Xiaopeng Chang, Na Xu, Zhifeng Liu, Shuo Tian, Dekai Wen, Wanjiang Zheng, De-ming Wang
In this work g-C3N4/CuS composite film was prepared by successive ion layer adsorption and reaction (SILAR) method and used as the counter electrode in quantum dot sensitized solar cell (QDSSCs). To configure the cell, CdSe and CdS quantum dots acted as sensitizers on the photoanode side, polysulphide was used as the electrolyte and copper sulphide was deposited into the g-C3N4 film structure on the counter electrode side. Scanning electron microscope and X-ray diffraction were used to characterize the morphology and structure of the electrode materials, respectively. The photovoltaic performance of the cell was analysed by a standard solar simulator. The results revealed that the photoelectric conversion efficiency of the cell reached 3.65% under condition of AM 1.5 and irradiation intensity of 100mW/cm2.
{"title":"Preparation and performance of g-C3N4/CuS film as counter electrode for quantum dot sensitized solar cells","authors":"Xiaopeng Chang, Na Xu, Zhifeng Liu, Shuo Tian, Dekai Wen, Wanjiang Zheng, De-ming Wang","doi":"10.2298/pac2202167c","DOIUrl":"https://doi.org/10.2298/pac2202167c","url":null,"abstract":"In this work g-C3N4/CuS composite film was prepared by successive ion layer adsorption and reaction (SILAR) method and used as the counter electrode in quantum dot sensitized solar cell (QDSSCs). To configure the cell, CdSe and CdS quantum dots acted as sensitizers on the photoanode side, polysulphide was used as the electrolyte and copper sulphide was deposited into the g-C3N4 film structure on the counter electrode side. Scanning electron microscope and X-ray diffraction were used to characterize the morphology and structure of the electrode materials, respectively. The photovoltaic performance of the cell was analysed by a standard solar simulator. The results revealed that the photoelectric conversion efficiency of the cell reached 3.65% under condition of AM 1.5 and irradiation intensity of 100mW/cm2.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68580637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jesus de, S. Da, M. Ribeiro, S. Da, V. Arantes, A. Gomes
For the first time, alumina functionally graded materials (FGMs) with additions of niobium oxide, lithium fluoride and zirconia were produced by spark plasma sintering (SPS) and their sintering behaviour and dynamic properties were studied aiming to evaluate possibility of their use as ballistic shielding. Six groups of alumina samples with different layer compositions were produced by SPS at 1400 ?C/5min. The samples were characterized by dilatometry, scanning electron microscopy (SEM) and Hopkinson split bar method. The composition with the zirconia addition exhibited lower shrinkage rates at higher temperatures than the groups without zirconia, which promoted small sample shrinkage, resulting in lower density and higher porosity. The dynamic test showed that the alumina FGMs with layer containing LiF had the highest strain and strain rate values, exhibiting that the presence of continuous gradients in the composition positively affects the ceramic properties. Densification, layer change and cracks propagating through the material layers were also analysed by SEM analyses.
