Physical, Mechanical and Electrical Properties of W-20 wt.% Cu Composite Produced by Liquid Phase Sintering Process

2014 ◽  
Vol 879 ◽  
pp. 21-26
Author(s):  
Fauzi Ismail ◽  
Mohd Asri Selamat ◽  
Norhamidi Muhamad ◽  
Abu Bakar Sulong ◽  
Nurzirah Abdul Majid
Keyword(s):  
Particle Size ◽  
Liquid Phase ◽  
Electrical Properties ◽  
Microstructure Evolution ◽  
Sintering Temperature ◽  
Cold Isostatic Pressing ◽  
Liquid Phase Sintering ◽  
Sintering Process ◽  
Composite Powders ◽  
Mechanical And Electrical Properties

In this study, the effect of sintering temperature on the properties of tungsten-copper (W-Cu) composite produced by liquid phase sintering (LPS) process has been investigated. W-20 wt.% Cu composite powders with particle size less than 1 μm was prepared by cold compaction and followed by cold isostatic pressing. The green specimens were then sintered under nitrogen based atmosphere in the temperature range of 1100°C to 1300°C. The sintering studies were conducted to determine the extent of densification and corresponding to microstructure changes. In addition, the properties of the sintered specimens such as physical appearance, microstructure evolution, mechanical and electrical properties were presented and discussed.

scholarly journals Interpretation of Frenkel’s theory of sintering considering evolution of activated pores: I. Confirmation of the time constant

2014 ◽  
Vol 46 (2) ◽  
pp. 141-147 ◽  
Author(s):  
C.L. Yu ◽  
D.P. Gao ◽  
C.B. Xu ◽  
N.B. Tang ◽  
T. Zhao
Keyword(s):  
Particle Size ◽  
Liquid Phase ◽  
Theoretical Calculation ◽  
Time Constant ◽  
Liquid Phase Sintering ◽  
Sintering Process ◽  
Time Constants ◽  
Constant Determination ◽  
Cordierite Glass ◽  
Sintering Shrinkage

Frenkel?s theory of liquid-phase sintering was interpreted regarding pores as the activated component. The data of isothermal sintering shrinkage vs. time of the cordierite glass by Giess et al. are trained using the model by Nikolic et al. to obtain the relative density at varied temperatures and time. Then, the time constants are obtained as 1998.86mins, 388.21mins, 89.79mins and 26.11mins at 800?C, 820?C, 840?C and 860?C, respectively. The calculated time constants are close to that by the theoretical calculation, deviation of which arises from the fact that particle size is variable during the sintering process. The time constant determination is crucial to the research of the whole sintering process.

The Influence of AST Doping on the Dielectric Properties of MgTiO3-Based Ceramics Fabricated by Soild-State Sintering

2013 ◽  
Vol 634-638 ◽  
pp. 2378-2382
Author(s):  
Chun Yuan Luo ◽  
Jing Xiao Liu ◽  
Fei Shi ◽  
Ji Wei Wu ◽  
Chao Qian ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Liquid Phase ◽  
Dielectric Loss ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Sintering Process ◽  
Solid State Sintering ◽  
Doped Zno

AST-doped ZnO-MgTiO3-SrTiO3ceramics were prepared using a solid-state sintering process. The effects of AST (Al2O3-SiO2-TiO2) on the dielectric properties of MgTiO3-based ceramics were investigated. The results indicate that AST-doped MgTiO3-based ceramics could be obtained after 1205~1280°C sintering for 3 h. The XRD results indicate that the obtained MgTiO3-based ceramics contain high percentage of MgTi2O5 phase and the percentage increased with the increase of AST content. It was found that the occurred liquid-phase sintering by adding AST glass could effectively lower the sintering temperature and decrease the dielectric loss of MgTiO3-based ceramics. A minimum tanδ of 1.5×10-4 associated with εr=19.0 was achieved for 6.0 wt% AST-doped samples sintered at 1255°C.

Effect of Particle Size and Vacuum Sintering Temperature on Phase Composition and Mechanical Properties of WC-12 wt% Co Hardmetals

2012 ◽  
Vol 531-532 ◽  
pp. 3-7
Author(s):  
Shih Hsien Chang ◽  
Chung Wei Lee ◽  
Kuo Tsung Huang ◽  
Ming Wei Wu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Particle Size ◽  
Relative Density ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Sintering Process ◽  
Vacuum Sintering ◽  
Brittle Phase ◽  
Effect Of Particle Size

