Study on the mechanical properties, microstructure and oxidation resistance of Si3N4/Si3N4W/Ti(C7N3) nanocomposites ceramic tool materials

Author(s):  
Bin Zou ◽  
Chuanzhen Huang ◽  
Ming Chen
2010 ◽  
Vol 431-432 ◽  
pp. 523-526
Author(s):  
Han Lian Liu ◽  
Chuan Zhen Huang ◽  
Shou Rong Xiao ◽  
Hui Wang ◽  
Ming Hong

Under the liquid-phase hot-pressing technique, the multi-scale titanium diboride matrix nanocomposite ceramic tool materials were fabricated by adding both micro-scale and nano-scale TiN particles into TiB2 with Ni and Mo as sintering aids. The effect of content of nano-scale TiN and sintering temperature on the microstructure and mechanical properties was studied. The result showed that flexural strength and fracture toughness of the composites increased first, and then decreased with an increase of the content of nano-scale TiN, while the Vickers hardness decreased with an increase of the content of nano-scale TiN. The optimal mechanical properties were flexural strength 742 MPa, fracture toughness 6.5 MPa•m1/2 and Vickers hardness 17GPa respectively. The intergranular and transgranular fracture mode were observed in the composites. The metal phase can cause ductility toughening and crack bridging, while crack deflection and transgranular fracture mode could be brought by micro-scale TiN and nano-scale TiN respectively.


2014 ◽  
Vol 800-801 ◽  
pp. 511-515
Author(s):  
Xian Hua Tian ◽  
Jun Zhao ◽  
Shuai Liu ◽  
Zhao Chao Gong

Close attention has been paid to Functional graded materials (FGMs) worldwide for their novel design ideas and outstanding properties. To verify the advantage of FGMS in the design of ceramic tool materials, Si3N4/(W, Ti)C nanocomposite ceramic tool materials with homogenous and graded structure were fabricated by hot pressing and sintering technology. The flexural strength, fracture toughness and hardness of the sintered composites were tested and compared. The experimental results showed that the graded structure improved mechanical properties of the ceramic tool materials, especially the flexural strength and fracture toughness. The introduction of residual compressive stress in the surface layer contributes to the improvement of the properties .


2004 ◽  
Vol 471-472 ◽  
pp. 221-224 ◽  
Author(s):  
Jian Xin Deng ◽  
Tong Kun Cao ◽  
Jia Lin Sun

Al2O3/TiC ceramic tool materials with the addition of solid lubricants such as BN and CaF2 were produced by hot pressing. Effect of the solid lubricants on the microstructure and mechanical properties has been studied. Results showed that AlN phase resulted from the reaction of Al2O3 with BN was formed in Al2O3/TiC/BN composite after sintering. Significant micro-cracks resulted from the residual stress owing to the difference in the thermal expansion coefficient were found on the polished surface, and caused large mechanical properties degradation. While Al2O3/TiC/CaF2 composite showed higher flexural strength, fracture toughness, and hardness compared with that of Al2O3/TiC/BN composite owing its porosity absent and finer microstructure.


2010 ◽  
Vol 150-151 ◽  
pp. 1358-1363
Author(s):  
Bin Fang ◽  
Chuan Zhen Huang ◽  
Chong Hai Xu ◽  
Sheng Sun

The fabrication is a key process for the preparation of ceramic tool materials, which governs the mechanical properties of ceramic tool materials under the condition of the same compositions. A computer simulation coupled with fabrication temperature for the hot-pressing process of single-phase ceramic tool materials has been developed using a two-dimensional hexagon lattice model mapped from the realistic microstructure without considering the presence of pores. The fabrication of single-phase Al2O3 is simulated. The mean grain size of simulated microstructure by Monte Carlo Potts model integrated with fabrication temperature increases with an increase in fabrication temperature, which is consistent with the experiment results.


2008 ◽  
Vol 375-376 ◽  
pp. 128-132
Author(s):  
Chuan Zhen Huang ◽  
Bin Zou ◽  
Han Lian Liu

A series of self-toughening silicon nitride matrix nanocomposite ceramic tool materials are fabricated by hot-press technology at different sintering processes. And their microstructure has been observed and analyzed by a scanning electron microscope (SEM). Finally, the tests of mechanical properties and the cutting performance of the new ceramics are presented. The research results showed that the nanocomposite ceramic tool materials GGW20T5 and GGW20TC25 have better mechanical properties and possess a stronger wear resistance in cutting 40Cr alloy steel.


2010 ◽  
Vol 65 ◽  
pp. 56-60 ◽  
Author(s):  
Gabriela Górny ◽  
Roman Pampuch ◽  
Ludosław Stobierski ◽  
Paweł Rutkowski

Frictional and mechanical properties of hot-pressed Al2O3 and Si3N4 - matrix composites containing up to 5 vol. % hexagonal BN as a solid lubricant. A very low coefficient of friction which is necessary for high-speed cutting has been observed. Fracture toughness remained constant with increase of h-BN content while flexural strength changes with the hBN content have been found to depend upon the material homogeneity. The work has been supported by EU Funds in Poland under contract UDA-POIG.01.03-12-024/08-00.and has been realized in the frame of scientific-industrial consortium.


2008 ◽  
Vol 375-376 ◽  
pp. 97-101 ◽  
Author(s):  
Bin Fang ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Chong Hai Xu

In order to investigate the effect of hot-press fabrication parameters on mechanical properties of Al2O3 ceramic tool materials, the orthogonal experiment method was used. In the experiments, the three influence factors such as the fabrication temperature, pressure and duration time are considered. The experimental results are analyzed by a range analysis of orthogonal experiments. It is shown that the most important factor that affects the mechanical properties is the fabrication temperature and the followed factors are the fabrication pressure and the duration time of fabrication. Scanning electron microscope (SEM) reveals that the hot-press fabrication parameters will significantly affect the microstructure of ceramic tool materials, which can govern the mechanical properties. This has been validated by the orthogonal experiments in the present paper.


2012 ◽  
Vol 723 ◽  
pp. 233-237 ◽  
Author(s):  
Tong Chun Yang ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou ◽  
Hong Tao Zhu ◽  
...  

TiB2-(W,Ti)C composites with (Ni,Mo) as sintering additive have been fabricated by hot-pressing technique, and the microstructure and mechanical properties of the composites have been investigated. (Ni,Mo) promotes grain growth of the composites. In the case of 7vol.% (Ni,Mo), the grain size decreases consistently with an increase in the content of (W,Ti)C. When the proper content of (W,Ti)C is added to TiB2 composites, the growth of matrix grains is inhibited and the mechanical properties of the composites are improved. The best mechanical properties of the composites are 1084.13MPa for three-point flexural strength, 7.80MPa•m 1/2 for fracture toughness and 17.92GPa for Vickers hardness.


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