scholarly journals Microstructure and Mechanical Properties of Spark Plasma Sintered Si3N4/WC Ceramic Tools

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1868 ◽  
Author(s):  
Zhenhua Wang ◽  
Jiheng Jia ◽  
Liyan Cao ◽  
Ning Sun ◽  
Yulin Wang

Silicon nitride (Si3N4) based ceramic tools exhibit good machinability in cutting materials such as gray cast iron, ductile iron, malleable cast iron, and superalloys due to excellent high-temperature mechanical properties. In this paper, high-performance Si3N4-based ceramic tools containing tungsten carbide (WC) and cobalt (Co) were studied. Effects of the WC content and Co content on mechanical properties and a microstructure of Si3N4-based ceramic materials were analyzed. Results showed that Si3N4-based ceramic material containing 10 wt % WC and 1 wt % Co had the best comprehensive mechanical properties at a sintering temperature of 1650 °C and holding time of 6 min, achieving Vickers hardness, fracture toughness, and room temperature bending strength of 16.96 GPa, 7.26 MPa·m1/2, and 1132 MPa, respectively. The microstructure of Si3N4-based ceramic tool material is uniform without obvious abnormal growth. The Si3N4-based ceramic tool was mainly composed of α-Si3N4, β-Si3N4, and WC phases.

2021 ◽  
Vol 47 (10) ◽  
pp. 14551-14560
Author(s):  
Shuai Zhang ◽  
Guangchun Xiao ◽  
Zhaoqiang Chen ◽  
Lianggang Ji ◽  
Chonghai Xu ◽  
...  

2013 ◽  
Vol 770 ◽  
pp. 308-311 ◽  
Author(s):  
Ming Dong Yi ◽  
Chong Hai Xu ◽  
Zhao Qiang Chen ◽  
Guang Yong Wu

A new nanomicro composite self-lubricating ceramic tool material was prepared with vacuum hot pressing technique. The effect of nanoAl2O3 powders on the microstructure and mechanical properties of nanomicro composite self-lubricating ceramic tool material was investigated. With the increase of nanoAl2O3 content, the hardness and fracture toughness first up then down. When the nanoAl2O3 content is 4 vol.%, the flexural strength, hardness and fracture toughness reaches 562 MPa, 8.46 MPa·m1/2 and 18.95 GPa, respectively. The microstructure and mechanical property of nanomicro composite self-lubricating ceramic tool material can be improved by the grain refinement strengthening of nanoAl2O3.


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.


2013 ◽  
Vol 589-590 ◽  
pp. 590-593 ◽  
Author(s):  
Min Wang ◽  
Jun Zhao

In order to investigate the effects of TiN content on Al2O3/TiN ceramic material (ATN), the ATN ceramic materials were prepared of TiN content in 30%, 40%, 50%, 60% in the condition of hot press sintering. The sintering temperature is 1700°C, the sintering press is 32MPa, and the holding time are 5min, 10min, 15min. The effects of TiN content on mechanical properties and microstructure of ATN ceramic materials were investigated by analyzing the bending strength, hardness, fracture toughness. The results show that ATN50 has the best mechanical property, its bending strength is 659.41MPa, vickers hardness is 13.79GPa, fracture toughness is 7.06MPa·m1/2. It is indicated that the TiN content has important effect on microstructure and mechanical properties of ATN ceramic materials.


2002 ◽  
Vol 34 (3) ◽  
pp. 223-229 ◽  
Author(s):  
O.I. Getman ◽  
V.V. Holoptsev ◽  
V.V. Panichkina ◽  
I.V. Plotnikov ◽  
V.K. Soolshenko

The mechanical properties and microstructure formation processes in Si3N4+3% AI2O3+5% Y2O3(Yb2O3) ceramic compacts sintered under microwave heating (MWH) and under traditional heating (TH) were investigated. The initial ceramic materials were powder blends of silicon nitride with oxides. The mean powder particle sizes were 0.5-1.0 mim. The content of alfa-phase in the Si3N4 powder was more than 95 %. The samples were sintered at 1800BC in nitrogen at normal pressure, the heating rate in all experiments was 60BC/min. The Vickers hardness (HV), fracture toughness (K1C) and bending strength (on) were determined. The microstructures of fracture surfaces of samples were studied by SEM. Quantitative microstructure analysis was carried out. It was shown that the values of HV and Kic of ceramic samples sintered under MWH at 1800BC rose steadily with the sintering time. This caused an increase in density, which reached maximum as fast as after 30 min of the MWH sintering; the mass loss at that time amounted to 3-4 %. The porosity of sintered samples with an addition of yttria was less than 1 %, that of ytterbia was greater, 2.4 %. For similar values of relative density, the hardness and fracture toughness of ceramic samples produced under MWH were higher as compared with those of samples sintered under TH. The microstructure of samples had the form of elongated grains in a matrix of polyhedral grains of the beta-Si3N4 phase. Measurements showed the mean size of grains in samples produced by MWH to be greater that in samples produced by TH. A larger number of elongated grains were formed. It was concluded that for sintering under MWH of Si3N4-based ceramics the growth of elongated beta-Si3N4 grains and formation of a "reinforced" microstructure were promoted and thereby improved the mechanical properties of such ceramics.


2016 ◽  
Vol 690 ◽  
pp. 150-155 ◽  
Author(s):  
Toyohiko Sugiyama ◽  
Keiji Kusumoto ◽  
Masayoshi Ohashi ◽  
Akinori Kamiya

The global warming is one of the most serious problems. The decrease of CO2 emissions in our daily life is an important subject today. Recently, an application of water retentive materials as a paving material has attracted a great deal of attention in Japan. This material is effective for reducing heat island phenomenon, which is also a recent problem in many cities in Japan. Water retained in the material during rainfall evaporates when heated by sunshine. The latent heat absorbed by evaporating water works to cool the surroundings. The water retentive ceramic products are expected to be useful for building materials as well as pavements. Several performances are required on the water retentive ceramics when it is used as building materials. Its cost and quality are the important factors. Porous ceramic materials formed by pressing without firing is one of ideal low cost and eco-friendly candidates. The porous ceramics is also expected to be produced from recycled ceramic materials. By optimizing its composition and forming method, a water retentive material with high performance was developed. The trial product had the properties as follows; fracture toughness: 1300N, bending strength: 175N/cm, water absorption: larger than 30%, and precision in size (length): +-0.5mm for 150mm. The product showed also enough frost resistance. In this paper, the fundamental properties of the porous ceramics prepared without firing are discussed with referring to the results of the field experiments.Another subject recently studied by several tile manufactures in Japan is the glazed tile with high solar reflectance. The exterior walls covered with such a high solar reflectance tile keeps the surface temperature of the wall lower under the strong sunshine of summer. It is effective against heat-island phenomenon. In this paper, the outline of the research results on visible and infrared reflectance of many kinds of glazes is also discussed.


2020 ◽  
Vol 46 (7) ◽  
pp. 8845-8852 ◽  
Author(s):  
Zhe Wang ◽  
Yue Liu ◽  
Bin Zou ◽  
Chuanzhen Huang ◽  
Kai Xue ◽  
...  

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