Revealing dehydrogenation effect and resultant densification mechanism during pressureless sintering of TiH2 powder

2021 ◽  
Vol 873 ◽  
pp. 159792
Author(s):  
T. Chen ◽  
C. Yang ◽  
Z. Liu ◽  
H.W. Ma ◽  
L.M. Kang ◽  
...  
Keyword(s):  
Pressureless Sintering ◽  
Densification Mechanism ◽  
Tih2 Powder

Densification Mechanism of SnO2 Ceramics Doped with 5.0 mol% MnO2

2007 ◽  
Vol 351 ◽  
pp. 88-92 ◽  
Author(s):  
Guo Qiang Luo ◽  
J. Li ◽  
Dong Ming Zhang ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Grain Boundary ◽  
Oxygen Concentration ◽  
Manganese Oxides ◽  
Sintering Temperature ◽  
Heating Process ◽  
Pressureless Sintering ◽  
Cooling Process ◽  
Manganese Oxidation ◽  
Densification Mechanism ◽  
Different Temperatures

Dense SnO2 based ceramics are widely used. In this paper, 95SnO2-5MnO2 ceramics were prepared by pressureless sintering in air at different temperatures. Phase compositions and microstructures are examined by XRD, SEM and EDX, respectively. The SEM results show that different morphologies exist at the SnO2 grain boundary of ceramic, which compose of manganese oxidation, testified by EDX. The different manganese oxides phases, found by XRD, are the source of oxygen concentration at the grain boundary during heating and oxygen dissipation when cooling. However, solid solutions of Mn, Sn and O are not observed. The density of 95SnO2-5MnO2 ceramics decreases with increasing the sintering temperature, due to the evaporation of SnO and decreasing concentration of oxygen at grain boundary in the cooling process. Densification of the ceramic is promoted with inhibiting the decomposition of SnO2 by increasing oxygen concentration in the heating process, but it is limited by the dissipation of oxygen at the grain boundary in the cooling process.

Further experimental investigation on fast densification mechanism of bimodal powder during pressureless sintering of transparent AlON ceramics

2017 ◽  
Vol 43 (11) ◽  
pp. 8195-8201 ◽  
Author(s):  
Yingchun Shan ◽  
Zhaohui Zhang ◽  
Xiannian Sun ◽  
Jiujun Xu ◽  
Qinghua Qin ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Pressureless Sintering ◽  
Densification Mechanism

Fast densification mechanism of bimodal powder during pressureless sintering of transparent AlON ceramics

2016 ◽  
Vol 36 (3) ◽  
pp. 671-678 ◽  
Author(s):  
Yingchun Shan ◽  
Zhaohui Zhang ◽  
Xiannian Sun ◽  
Jiujun Xu ◽  
Qinghua Qin ◽  
...  
Keyword(s):  
Pressureless Sintering ◽  
Densification Mechanism

Densification and Thermal Conductivity of Y2O3-Doped AlN Ceramics by Spark Plasma Sintering

2007 ◽  
Vol 352 ◽  
pp. 227-231 ◽  
Author(s):  
Qiang Shen ◽  
Z.D. Wei ◽  
Mei Juan Li ◽  
Lian Meng Zhang
Keyword(s):  
Thermal Conductivity ◽  
Grain Boundaries ◽  
Spark Plasma Sintering ◽  
Particle Surface ◽  
Boundary Phase ◽  
Homogeneous Microstructure ◽  
Densification Mechanism ◽  
Sintering Additive ◽  
Plasma Sintering ◽  
Spark Plasma

AlN ceramics doped with yttrium oxide (Y2O3) as the sintering additive were prepared via the spark plasma sintering (SPS) technique. The sintering behaviors and densification mechanism were mainly investigated. The results showed that Y2O3 addition could promote the AlN densification. Y2O3-doped AlN samples could be densified at low temperatures of 1600-1700oC in 20-25 minutes. The AlN samples were characterized with homogeneous microstructure. The Y-Al-O compounds were created on the grain boundaries due to the reactions between Y2O3 and Al2O3 on AlN particle surface. With increasing the sintering temperature, AlN grains grew up, and the location of grain boundaries as well as the phase compositions changed. The Y/Al ratio in the aluminates increased, from Y3Al5O12 to YAlO3 and to Y4Al2O9. High-density, the growth of AlN grains and the homogenous dispersion of boundary phase were helpful to improve the thermal conductivity of AlN ceramics. The thermal conductivity of 122Wm-1K-1 for the 4.0 mass%Y2O3-doped AlN sample was reached.

scholarly journals Pressureless Sintering of YIG Ceramics from Coprecipitated Nanopowders

2021 ◽  
Vol 7 (5) ◽  
pp. 56
Author(s):  
Yimin Yang ◽  
Xiaoying Li ◽  
Ziyu Liu ◽  
Dianjun Hu ◽  
Xin Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Calcination Temperature ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Secondary Phase ◽  
Coprecipitation Method ◽  
Pressureless Sintering ◽  
Densification Behavior ◽  
Sintering Process

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.

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