{"title":"Fabrication of Al2O3-Nb2O5-LiF-ZrO2 FGMs by SPS method: Microstructural evaluation, dynamic and sintering behaviour","authors":"Jesus de, S. Da, M. Ribeiro, S. Da, V. Arantes, A. Gomes","doi":"10.2298/pac2203251j","DOIUrl":"https://doi.org/10.2298/pac2203251j","url":null,"abstract":"For the first time, alumina functionally graded materials (FGMs) with additions of niobium oxide, lithium fluoride and zirconia were produced by spark plasma sintering (SPS) and their sintering behaviour and dynamic properties were studied aiming to evaluate possibility of their use as ballistic shielding. Six groups of alumina samples with different layer compositions were produced by SPS at 1400 ?C/5min. The samples were characterized by dilatometry, scanning electron microscopy (SEM) and Hopkinson split bar method. The composition with the zirconia addition exhibited lower shrinkage rates at higher temperatures than the groups without zirconia, which promoted small sample shrinkage, resulting in lower density and higher porosity. The dynamic test showed that the alumina FGMs with layer containing LiF had the highest strain and strain rate values, exhibiting that the presence of continuous gradients in the composition positively affects the ceramic properties. Densification, layer change and cracks propagating through the material layers were also analysed by SEM analyses.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68581394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-25DOI: 10.21203/rs.3.rs-827727/v1
V. Pavkov, G. Bakić, Vesna Maksimovic, I. Cvijović-Alagić, Marija Prekajski Đorđević, D. Bučevac, B. Matović
Modern industrial requirements include not only the usage of constructive materials with good mechanical properties but also materials obtained through environmentally friendly and low-cost processing procedures. Basalt, as a low-cost raw material, is regarded as a good candidate for industrial constructive parts production. In the present study, andesite basalt originated from the deposit site "Donje Jarinje", Serbia, was examined as a potential raw material for high-density ceramics production. The production of high-density ceramics included dry milling, homogenization, cold isostatic pressing, and sintering in the air. To determine the optimal processing parameters the sintering was conducted at 1040, 1050, 1060, 1070, and 1080 °C, and afterward the sintering duration was varied from 30 to 240 min at the optimal sintering temperature of 1060 °C. Characterization of the starting and sintered materials included the estimation of particle size distribution, density, hardness, and fracture toughness complemented with X-ray diffraction, light optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy analysis. Phase transformations did not occur during processing in the investigated temperature range from 1040 to 1080 °C. The obtained research results showed that 99.5% of relative density and the highest hardness and fracture toughness values of 6.7 GPa and 2.2 MPaÖm, respectively, were achieved for the andesite basalt sintered at 1060 °C for 60 min in the air. The results of the presented study confirmed that the sintered andesite basalt can be used as a high-density ceramic material for various industrial applications since this environmentally friendly material shows satisfactory mechanical properties.
{"title":"High-Density Ceramics Obtained By Andesite Basalt Sintering","authors":"V. Pavkov, G. Bakić, Vesna Maksimovic, I. Cvijović-Alagić, Marija Prekajski Đorđević, D. Bučevac, B. Matović","doi":"10.21203/rs.3.rs-827727/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-827727/v1","url":null,"abstract":"\u0000 Modern industrial requirements include not only the usage of constructive materials with good mechanical properties but also materials obtained through environmentally friendly and low-cost processing procedures. Basalt, as a low-cost raw material, is regarded as a good candidate for industrial constructive parts production. In the present study, andesite basalt originated from the deposit site \"Donje Jarinje\", Serbia, was examined as a potential raw material for high-density ceramics production. The production of high-density ceramics included dry milling, homogenization, cold isostatic pressing, and sintering in the air. To determine the optimal processing parameters the sintering was conducted at 1040, 1050, 1060, 1070, and 1080 °C, and afterward the sintering duration was varied from 30 to 240 min at the optimal sintering temperature of 1060 °C. Characterization of the starting and sintered materials included the estimation of particle size distribution, density, hardness, and fracture toughness complemented with X-ray diffraction, light optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy analysis. Phase transformations did not occur during processing in the investigated temperature range from 1040 to 1080 °C. The obtained research results showed that 99.5% of relative density and the highest hardness and fracture toughness values of 6.7 GPa and 2.2 MPaÖm, respectively, were achieved for the andesite basalt sintered at 1060 °C for 60 min in the air. The results of the presented study confirmed that the sintered andesite basalt can be used as a high-density ceramic material for various industrial applications since this environmentally friendly material shows satisfactory mechanical properties.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41337846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-12DOI: 10.1016/J.JEURCERAMSOC.2021.06.017
