Synthesis of AlN-SiC Ceramics by Hot Pressing

2013 ◽  
Vol 575-576 ◽  
pp. 166-169
Author(s):  
Li Juan Zhou ◽  
Yun Xia Zhao ◽  
Fan Tao Meng
Keyword(s):  
Hot Pressing ◽  
Lamellar Structure ◽  
Bending Strength ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sic Ceramics ◽  
Morphology Characteristics ◽  
Stoichiometric Proportion ◽  
Scanning Electron ◽  
Sintered Product

AlN-SiC ceramics were prepared at 1950°C by hot pressing (HP) of AlN/SiC powders in stoichiometric proportion. The sintered product was characterized using X-ray diffraction (XRD). Scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS) were utilized to investigate the morphology characteristics. The results show that AlN-SiC phase is well-developed with a close and lamellar structure. The grains are plate-like with the size of 1-3μm, the thickness of 3-5μm and elongated dimension. The results showed that the products had the density of 99 percent of the theoretical, bending strength of 550-800 MPa and fracture toughness of 5-6 MPa·m1/2. The distribution of AlN-SiC grains is relatively uniform.

Comparison of Mo-10Nb Alloy Target Materials Prepared by Different Techniques

2017 ◽  
Vol 726 ◽  
pp. 316-320 ◽  
Author(s):  
Jie Gao ◽  
You Jun Lu ◽  
Jun Feng Hou ◽  
Zhen Xia Yuan ◽  
Wen Luo ◽  
...  
Keyword(s):  
Hot Pressing ◽  
Element Distribution ◽  
Raw Material ◽  
Elemental Distribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alloy Target ◽  
Hot Pressing Sintering ◽  
Sintering Condition ◽  
Scanning Electron

The Mo powder and Nb powder was used as raw material, the Mo-10Nb alloy target was prepared by different sintering condition (non-pressure sintering and hot pressing sintering). The density, phase composition, microstructure and elemental distribution of Mo-10Nb alloy targets were determined by X-ray diffraction and scanning electron microscopy. The results showed that prepared by hot pressing Mo-10Nb alloy target density of 9.618 g/cm3, grain size 20 ~ 30μm, Mo and Nb element distribution.

scholarly journals Fabrication of Silk Resin with High Bending Properties by Hot-Pressing and Subsequent Hot-Rolling

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2716
Author(s):  
Hoang Anh Tuan ◽  
Shinji Hirai ◽  
Shota Inoue ◽  
Alharbi A. H. Mohammed ◽  
Shota Akioka ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Hot Pressing ◽  
Bending Strength ◽  
Decomposition Temperature ◽  
Attenuated Total Reflectance ◽  
X Ray Diffraction ◽  
Bending Properties ◽  
X Ray ◽  
Bombyx Mori Silk ◽  
Increased Strength

This research reports the processability and mechanical properties of silk resins prepared by hot-pressing followed by hot-rolling and then analyzes their thermal and structural properties. The results show that regenerated silk (RS) resins are better suited for hot-rolling than Eri and Bombyx mori silk resins (untreated silk). When hot-rolling at 160 °C with a 50% of reduction ratio, maximum bending strength and Young’s modulus of RS resin reaches 192 MPa and 10.2 GPa, respectively, after pretreatment by immersion in 40 vol% ethanol, and 229 MPa and 12.5 GPa, respectively, after pretreatment by immersion in boiling water. Increased strength of the material is attributed to the increased content of aggregated strands and intramolecular linking of β sheets (attenuated total reflectance Fourier-transform infrared spectroscopy) and higher crystallinity (X-ray diffraction analysis). After hot-pressing and hot-rolling, RS resins have a stable decomposition temperature (297 °C).

scholarly journals Standard Hot Pressing as a Possible Solution to Obtain Dense K0.5Na0.5NbO3 Ceramic Doped by Er2O3 and Yb2O3

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4171 ◽  
Author(s):  
Paweł Rutkowski ◽  
Jan Huebner ◽  
Adrian Graboś ◽  
Dariusz Kata ◽  
Dariusz Grzybek ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Rare Earth ◽  
Phase Composition ◽  
Powder Mixture ◽  
Hot Pressing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultrasonic Methods ◽  
Scanning Electron