The experimental results indicated that the WC-12wt% Co specimens showed excellent mechanical properties and microstructure by the optimal sintering process. The G5 specimen sintered at 1400°C/1 h achieved a relative density of 98% and a hardness of HRA 88.5. Meanwhile, the TRS increased to 2400 MPa. F12 specimens that sintered at 1350°C/1 h achieved a relative density of 99% and a hardness of HRA 92.5. The TRS was also enhanced to 2170 MPa. In this study, the η phase (Co3W3C) precipitated at a high sintering temperature. The precipitations generated by liquid phase sintering gathered in some specific regions of the specimens and reacted with the WC particles. In addition, Co3W3C was a hard and brittle phase that resulted in a low TRS for the specimens; and a large amount of η phases were detrimental to the fracture toughness of the specimens.

scholarly journals Synthesis and Na+ Ion Conductivity of Stoichiometric Na3Zr2Si2PO12 by Liquid-Phase Sintering with NaPO3 Glass

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3790
Author(s):  
Yongzheng Ji ◽  
Tsuyoshi Honma ◽  
Takayuki Komatsu
Keyword(s):  
Solid State ◽  
Liquid Phase ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Ion Conductivity ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Sintering Time ◽  
Lower Activation

Sodium super ionic conductor (NASICON)-type Na3Zr2Si2PO12 (NZSP) with the advantages of the high ionic conductivity, stability and safety is one of the most famous solid-state electrolytes. NZSP, however, requires the high sintering temperature about 1200 °C and long sintering time in the conventional solid-state reaction (SSR) method. In this study, the liquid-phase sintering (LPS) method was applied to synthesize NZSP with the use of NaPO3 glass with a low glass transition temperature of 292 °C. The formation of NZSP was confirmed by X-ray diffraction analyses in the samples obtained by the LPS method for the mixture of Na2ZrSi2O7, ZrO2, and NaPO3 glass. The sample sintered at 1000 °C for 10 h exhibited a higher Na+ ion conductivity of 1.81 mS/cm at 100 °C and a lower activation energy of 0.18 eV compared with the samples prepared by the SSR method. It is proposed that a new LPE method is effective for the synthesis of NZSP and the NaPO3 glass has a great contribution to the Na+ diffusion at the grain boundaries.

Upconversion luminescence properties of Li+-doped ZnWO4:Yb,Er

2008 ◽  
Vol 23 (8) ◽  
pp. 2078-2083 ◽  
Author(s):  
Xi-xian Luo ◽  
Wang-he Cao
Keyword(s):  
Liquid Phase ◽  
Calcination Temperature ◽  
Crystal Field ◽  
Lower Energy ◽  
Upconversion Luminescence ◽  
Peak Position ◽  
Liquid Phase Sintering ◽  
Red Shift ◽  
Luminescence Properties ◽  
Sintering Process

Upconversion luminescence (UPL) characteristics and effects of Li+ ion on the UPL of ZnWO4:Yb,Er polycrystalline phosphors were investigated. It was shown that introduction of Li+ ions could reduce the calcination temperature by about 200 °C and increase the crystallinity of ZnWO4:Yb,Er by a liquid-phase sintering process via formation of Li2WO4 and other intermediates. UPL efficiency is remarkably promoted by Li+ ions. Moreover, the UPL spectrum of Li+-doped ZnWO4:Yb,Er presents a red shift, and the strongest peak position shifts from 553 to 559 nm. These can be attributed to a shift in the 4f level barycenter to lower energy, which results from lowering of the symmetry of the crystal field around Er3+.

SrTiO3 Based Dual-Functional Ceramics with Nano-Additives

2007 ◽  
Vol 336-338 ◽  
pp. 793-795 ◽  
Author(s):  
Hui Ming Ji ◽  
Xiao Chuan Liu ◽  
Ying Lv ◽  
Cui Xia Li ◽  
Xiao Dong Chen
Keyword(s):  
Electrical Properties ◽  
Nonlinear Coefficient ◽  
Liquid Phase Sintering ◽  
Composite Powders ◽  
Voltage Sensing ◽  
Reducing Atmosphere ◽  
Dual Functional ◽  
Donor And Acceptor ◽  
Nano Additives ◽  
Functional Ceramics

The electrical properties and microstructures of SrTiO3 based voltage-sensing and dielectric dual-functional ceramics with nanometer donor and acceptor additives were studied. The La2O3 nanopowders and MnO-SiO2-Al2O3 (or CuO-SiO2-Al2O3) nano-composite powders were incorporated into SrTiO3 as donor, acceptor and liquid-phase sintering aids. Then semiconducting SrTiO3-based ceramics were sintered at 1360-1440oC for 2 h in a reducing atmosphere. The effects of the nanometer donor and acceptor additives and the sintering temperature on the electrical properties and microstructures of materials were discussed. The results showed that SrTiO3-based varistor ceramics with 1.1 mol% La2O3 and 0.1 mol% MnO nano-additives sintered at 1360-1420oC in graphite and N2 reducing atmosphere have excellent voltage-sensing and dielectric characteristics. The varistor voltage ranges from 2.3 to 5.3 V/mm, the nonlinear coefficient from 3.0 to 3.8, and the dielectric constant from 215,600 to 413,000.

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