O. Chudinovych, O. Andrievskaya, J. D. Bogatyryova, V. V. Kovylyaev, O. Bykov
{"title":"Phase equilibria in the La2O3-Y2O3-Gd2O3 system at 1500°C","authors":"O. Chudinovych, O. Andrievskaya, J. D. Bogatyryova, V. V. Kovylyaev, O. Bykov","doi":"10.1016/J.JEURCERAMSOC.2021.06.017","DOIUrl":"https://doi.org/10.1016/J.JEURCERAMSOC.2021.06.017","url":null,"abstract":"","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/J.JEURCERAMSOC.2021.06.017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43791328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Can Wang, B. Fang, Shuai Zhang, Xiaolong Lu, Jianning Ding
To improve densification of the (Ba0.85Ca0.15)(Hf0.1Ti0.9)O3 (BCHT) ceramics prepared via powder injection moulding, MnO2 and Li2CO3 were used as sintering aids. The BCHT ceramics doped with different Mn- and Li-amount prepared by powder injection moulding in which paraffin was used as injection binder, have rather pure perovskite structure with complicated polymorphic ferroelectric phase coexistence. Polyhedral grains combined with nearly round shape grains with increased relative density and larger gains size were obtained at appropriate doping amount, related to the formation of liquid phase during sintering and increased mobility of ions due to the generation of point defects caused by heterovalent cations doping. TheMn- and Li-doped BCHT ceramics are displacement driven ferroelectrics with apparent diffused transition characteristic at different extent, relating to the morphotropic phase boundary composition and the variation of point defects induced by doping. Comparable or surpassing electrical performance was acquired, especially the dielectric breakdown strength was increased due to the improved sinterability. With appropriate doping amount, piezoelectricity larger than 300 pC/N can be obtained in the Mn- and Li-doped BCHT ceramics poled under low electric field.
{"title":"Doping effects in (Ba0.85Ca0.15)(Hf0.1Ti0.9)O3 lead-free piezoelectric ceramics prepared via powder injection moulding using simple binder","authors":"Can Wang, B. Fang, Shuai Zhang, Xiaolong Lu, Jianning Ding","doi":"10.2298/PAC2101047W","DOIUrl":"https://doi.org/10.2298/PAC2101047W","url":null,"abstract":"To improve densification of the (Ba0.85Ca0.15)(Hf0.1Ti0.9)O3 (BCHT) ceramics prepared via powder injection moulding, MnO2 and Li2CO3 were used as sintering aids. The BCHT ceramics doped with different Mn- and Li-amount prepared by powder injection moulding in which paraffin was used as injection binder, have rather pure perovskite structure with complicated polymorphic ferroelectric phase coexistence. Polyhedral grains combined with nearly round shape grains with increased relative density and larger gains size were obtained at appropriate doping amount, related to the formation of liquid phase during sintering and increased mobility of ions due to the generation of point defects caused by heterovalent cations doping. TheMn- and Li-doped BCHT ceramics are displacement driven ferroelectrics with apparent diffused transition characteristic at different extent, relating to the morphotropic phase boundary composition and the variation of point defects induced by doping. Comparable or surpassing electrical performance was acquired, especially the dielectric breakdown strength was increased due to the improved sinterability. With appropriate doping amount, piezoelectricity larger than 300 pC/N can be obtained in the Mn- and Li-doped BCHT ceramics poled under low electric field.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"15 1","pages":"47-57"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68578406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The microwave assisted combustion synthesis (MACS) as a new, quick and low cost synthesis method was used for preparation of niobium pentoxide (Nb2O5) powders. The present paper investigated the effect of reactant concentrations (ammonium niobium oxalate, urea and ammonium nitrate) on the characteristics of Nb2O5 nanoparticles. Three samples were synthesized with stoichiometric ratio between the fuel and oxidant (C1), excess of oxidant (C2) and excess of fuel (C3). In all samples, Nb2O5 crystalline nanoparticles with irregular morphology were detected. The synthesis of nanoparticles with smaller diameter in the C2 and C3 samples was confirmed by greater values of band gap energy measured through UV-Visible diffuse reflectance spectroscopy (indicating quantum confinement) and by the Rietveld refinement of X-ray diffraction patterns. The results showed that the amounts of oxidant and fuel can change synthesis temperature, influencing the final characteristics of the particles, such as size and existent phases. In these cases the excess of oxidant and fuel in the C2 and C3 samples, respectively, decreases the average synthesis temperature and decelerates the particle growth and the formation of the monoclinic phase.
