检索结果-南通市图书馆

Hot pressing sintering process and sintering mechanism of W-La_(2)O_(3)-Y_(2)O_(3)-ZrO_(2)

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2021年第7期40卷 1949-1956页

作者： Bao-Gang Fu Jian-Can Yang Zhi-Kun Gao Zuo-Ren Nie College of Materials Science and Engineering Beijing University of TechnologyBeijing 100124China

The W-La_(2)O_(3)-Y_(2)O_(3)-ZrO_(2)materials were prepared by vacuum hot pressing sintering *** microstructure was characterized by scanning electron microscopy(SEM).The effects of sintering temperature,sintering pressure,holding time and heating rate on relative density,hardness and microstructure were *** sintering activation energy of the powder was *** on the result,the best sintering parameters by vacuum hot pressing sintering are as follows:sintering temperature of 1600℃,sintering pressure of 60 MPa and holding time of 60 *** heating rate is 10℃·min^(-1)from room temperature to 1000℃and 4℃·min^(-1)from1000 to 1600℃.Using this process,the grain size is about3 lm in diameter with relative density at 99.7%,and the hardness is HV *** sintering characteristic index(n)of the specimen is 4,and the sintering mechanism mainly depends on the diffusion from the surface to the intragranular in the volume *** sintering activation energy of W-La_(2)O_(3)-Y_(2)O_(3)-ZrO_(2)material is286.2 k J·mol^(-1),which indicates that the powder has higher activity in sintering process.

关键词： W-La_(2)O_(3)-Y_(2)O_(3)-ZrO_(2) Hot pressing sintering Relative density Tungsten electrode sintering mechanism

The Influences of Controlling sintering mechanism on Electrical Properties of Multilayer PTCR Chip

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2015年第4期30卷 674-678页

作者：黄汉华陈勇李璋 YANG Huai YANG Zhao GUO Jiacheng YANG Yan Faculty of Physics and Electronic Technology Hubei University Engineering Research Center of Nano-Geo Materials of Ministry of Education China University of Geosciences

Experiments were designed to investigate the influence of controlling sintering mechanism on electrical properties of multilayer PTCR chip. During the preparation process, heating rate, sintering temperature, high-temperature holding time and cooling method were respectively regulated to prepare multilayer PTCR chip with good performance. After the process of organic casting, the casting PTCR green films were sintered at 1 260-1 280 ~C for 0.5 h at reduction atmosphere, which was heated at the rate of 400 ℃/h. Then selecting 300 ℃/h as the cooling rate, the ceramics were oxidated at 850 ℃ for 1 h. The prepared multilayer PTCR chips exhibited room temperature resistivity of below 100 Ω.cm, and resistance rising rate more than 104 unit through the Curie temperature.

关键词： PTCR sintering mechanism multilayer BaTiO3

Study on the sintering mechanism of Tin Oxide Ceramics Doping with Pr2O3

在线全文

学校读者我要写书评

暂无评论

Study on the Sintering Mechanism of Tin Oxide Ceramics Dopin...

In situ investigation on densification mechanism of Ti-20Al-19Nb(at.%)alloy by TiH_(2)-assisted pressureless sintering

中国材料大会2012

作者： Qingwei Wang Hongzhi Wang Wei Ning Lida Luo Engineering Research Center of Advanced Glasses Manufacturing Technology MOE Donghua University College of Material Science & Engineering of Donghua University

ISBN: (纸本)9783037856079

The Pr2O3 doped SnO2 dense ceramic was prepared by co-precipitation method and further sintering. Through the micrograph of the cross-sectional microstructure of the electrodes, the sintering process was analyzed and discussed. Results showed that the solid phase sintering was exhibited at the early stage;when sintering was kept going on, the instant liquid phase could be emerged due to the rich dopants in the grain boundary. Finally, there would be much secondary phase existe as the concentration of dopants reached to a certain value.

关键词： sintering mechanism Ceramics Tin Oxide Rare earth Secondary phase.

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第34期165卷 170-186页

作者： Qi Cai Qilin Yu Xinyao Li Yao Lu Yanmo Li Ganggang Cui School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Welding Engineering and Laser Processing Centre Cranfield UniversityBedfordshireMK43 OALUK Luoyang Ship Material Research Institute Luoyang 471023China

Dense Ti-20Al-19Nb(at.%)alloys can be cost-effectively fabricated by TiH_(2)-assisted pressureless sintering;nevertheless,the densification mechanism remains controversial without understanding the entire sintering *** in situ observing the surface morphology of the Ti/Al/Nb and Ti/TiH_(2)/Al/Nb compacts upon heating,the densification mechanism of the Ti-20Al-19Nb alloys was elucidated in this *** addition to the reported reason that the dehydrogenation of TiH_(2)provided reactive Ti,the densification of Ti-20Al-19Nb alloy was found to be strongly associated with the phase transformations upon *** TiH_(2)participated in the reverse eutectoid transformation,α-Ti+δ-TiH_(2)→β-Ti,inducing theα/βand TiH_(2)/βgrain boundaries for the rapid diffusion of *** reaction of Ti(s)+Al(s)→TiAl_(3)(s)was then accelerated,and the majority of the Al phase was consumed in the solid state,which significantly reduced the pores from the transient liquid *** activation energy of the Ti-Al reaction decreased with the addition of TiH_(2),and the growth mode of the TiAl_(3)phase was *** removing the large pores at 700℃,the Ti-Al intermetallic phases were well connected,forming the continuous interdiffusion route for Ti,Al,and *** diffusion of Nb,as well as the phase transformation ofα2→B2,was then promoted,and the ripening time for the B2 phase was *** a result,the density and mechanical properties were *** initial results of this study provided a foundation for the cost-effective fabrication of high-strength Ti-Al alloys containing refractory elements.

