Hot-Press Sintering Densification, Microstructure and Properties of SiC-TiB2/B4C Composites

2014 ◽  
Vol 602-603 ◽  
pp. 488-493 ◽  
Author(s):  
Bao Xin Zhu ◽  
Yu Jun Zhang ◽  
Hong Sheng Wang ◽  
Chong Hai Wang ◽  
Shuang Shuang Yue

SiC-TiB2/B4C composites were fabricated by hot-press sintering B4C with silicon powder and tetrabutyl titanate (precursor of TiO2) as sintering and reinforcement agents. The influence of additives on hot-press sintering densification, microstructure and properties of composites were studied. The results showed that TiB2 and SiC generated by chemical reaction between additives and B4C matrix reinforced the sintering activity of the mixed powders and accelerated significantly the hot-press sintering densification rate of B4C from 1200 °C to 1700 °C. According to the SEM observation, the second phase of TiB2 and SiC particles synthetized in situ sited along the grain boundaries of B4C, meanwhile, those SiC particles of nanoscale size embedded into the B4C grains, and thereby, intra/inter-type ceramics formed. The maximum relative density of 98.1% was obtained with 9wt.% TiO2. The typical valus of Vickers hardness, bending strength and fracture toughness can reach 26.7 GPa, 580 MPa and 5.0 MPam1/2, respectively.

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 422
Author(s):  
Kuai Zhang ◽  
Yungang Li ◽  
Hongyan Yan ◽  
Chuang Wang ◽  
Hui Li ◽  
...  

An Fe/FeAl2O4 composite was prepared with Fe-Fe2O3-Al2O3 powder by a hot press sintering method. The mass ratio was 6:1:2, sintering pressure was 30 MPa, and holding time was 120 min. The raw materials for the powder particles were respectively 1 µm (Fe), 0.5 µm (Fe2O3), and 1 µm (Al2O3) in diameter. The effect of sintering temperature on the microstructure and mechanical properties of Fe/FeAl2O4 composite was studied. The results showed that Fe/FeAl2O4 composite was formed by in situ reaction at 1300 °C–1500 °C. With the increased sintering temperature, the microstructure and mechanical properties of the Fe/FeAl2O4 composite showed a change law that initially became better and then became worse. The best microstructure and optimal mechanical properties were obtained at 1400 °C. At this temperature, the grain size of Fe and FeAl2O4 phases in Fe/FeAl2O4 composite was uniform, the relative density was 96.7%, and the Vickers hardness and bending strength were 1.88 GPa and 280.0 MPa, respectively. The wettability between Fe and FeAl2O4 was enhanced with increased sintering temperature. And then the densification process was accelerated. Finally, the microstructure and mechanical properties of the Fe/FeAl2O4 composite were improved.


Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 204
Author(s):  
Kuai Zhang ◽  
Yungang Li ◽  
Chuang Wang ◽  
Hongyan Yan ◽  
Hui Li ◽  
...  

The Fe/FeAl2O4 cermet was prepared with Fe-Fe2O3-Al2O3 powder by a hot press sintering method at 1400 °C. The raw materials for the powder particles were respectively 2 µm (Fe), 0.5 µm (Fe2O3), and 0.5 µm (Al2O3) in diameter, the sintering pressure was 30 MPa, and the holding time was 120 min. The effects of different Fe mass ratios on the microstructure and mechanical properties of Fe/FeAl2O4 cermet were studied. The results showed that a new ceramic phase FeAl2O4 could be formed by an in situ reaction during the hot press sintering. When the Fe mass ratio was increased, the microstructure and mechanical properties of the Fe/FeAl2O4 cermet showed a change law that initially became better and then became worse. The best microstructure and mechanical properties were obtained in the S2 sample, where the mass ratio of Fe-Fe2O3-Al2O3 was 6:1:2. In this Fe mass ratio, the relative density was about 94%, and the Vickers hardness and bending strength were 1.21 GPa and 210.0 MPa, respectively. The reaction mechanism of Fe in the preparation process was the in situ synthesis reaction of FeAl2O4 and the diffusion reaction of Fe to FeAl2O4 grains. The increase of the Fe mass ratio improved the wettability of Fe and FeAl2O4, which increased the diffusion rate of Fe to FeAl2O4 grains, which increased the influence on the structure of FeAl2O4.


