Microstructure and Mechanical Properties of Al2O3-TaCw Ceramic Cutting Tool Materials

2013 ◽  
Vol 797 ◽  
pp. 172-176
Author(s):  
Guo Long Zhao ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou ◽  
Hong Tao Zhu ◽  
...  

Three kinds of in-situ growth TaC whiskers toughening Al2O3 matrix ceramic cutting tool materials were prepared by two steps, which were in-situ synthesis of TaC whiskers in Al2O3 matrix powder by carbothermal reduction process and hot pressing of the composites respectively. The preparation process, microstructure, mechanical properties and toughening mechanisms of the composites were investigated. The in-situ synthesized TaC whiskers had a diameter of 0.1-0.5μm and an aspect ratio of 10-30. The composite containing 20vol.% TaC had the optimal comprehensive mechanical properties with flexural strength of 638MPa, fracture toughness of 6.5MPa·m1/2 and hardness of 17.4GPa. The improvement of the mechanical properties was attributed to the TaC particles and whiskers which induced the toughening and strengthening effects such as crack deflection, crack branching, grain and whisker fracture, interface debonding and whisker pullout. The fracture mode of the composites was the combination of intergranular and transgranular fracture which also improved the mechanical properties of the composites.

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.


2013 ◽  
Vol 589-590 ◽  
pp. 337-341 ◽  
Author(s):  
Yue Liu ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou ◽  
Peng Yao ◽  
...  

Ti(C,N)-TiB2-WC composite ceramic cutting tool materials with nano-scale additives Ni and Mo, and micro-scale additives Ni and Mo as sintering aids were sintered respectively at a temperature of 1550 °C for holding time of 1hour in vacuum by a hot-press technique. The effects of nano-scale additives Ni and Mo, and micro-scale additives Ni and Mo on microstructure and mechanical properties of composites were compared and investigated. It is concluded that the wettability of nano-scale Ni and Mo to the composites is better than that of micro-scale Ni and Mo. The nano-scale whiskers were found in the composite ceramic tool materials with nano-scale additives. The addition of nano-scale Ni and Mo instead of micro-scale Ni and Mo could make the flexural strength and fracture toughness of Ti(C, N)-TiB2 –WC composites have a promotion, but could not make the hardness of the composites increase in this study.


2006 ◽  
Vol 315-316 ◽  
pp. 706-709 ◽  
Author(s):  
Li Qiang Xu ◽  
Chuan Zhen Huang ◽  
Sui Lian Wang ◽  
Zeng Wen Liu

The effect of sintering temperature on mechanical properties and microstructure of rare earth oxides toughened Ti(C,N) ceramic cutting tool materials was investigated. The results showed that the mechanical properties of Ti(C,N) based ceramics were greatly influenced by sintering temperature. As a result, both of the density and mechanical properties of the materials sintered at 1350 and 1400 are worse than those sintered at 1450 and 1500. Low sintering temperature results in low density and degraded mechanical properties, but too high sintering temperature results in the precipitation of bond metal and thus reduces its fracture toughness. Intergranular fracture mode of the material is mainly observed.


Wear ◽  
1989 ◽  
Vol 133 (2) ◽  
pp. 309-321 ◽  
Author(s):  
S.-T. Buljan ◽  
S.F. Wayne

Sign in / Sign up

Export Citation Format

Share Document