scholarly journals Cohesive Element Model for Fracture Behavior Analysis of Al2O3/Graphene Composite Ceramic Tool Material

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 669 ◽  
Author(s):  
Yongpeng Zhang ◽  
Guangchun Xiao ◽  
Chonghai Xu ◽  
Tingting Zhou ◽  
Mingdong Yi ◽  
...  

The microstructure model of Al2O3/graphene (AG) composite ceramic tool material is established based on Voronoi tessellation. The cohesive element method was used to simulate the crack growth of AG. The effect of cohesive parameters at the grain boundary of Al2O3 and graphene on the crack propagation was investigated. The results show that the grain strength of graphene is too high, the crack propagation to graphene grains will be hindered and cannot propagate forward. Cracks tend to spread along the paths where the crack propagation drive force was high and the resistance was low. When the interface strength between Al2O3 and graphene was at the weak interface, the crack propagation path and length were relatively straight and short. The average energy release rate G C is 1.042 × 10−3 J/m2, which is 2.4% higher than that of single-phase Al2O3 ceramic tool materials. However, if the interface strength between Al2O3 and graphene was at the strong interface, the crack propagated along graphene particles for a short distance, consuming a large amount of fracture energy. Furthermore, the crack will deflect around graphene grains, which increases the crack propagation length. The average energy release rate G C is 1.039 × 10−3 J/m2, which is 2% higher than that of single-phase Al2O3 ceramic tool materials.

2004 ◽  
Vol 471-472 ◽  
pp. 21-25 ◽  
Author(s):  
Chong Hai Xu ◽  
Chuan Zhen Huang ◽  
Xing Ai

Thermal shock resistance is one of the primary properties for the ceramic cutting tool materials with perspectives in high speed machining. An optimum model for the compositional design of the composite ceramic tool materials is built based on the thermal shock resistance. The thermal stress fracture resistance factor R is used to characterize the thermal shock resistance of the ceramic material. Results show that the developed (W,Ti)C/SiC/Al2O3 multiphase ceramic tool material can be expected to achieve the highest thermal shock resistance when the volume fraction of (W,Ti)C and SiC is about 15.8% and 24.8%, respectively. Thermal fracture resistance of the (W,Ti)C/SiC/Al2O3 ceramic tool material is approximately 81-88% higher than that of the pure alumina ceramic when machining the hardened carbon steel, which coincides well with the theoretical prediction from the optimum model. It suggests that the method used here is feasible for the development of ceramic tool materials with designed thermal shock resistance.


2011 ◽  
Vol 335-336 ◽  
pp. 736-739
Author(s):  
Xing Li ◽  
Bin Fang ◽  
Xiu Guo Xu ◽  
Chong Hai Xu

The Al2O3(nm)/SiC(μm)/Al2O3(μm)ceramic tool materials were fabricated by the hot-pressing technique. Effect of the compositions on microstructure and mechanical properties is investigated. With nano-particles content decreasing, the flexural strength increased and fine grains can be obtained. When the nano-alumina content is 60wt%, the grain of this sample is fine, the Vickers hardness and flexural strength are 16.24 GPa and 678 MPa, respectively.


2011 ◽  
Vol 335-336 ◽  
pp. 688-694
Author(s):  
Xiao Hui Zhu ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou ◽  
Hong Tao Zhu

Based on the microstructure results of Monte Carlo simulation, a three-dimensional grid model is built up, and imported into the finite element software with C++ language to analyze the mechanical properties of ceramic tool material. The stress field and residual stress of single-phase and multiphase ceramics have been analyzed by the computer simulation technology.


2014 ◽  
Vol 1052 ◽  
pp. 86-90
Author(s):  
Song Hao ◽  
Chuan Zhen Huang

A phase field model of three-phase composite ceramic tool materials with two kinds of nanoparticles is set up in this research. The three-dimensional simulation algorithm is modified and a new efficient algorithm is established. The microstructure evolution of three-phase nanoceramic tool materials is more efficiently and successfully simulated in 200x200x200 unit size. Microstructure evolution of single-phase and three-phase ceramic tool materials is simulated respectively. It can be found that the peak value of grain size distribution for three-phase nanoceramic tool material is smaller than average diameter. It indicates that the nanoparticles not only restrain grain boundary migration, but also prevent the elimination of small grains and refine matrix grains.


2004 ◽  
Vol 471-472 ◽  
pp. 369-373
Author(s):  
Sui Lian Wang ◽  
Li Qiang Xu ◽  
Chuan Zhen Huang ◽  
Han Lian Liu

Ti(C, N) based ceramic tool materials in the Ti (C0.7N0.3)-(Ni-Co)-Cr3C2-VC system have been made by hot-pressing technology, their mechanical properties and fracture morphologies have been studied under three different fabrication conditions. The results show that the mechanical properties are significantly influenced by fabrication conditions, and the main fracture mode is intergranular fracture.


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