{"title":"Nb2O5 nanoparticles obtained by microwave assisted combustion synthesis under different conditions","authors":"Thaís Luiz Marcial, F. Nakagomi, Reny Renzetti Angela, Guilherme Siqueira Oliveira","doi":"10.2298/pac2102128l","DOIUrl":"https://doi.org/10.2298/pac2102128l","url":null,"abstract":"The microwave assisted combustion synthesis (MACS) as a new, quick and low cost synthesis method was used for preparation of niobium pentoxide (Nb2O5) powders. The present paper investigated the effect of reactant concentrations (ammonium niobium oxalate, urea and ammonium nitrate) on the characteristics of Nb2O5 nanoparticles. Three samples were synthesized with stoichiometric ratio between the fuel and oxidant (C1), excess of oxidant (C2) and excess of fuel (C3). In all samples, Nb2O5 crystalline nanoparticles with irregular morphology were detected. The synthesis of nanoparticles with smaller diameter in the C2 and C3 samples was confirmed by greater values of band gap energy measured through UV-Visible diffuse reflectance spectroscopy (indicating quantum confinement) and by the Rietveld refinement of X-ray diffraction patterns. The results showed that the amounts of oxidant and fuel can change synthesis temperature, influencing the final characteristics of the particles, such as size and existent phases. In these cases the excess of oxidant and fuel in the C2 and C3 samples, respectively, decreases the average synthesis temperature and decelerates the particle growth and the formation of the monoclinic phase.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68578765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Ying, Cong Hu, Lu Liu, Cheng Sun, Dong Wen, Jianfeng Zhang, Yongting Zheng, Minghui Wang, Chen Zhang, Xiang Wang, Cheng Wang
High-purity and bulk Ta4AlC3 ceramics were successfully fabricated by spark plasma sintering (SPS) and subsequent heat treatment, using the raw materials including TaC and Ta2AlC powders. These raw materials were first synthesized by self-propagation high temperature synthesis from elements tantalum, aluminium and carbon black powders, followed by pressure-less sintering. The as-fabricated bulk Ta4AlC3 was relatively stable when subjected to heat treatment at elevated temperature of 1500?C. Moreover, prolonging the heat treatment time resulted in bigger grain sizes and higher densities of the Ta4AlC3. The flexural strength and the fracture toughness of the Ta4AlC3 fabricated by SPS were found to be 411MPa and 7.11MPa?m1/2, respectively. After the heat treatment at 1500?C for 8 h, the flexural strength and the fracture toughness of the Ta4AlC3 could reach 709MPa and 9.23MPa?m1/2, respectively. The special structural characteristics of the ternary ceramics and the increase of density after the heat treatment are the main reasons for the variation in mechanical properties of ternary ceramics.