In this study, the influence of the addition of rare earth oxides on the phase composition and density of KNN piezoelectric ceramics was investigated. The initial powders of Na2CO3 and K2CO3 were dried at 150 °C for 2 h. Then, a powder mixture for synthesis was prepared by adding a stoichiometric amount of Nb2O5 and 5 and 10 wt % overabundance of Na2CO3. All powders were mixed by ball-milling for 24 h and synthesized at 950 °C. The phase composition of the reaction bed was checked by means of X-ray diffraction (XRD). It had an appearance of tetragonal and monoclinic K0.5Na0.5NbO3 (KNN) phases. Then, 1 and 2 wt % of Er2O3 and Yb2O3, were added to the mixture. Green samples of 25 mm diameter and 3 mm thickness were prepared and sintered by hot pressing at 1000 °C for 2 h under 25 MPa pressure. The final samples were investigated via scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDS), XRD, Rietveld, and ultrasonic methods. Phase analysis showed tetragonal and orthorhombic KNN phases, and a contamination of (K2CO3·1.5H2O) was present. The obtained KNN polycrystals had a relative density above 95%. Texturing of the material was confirmed as a result of hot pressing.

Influence of Calcined CaSO4 Whisker and Dispersion Method on Bending Strength of Gypsum Board

2014 ◽  
Vol 638-640 ◽  
pp. 1350-1353
Author(s):  
Chang Chen ◽  
Yu Bin Wang ◽  
Wei Zhang ◽  
Xiao Yu Xue ◽  
Lei Liu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Aspect Ratio ◽  
Scanning Electron Microscope ◽  
Bending Strength ◽  
X Ray Diffraction ◽  
Hydration Time ◽  
Gypsum Board ◽  
Dispersion Method ◽  
X Ray ◽  
Scanning Electron

The hydration ability of CaSO4 whiskers calcined under the condition of 475-500 °C for 10-60 min was researched by X-ray diffraction and scanning electron microscope. The optimal calcined CaSO4 whiskers were added into building gypsum and the bending strength of gypsum board was influenced by different dispersion methods. The results show that the whiskers calcined under 475 °C for 30 min begin to hydrate and the aspect ratio of whisker calcined under 500 °C and 525 °C has no changed for 1 h of hydration time. The bending strength value of gypsum board with ultrasonic dispersed whisker is lower than that of gypsum board with directly mixed whisker.

Fabrication of TiAl/Ti2AlC Composite by Reaction Hot Pressing

2011 ◽  
Vol 52-54 ◽  
pp. 842-845 ◽  
Author(s):  
Jian Feng Zhu ◽  
Wen Wen Yang ◽  
Yi Ping Gong
Keyword(s):  
Electron Microscopy ◽  
Reaction Process ◽  
Hot Press ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Composite ◽  
The Matrix ◽  
Morphology Characteristics ◽  
Scanning Electron

TiAl/Ti2AlC in situ composite was successfully fabricated by hot-press-assisted reaction process from the mixture of Ti, Al and carbon black. The phase formation and transformation were investigated in detail by X-ray diffraction (XRD) and the morphology characteristics were also studied by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that when the mixed powders were hot pressed at 1300 °C for 1 h, full dense and highly pure TiAl/Ti2AlC composite was synthesized. The TiAl was the matrix phase and the in situ synthesized Ti2AlC was reinforcing phase. The reaction process was also discussed.

Fabrication and Mechanical Properties of SiC/Cu Composites with Zn Addition by Hot Pressing Sintering

2013 ◽  
Vol 745-746 ◽  
pp. 700-705
Author(s):  
Huang Liu ◽  
Guo Qiang Luo ◽  
Pin Gan Chen ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Mechanical Properties ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
High Volume ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zn Addition ◽  
Hot Pressing Sintering

SiC/Cu composites exhibit low density, low coefficient of thermal expansion and excellent mechanical properties. In this study, Zn of 2 wt. % was added as the sintering activator, and the high volume faction (60%) SiC/Cu composites was fabricated by hot pressing sintering technology. The phase composition and morphology of as-prepare samples were characterized by X-ray diffraction (XRD) system and scanning electron microscopy (SEM) equipped with an energy-dispersive spectroscopy (EDS) system. The as-prepared SiC/Cu composites were dense and uniform as well as void free. The results show that SiC/Cu composites can reach excellent mechanical properties of SiC/Cu composites. With the increase of sintering temperature, Vickers hardness and the bending strength of the samples increased obviously and the as-prepared SiC/Cu composites achieved a maximum Vickers hardness and bending strength respectively of 195MPa and 140MPa.