2014 ◽  
Vol 1030-1032 ◽  
pp. 103-107
Author(s):  
Li Li Tang ◽  
Ming Hu ◽  
Lin Shan ◽  
Yun Long Zhang

Electroless plating technology was applied in order to improve the poor wettability between the copper and SiC. SiCp/Cu composites were frbricated by hot-press sintering technique. The influences of SiC particles (Cu-coated and Cu-uncoated) and SiCp/Cu-5vol%n-SiC on microstructures, relative density, bending strength and coefficient of thermal expansion(CTE) were researched in detail. The results show that SiC particles distributed in Cu matrix uniformly. And a certain amount of SiC, the relative density and bending strength of SiCp/Cu(Cu-coated) composite were greater than SiCp/Cu(Cu-uncoated) composite, and the coefficient of thermal expansion was opposite, Between SiCp/Cu(Cu-coated) and SiCp/Cu-5vol% nanoscale SiC(n-SiC), the relative density and bending strength of SiCp/Cu(Cu-coated) were more than SiCp/Cu-5vol%n-SiC, and CTE was different.


2014 ◽  
Vol 1030-1032 ◽  
pp. 201-204
Author(s):  
Lin Shan ◽  
Ming Hu ◽  
Li Li Tang ◽  
Yun Long Zhang

In order to improve the interfacial wettability between Cu and β-SiC, electroless plating was employed to deposit a copper film on β-SiC particles. The β-SiC/Cu composites with different volume fraction ( from 30% to 60% ) were fabricated by hot-press sintering technique. The microstructures, bending strengths were investigated by SEM and a tensile machine. The results showed that the uniform and continuous Cu coating on the β-SiC particles can be obtained after electroless plating. With the increase of volume fraction of β-SiC particles, the bending strength decreased gradually. The fractographs revealed that the composites had mixed-fracture characteristics of cleavages and dimples.


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.


2007 ◽  
Vol 546-549 ◽  
pp. 2179-2182 ◽  
Author(s):  
Ling Bai ◽  
Xing Yu Zhao ◽  
Chang Chun Ge

Sintering of the Self-Propagating High-Temperature Synthesis (SHS) of β-Si3N4 powder with 6.67 wt.% Y2O3 and 3.33 wt.% Al2O3 as sintering additives has been emphatically investigated using hot-press sintering process. The relative density of hot-pressed β-Si3N4 reached near to the full densification (99.43%) at 1700°C. The similar micrographs with self-reinforcing rod-like β-Si3N4 grains forming an interlocking structure were observed. The better mechanical properties of hot-pressed Si3N4, such as the hardness (16.73GPa), fracture toughness (5.72 MPa·m1/2) and bending strength (611.72MPa) values, were obtained at 1700°C. The results indicate that good sinter ability can be obtained with the cheaply SHS of silicon nitride powder for preparing silicon nitride materials, which will make the cost of silicon nitride materials lowered.


2016 ◽  
Vol 697 ◽  
pp. 207-210
Author(s):  
Lian Meng Zhang ◽  
Yao Liu ◽  
Cheng Cheng Zhang ◽  
Guo Qiang Luo ◽  
Huang Liu ◽  
...  

Abstract. A new ternary composite of W-SiCP/Cu(40vol%) was designed and prepared by low-temperature hot-press sintering. The micro-structural characterizations were evaluated by X-ray diffraction (XRD) and scanning electron microstructure (SEM), coefficient of thermal expansion is measured. When sintered at 950°C-100MPa-2h, the relative density of the W-SiCP/Cu composites as a function of W content all exceeded 97%. Due to the plastic deformation of Cu, higher densification W-SiCP/Cu(40vol%) composites can be achieved at a relatively low temperature. The composites are characterized by the relatively low coefficient of thermal expansion, bending strength and hardness. The values of thermal expansion indicate that thermal expansion can be precisely controlled by adding SiC particles.


2012 ◽  
Vol 182-183 ◽  
pp. 328-331
Author(s):  
Yu Fang Yang ◽  
Kang Ju Li

The effect of particle size of iron and size of reinforce particle on properties of materials was studied systematically by the specimen current direct heating dynamic hot press sintering. It is found that mechanical properties of composites increase with the increasing particle size of iron. The properties of SiCp/Fe composites firstly increase and decrease with particle size of SiC and properties are better when size is 15μm.


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