{"title":"Mechanical properties of phase-pure bulk Ta4AlC3 prepared by spark plasma sintering and subsequent heat treatment","authors":"G. Ying, Cong Hu, Lu Liu, Cheng Sun, Dong Wen, Jianfeng Zhang, Yongting Zheng, Minghui Wang, Chen Zhang, Xiang Wang, Cheng Wang","doi":"10.2298/pac2103211y","DOIUrl":"https://doi.org/10.2298/pac2103211y","url":null,"abstract":"High-purity and bulk Ta4AlC3 ceramics were successfully fabricated by spark plasma sintering (SPS) and subsequent heat treatment, using the raw materials including TaC and Ta2AlC powders. These raw materials were first synthesized by self-propagation high temperature synthesis from elements tantalum, aluminium and carbon black powders, followed by pressure-less sintering. The as-fabricated bulk Ta4AlC3 was relatively stable when subjected to heat treatment at elevated temperature of 1500?C. Moreover, prolonging the heat treatment time resulted in bigger grain sizes and higher densities of the Ta4AlC3. The flexural strength and the fracture toughness of the Ta4AlC3 fabricated by SPS were found to be 411MPa and 7.11MPa?m1/2, respectively. After the heat treatment at 1500?C for 8 h, the flexural strength and the fracture toughness of the Ta4AlC3 could reach 709MPa and 9.23MPa?m1/2, respectively. The special structural characteristics of the ternary ceramics and the increase of density after the heat treatment are the main reasons for the variation in mechanical properties of ternary ceramics.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68579058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Si3N4 ceramic balls were prepared by gas pressure sintering with Y2O3 and Al2O3 as sintering additives. The effects of particle size of Y2O3-Al2O3 additives on densification, microstructure and mechanical properties of Si3N4 ceramic balls were investigated. The reliability of Si3N4 ceramic balls was evaluated through the Weibull modulus. The results showed that Si3N4 ceramic balls containing nanosized Y2O3-Al2O3 additives have a higher relative density and better comprehensivemechanical properties compared with the samples containing microsized additives, with relative density of 98.9 ? 0.2%TD, Vickers hardness of 14.7 ? 0.1GPa, indentation fracture toughness of 6.5 ? 0.1MPa?m1/2 and crushing strength of 254 ? 8.5MPa. The more homogeneous and extensive dispersion of the nanosized sintering additives in the Si3N4 matrix is the main reason for the enhancement in density and mechanical properties of the Si3N4 ceramic balls.
{"title":"Effect of particle size of Y2O3-Al2O3 additives on microstructure and mechanical properties of Si3N4 ceramic balls for bearing applications","authors":"Jing Zhang, Wenxue Wang, F. Sun, Weiru Zhang, Boheng Li, Ming-shuai Zhang","doi":"10.2298/pac2103297z","DOIUrl":"https://doi.org/10.2298/pac2103297z","url":null,"abstract":"Si3N4 ceramic balls were prepared by gas pressure sintering with Y2O3 and Al2O3 as sintering additives. The effects of particle size of Y2O3-Al2O3 additives on densification, microstructure and mechanical properties of Si3N4 ceramic balls were investigated. The reliability of Si3N4 ceramic balls was evaluated through the Weibull modulus. The results showed that Si3N4 ceramic balls containing nanosized Y2O3-Al2O3 additives have a higher relative density and better comprehensivemechanical properties compared with the samples containing microsized additives, with relative density of 98.9 ? 0.2%TD, Vickers hardness of 14.7 ? 0.1GPa, indentation fracture toughness of 6.5 ? 0.1MPa?m1/2 and crushing strength of 254 ? 8.5MPa. The more homogeneous and extensive dispersion of the nanosized sintering additives in the Si3N4 matrix is the main reason for the enhancement in density and mechanical properties of the Si3N4 ceramic balls.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68579527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Mohammadi, Y. B. Baba Ismail, K. Shariff, A. M. Mohd Noor
Akermanite (Ca2MgSi2O7) ceramic powders were prepared by a wet solid-state synthesis process using a mixture of oxide sources. The mechanism of phase formation included the formation of transition compounds such as diopside and merwinite. The compacted disks of the dried mixture were sintered at 1200, 1225 and 1250?C for different dwell times (2, 4 and 6 h). The effect of sintering temperature on the physical properties (relative density and diameter shrinkage), grain growth kinetics (grain growth activation energy) and mechanical properties (flexural strength) of the akermanite ceramics were evaluated. It was shown that the increase in sintering temperature from 1200 to 1250?C decreased the porosity and increased the diameter shrinkage and relative density of Ca2MgSi2O7 ceramics. The grain growth activation energy was also found to increase with the increase of sintering temperature. Finally, the increase in density yielded ceramics with high mechanical strength.