The Study of Theoretic Coated Carbon Amount and Excess Lithium in LiFePO4/C Synthesis by Means of Carbon Thermal Reduction Route

2013 ◽  
Vol 724-725 ◽  
pp. 1083-1086
Author(s):  
Ling Zhao ◽  
Wei Wang ◽  
Zheng Zhang ◽  
Xing Quan Liu
Keyword(s):  
Electron Microscope ◽  
Composite Cathode ◽  
Thermal Reduction ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
X Ray ◽  
Composite Cathode Material ◽  
Coated Carbon ◽  
Stoichiometric Proportion ◽  
Scanning Electron

LiFePO4/C(LFP/C) composite cathode material was synthesized by carbon thermal reduction route with the sucrose as reducing agent and characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Some parameters were optimized by means of determining the amount of sucrose and Li2CO3. The electrochemical performances were also tested through assembling batteries. The experimental results demonstrated that the proper theoretic coated carbon amount was 11.4% and 4.21% respectively, and the proper lithium usage is the normal stoichiometric proportion, namely, the lithium amount is not excess.

Fabrication and Characterization of a Feldspar-Alumina for Dental Ceramic

2010 ◽  
Vol 160-162 ◽  
pp. 424-427
Author(s):  
Guang Lei Zhang ◽  
Guo Qiang Qin ◽  
Yuan Hua Zhang ◽  
Pu Cheng ◽  
Chang Tao Shao
Keyword(s):  
Sinter Temperature ◽  
Bending Strength ◽  
Dental Ceramics ◽  
Alumina Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fabrication And Characterization ◽  
Sintering Method ◽  
Scanning Electron

Feldspar-alumina dental ceramics were produced by impressed sintering method and characterized by X-ray diffraction and scanning electron microscope techniques. The machinability of the obtained alumina ceramics was evaluated by grinding capacity in the simulative grinding experiment. The results show that an appropriate amount of feldspar additive can reduce the sinter temperature and improve density, bending strength and machinability of alumina dental ceramics. Under 10 wt% feldspar and 1450 °C sinter temperature, the relative density and bending strength of ceramic reached 93.62% and 235MPa, respectively.

scholarly journals Effect of Heat Treatment on the Microstructure and Phase Composition of ZrB2–MoSi2 Coating

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 779
Author(s):  
Marina Kovaleva ◽  
Igor Goncharov ◽  
Vseslav Novikov ◽  
Maxim Yapryntsev ◽  
Olga Vagina ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Lamellar Structure ◽  
Carbon Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mosi2 Coating ◽  
Α Al2o3 ◽  
Sprayed Coating ◽  
Scanning Electron

Composite ZrB2–MoSi2 coating modified by Y2O3 and Al was prepared by a new multi-chamber detonation accelerator (MCDS) on carbon/carbon composites. Postdeposition heat treatment of the samples at 1500 °C for 1 and 6 h was carried out in air. The effect of heat treatment on the microstructure and phase composition of the ZrB2–MoSi2 coating was investigated by scanning electron microscopy and X-ray diffraction phase analysis. The as-sprayed coating presented as a dense lamellar structure, composed of m-ZrO2, t-ZrO2, some hexagonal ZrB2, and cubic Al phases. The m-ZrO2, c-ZrO2, and h-(α-Al2O3) formed at 1500 °C. The coatings after heat treatment (1 and 6 h) exhibited a structure without cracks. The porosity (~1%) of the coating did not change after heat treatment. Thin, continuous, silica-rich film covered the surfaces of ZrO2 and Al2O3 particles, and could have played a role during heat treatment by acting as a grain lubricant for particle rearrangement.

Synthesis of CuIn0.7Ga0.3Se2 Nanoparticles and its Quarternary Sputtering Target

2013 ◽  
Vol 483 ◽  
pp. 65-70 ◽  
Author(s):  
Jun Zhou ◽  
Fu Qing Zhang ◽  
Li Hong Xia
Keyword(s):  
Hot Pressing ◽  
Rotation Speed ◽  
Mixing Time ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Sputtering Deposition ◽  
X Ray ◽  
Cigs Nanoparticles ◽  
Scanning Electron

The chalcopyrite-type of CuIn0.7Ga0.3Se2 nanoparticle was successfully prepared by mechanical alloying method (MA). The phase of the obtained powder was analyzed by x-ray diffraction (XRD), and its microstructure was analyzed by scanning electron microscope (SEM) and transmission election microscope (TEM). Subsequently, the sintering process of CIGS quarternary target was investigated. The result suggests that only CuIn0.7Ga0.3Se2 phase exist in the powder with the rotation speed of 350 r/min and 2 hours mixing time by planetary ball milling. The particles were seriously agglomerated and the size of agglomerates was about 100 nm. Finally the as-made CIGS nanoparticles were used to fabricate CIGS target through both pressureless sintering and hot pressing methods. The hot pressing was fairly effective to increase the density of CIGS target. This fabricated target can be used for magnetron-sputtering deposition of CIGS absorbers.

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