽  
Ming Dong Yi ◽  
Hui Fa Zhang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Flexural Strength ◽  
Weight Percent ◽  
Environmental Scanning ◽  
Microstructure And Mechanical Properties ◽  
Vacuum Atmosphere ◽  
Die Materials ◽  
Scanning Electron

In recent, the development of new die materials is one of the important topics in the field of die research. In this paper, effects of nano-ZrO2 addition on the microstructure and mechanical properties of Ti(C,N)-based cermets were studied. The newly developed Ti(C,N)-based cermet die materials with different contents of nano-ZrO2 of 0~25wt% were prepared by hot pressing technique under vacuum atmosphere at 1450°C for 30min. Moreover, the microstructure of this Ti(C,N)-based cermet die materials was observed by environmental scanning electron microscope. It indicates that the comprehensive mechanical properties can reach the optimum when the weight percent of the nano-ZrO2 is 10%. The corresponding flexural strength and fracture toughness is 967 MPa and 13.62 MPa•m1/2, respectively which is approximately 65% and 110% higher than that of the cermet without nano-ZrO2 addition. It suggests that the addition of nano-ZrO2 can improve the mechanical properties especially the fracture toughness and flexural strength of Ti(C,N)-based cermet die materials.

Microstructure and Mechanical Properties of Hot Pressed ZrC-SiC-ZrB2 Composites

2010 ◽  
Vol 434-435 ◽  
pp. 173-177 ◽  
Author(s):  
Bao Xia Ma ◽  
Wen Bo Han ◽  
Xing Hong Zhang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Ceramic Composites ◽  
Strong Function ◽  
Slight Tendency ◽  
Microstructure And Mechanical Properties

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.

Influence of Hot Pressing Temperature and SiC Content on the Microstructure and Mechanical Properties of ZrB2-SiC

2010 ◽  
Vol 434-435 ◽  
pp. 189-192
Author(s):  
Yong Zhang ◽  
Ping Hu ◽  
Xing Hong Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Volume Percent ◽  
Pressing Temperature ◽  
Sic Ceramics ◽  
Opposite Trend ◽  
Microstructure And Mechanical Properties ◽  
Dense Ceramic

The influence of hot pressing temperature and SiC content on the microstructure and mechanical properties of ZrB2-SiC ceramics was investigated. ZrB2 containing 20 volume percent SiC were prepared by hot pressing at 1850, 1900 and 1950°C for 60 min. Fully dense ceramic was obtained after hot pressing at temperature of 1950°C. In addition, the materials with SiC content of 0, 10vol.%, 15 vol.%, 20 vol.% and 30 vol.% hot pressed at 1950°C were also investigated. Results showed that the grain size of the ZrB2 significantly reduced on adding 10vol.% SiC and then decreased slightly with further increasing SiC content, whereas the grain size of SiC exhibited a opposite trend. The flexural strength of ZrB2-SiC ceramics remarkedly increased on adding 10vol.% SiC due to the significant decrease of ZrB2 particle size and then slightly increased with increasing SiC content up to 20vol.%. However, further increasing SiC content led to a reduction of the flexural strength.

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