{"title":"Microstructure evolution, grain growth kinetics and mechanical properties of Ca2MgSi2O7 bioceramics sintered at various temperatures","authors":"H. Mohammadi, Y. B. Baba Ismail, K. Shariff, A. M. Mohd Noor","doi":"10.2298/pac2104357m","DOIUrl":"https://doi.org/10.2298/pac2104357m","url":null,"abstract":"Akermanite (Ca2MgSi2O7) ceramic powders were prepared by a wet solid-state synthesis process using a mixture of oxide sources. The mechanism of phase formation included the formation of transition compounds such as diopside and merwinite. The compacted disks of the dried mixture were sintered at 1200, 1225 and 1250?C for different dwell times (2, 4 and 6 h). The effect of sintering temperature on the physical properties (relative density and diameter shrinkage), grain growth kinetics (grain growth activation energy) and mechanical properties (flexural strength) of the akermanite ceramics were evaluated. It was shown that the increase in sintering temperature from 1200 to 1250?C decreased the porosity and increased the diameter shrinkage and relative density of Ca2MgSi2O7 ceramics. The grain growth activation energy was also found to increase with the increase of sintering temperature. Finally, the increase in density yielded ceramics with high mechanical strength.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68579718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the effects of sintering temperature on microstructure, dielectric and piezoelectric properties are investigated for the non-stoichiometric (Na0.48K0.473Li0.04Sr0.007)(Nb0.883Ta0.05Sb0.06Ti0.007)O3 (NKLNTSST) piezoelectric ceramics. The results suggest that the piezoelectric properties are enhanced owing to the more normal ferroelectric characteristics, higher density, more uniform grains and presence of polymorphic phase transition regions, which are observed with an increase in the sintering temperature up to 1080?C. The piezoelectric properties are weakened owing to the larger degree of diffuse phase transition and more cationoxygen-vacancy pairs with an increase in the sintering temperature above 1080?C. The best piezoelectric properties including kp = 40%, d33 = 288 pC/N, ?max = 72.12, loss = 2.57%, Ec = 13.45 kV/cm and Pr = 10.23 ?C/cm2 are obtained at the sintering temperature of 1080?C.
{"title":"Effects of sintering temperature on structure and electrical properties of (Na0.48k0.473Li0.04Sr0.007)(Nb0.883Ta0.05Sb0.06Ti0.007)O3 piezoelectric ceramics","authors":"Cheng‐Shong Hong, Yingfang Hong","doi":"10.2298/PAC2101079H","DOIUrl":"https://doi.org/10.2298/PAC2101079H","url":null,"abstract":"In this study, the effects of sintering temperature on microstructure, dielectric and piezoelectric properties are investigated for the non-stoichiometric (Na0.48K0.473Li0.04Sr0.007)(Nb0.883Ta0.05Sb0.06Ti0.007)O3 (NKLNTSST) piezoelectric ceramics. The results suggest that the piezoelectric properties are enhanced owing to the more normal ferroelectric characteristics, higher density, more uniform grains and presence of polymorphic phase transition regions, which are observed with an increase in the sintering temperature up to 1080?C. The piezoelectric properties are weakened owing to the larger degree of diffuse phase transition and more cationoxygen-vacancy pairs with an increase in the sintering temperature above 1080?C. The best piezoelectric properties including kp = 40%, d33 = 288 pC/N, ?max = 72.12, loss = 2.57%, Ec = 13.45 kV/cm and Pr = 10.23 ?C/cm2 are obtained at the sintering temperature of 1080?C.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"15 1","pages":"79-86"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68578674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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