关键词： Ti-Al-Nb alloy sintering mechanism Porosity In situ observation Phase transformation

Densification mechanism of stereolithographical dense Si_(3)N_(4) ceramics with CeO_(2) as sintering additive by field assisted sintering

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Central South University 2021年第4期28卷 1233-1243页

作者： RAO Wei-dong LIU Yao CHENG Li-jing LIU Shao-jun State Key Laboratory for Powder Metallurgy Central South UniversityChangsha 410083China Shenzhen Research Institute Central South UniversityShenzhen 518007China College of Mechanical and Electronic Engineering Pingxiang UniversityPingxiang 337000China School of Mechanical Engineering Hebei University of TechnologyTianjin 300130China

Combining sintering additive with field assisted sintering,stereolithographical dense Si3N4 ceramics was successfully *** to a large amount of polymer during the stereolithography,the green parts have the characteristics of low powder loading and high *** the process parameters such as sintering temperature and soaking time can effectively improve the density of the *** stress exponent n of all specimens is in a range of 1 and 2,which is derived from a modified sintering kinetics *** apparent activation energy Qd of stereolithographic Si_(3)N_(4) ceramics sintered with applied pressures of 30 MPa,40 MPa,and 50 MPa is 384.75,276.61 and 193.95 kJ/mol,respectively,suggesting that the densification dynamic process is strengthened by raising applied *** grain boundary slipping plays a dominating role in the densification of stereolithographic Si3N4 *** Vickers hardness and fracture toughness of stereolithographic Si3N4 ceramics are HV10/10(1347.9±2.4)and(6.57±0.07)MPaAbstract:Combining sintering additive with field assisted sintering,stereolithographical dense Si3N4 ceramics was successfully *** to a large amount of polymer during the stereolithography,the green parts have the characteristics of low powder loading and high *** the process parameters such as sintering temperature and soaking time can effectively improve the density of the *** stress exponent n of all specimens is in a range of 1 and 2,which is derived from a modified sintering kinetics *** apparent activation energy Qd of stereolithographic Si3N4 ceramics sintered with applied pressures of 30 MPa,40 MPa,and 50 MPa is 384.75,276.61 and 193.95 kJ/mol,respectively,suggesting that the densification dynamic process is strengthened by raising applied *** grain boundary slipping plays a dominating role in the densification of stereolithographic Si3N4 *** Vickers hardness and fracture toughn

关键词： stereolithography silicon nitride ceramics sintering mechanism densification field assisted sintering

Preparation of Superfine-Cemented Carbide by Spark Plasma sintering

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2006年第1期21卷 42-45页

作者：解迎芳王兴庆 School of Materials Science and Engineering Shanghai University Shanghai 200072 China

92WC-8Co puwder mixture with superfine-tungsten carbide was respectively sintered by spark plasma sintering（ SPS ） and sintering isostutic pressure （SIP）. Complete dense samples with 200 nm WC grains and 94.2HRA hardness were prepared by spark plasma sintering at 1 150 ℃ and under 4.5 kN for 5 minutes. SIP was carried out at 1 400 ℃ for 30 minutes with a result of 300-400 nm WC grains and 93 HRA hardness. The results show that sintering temperature is greatly decreased by SPS, sintering time is largely shortened and WC grain growth is effectively retarded. Micropores and drawb（wks in superfine-cemented carbide made by SPS are greatly declined, which is very useful to improving nwehanical properties.

关键词： spurk plasma sintering cemented carbide superfine grain sintering mechanism

mechanism of conductive powder microstructure evolution in the process of SPS

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2005年第3期48卷 258-269页

作者： SONG Xiaoyan LIU Xuemei ZHANG Jiuxing College of Materials Science and Engineering Key Laboratory of Advanced Functional Materials of Ministry of Education of ChinaBeijing University of TechnologyBeijing 100022China

Spark plasma sintering(SPS)is an advanced sintering technology that has been recently developed in the *** to many reports about experimental investigations on the methods of new materials preparation,there are very few systematic studies on the special sintering mechanism of SPS *** the present paper,by using the pure electrolytic copper powders as the raw material,a series of sintering experiments have been designed and carried *** evolution of the powder microstructures during SPS has been systematically studied,and for the first time a“self-adjusting mechanism”of the microstructure evolution is proposed,from which the essential for the advantages of materials preparation by SPS in the respects of high density,homogeneity and fine grain structure can be well *** addition,the changes of the relative density during SPS are quantitatively predicted by a theoretical model and confirmed by the experimental measurements.

关键词： spark plasma sintering microstructure evolution sintering mechanism

Effects of SPS Pulse Current on Interface of Al90Mn9Ce1/ZrO2 Micro-cellular Structure Composites

在线全文

学校读者我要写书评

暂无评论

Effects of SPS Pulse Current on Interface of Al90Mn9Ce1/ZrO2...