Pub Date : 2022-05-19DOI: 10.1080/17436753.2022.2121531
Meng Li, Zanlin Cheng, J. Dusza, Z. Song, Fangkun Xiao, Manfeng Gong, Shangyue Sun, Chengyu Zhang
ABSTRACT The wear behaviour of WC-Co cemented carbide reinforced with graphene platelets (WC-Co-GPLs composite) was investigated. The tribological parameters as friction coefficient and wear rate were measured using a ball-on-plate configuration with different contact loads. The microstructures and worn surfaces of composites were studied. The WC-Co-GPLs composite exhibits significantly better tribological properties in comparison to the WC-Co which is most evident at contact load of 80 N, where the friction coefficient and wear rate of the WC-Co-GPLs composite are 0.339 and 9.27 × 10−6 mm3·(m·N)−1, respectively. The improvement in wear behaviour of WC-Co-GPLs composite is attributed to the formation of the tribofilm during the wear test and enhancement of mechanical properties of the WC-Co-GPLs composite. The pulled-out GPLs attaches on the worn surface contribute to the formation of tribofilms during tribology test, especially at higher loads. The tribofilms protect the WC-Co-GPLs from wear and guarantee the integrity of the worn surface.
{"title":"Wear behaviour of graphene platelets reinforced WC-Co cemented carbide","authors":"Meng Li, Zanlin Cheng, J. Dusza, Z. Song, Fangkun Xiao, Manfeng Gong, Shangyue Sun, Chengyu Zhang","doi":"10.1080/17436753.2022.2121531","DOIUrl":"https://doi.org/10.1080/17436753.2022.2121531","url":null,"abstract":"ABSTRACT The wear behaviour of WC-Co cemented carbide reinforced with graphene platelets (WC-Co-GPLs composite) was investigated. The tribological parameters as friction coefficient and wear rate were measured using a ball-on-plate configuration with different contact loads. The microstructures and worn surfaces of composites were studied. The WC-Co-GPLs composite exhibits significantly better tribological properties in comparison to the WC-Co which is most evident at contact load of 80 N, where the friction coefficient and wear rate of the WC-Co-GPLs composite are 0.339 and 9.27 × 10−6 mm3·(m·N)−1, respectively. The improvement in wear behaviour of WC-Co-GPLs composite is attributed to the formation of the tribofilm during the wear test and enhancement of mechanical properties of the WC-Co-GPLs composite. The pulled-out GPLs attaches on the worn surface contribute to the formation of tribofilms during tribology test, especially at higher loads. The tribofilms protect the WC-Co-GPLs from wear and guarantee the integrity of the worn surface.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"17 1","pages":"143 - 149"},"PeriodicalIF":2.2,"publicationDate":"2022-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83491666","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 : 2022-04-03DOI: 10.1080/17436753.2022.2069988
K. Qian, Bingqing Li, T. Pu, Tianyi Bai, Yihong Liu
ABSTRACT The fitness of self-glazed zirconia (SGZ) onlays fabricated with computer-aided design/computer-aided manufacturing was analysed, and conventional impressions (CIs) were compared with intraoral digital impressions (DIs). Onlay preparation was applied on a typodont left mandibular first molar to create 22 copy dies, which were divided into DI and CI groups. The marginal gap of DI-fabricated onlays was smaller than that of CI-fabricated onlays (p < 0.05). In both groups, the marginal gap was larger in the distal gingival than in other regions (p < 0.05), and a trend of decreasing marginal accuracy after thermal cycling was observed. SGZ onlays performed well for internal fitness; the overall internal gaps were 72.05 ± 8.16 and 100.96 ± 22.53 μm in Groups DI and CI, respectively. SGZ onlays exhibited clinically acceptable marginal and internal fitness values. The marginal adaptation of DI-fabricated onlays was better than that of CI-fabricated onlays.
{"title":"Fitness of self-glazed zirconia onlays using conventional and digital impressions","authors":"K. Qian, Bingqing Li, T. Pu, Tianyi Bai, Yihong Liu","doi":"10.1080/17436753.2022.2069988","DOIUrl":"https://doi.org/10.1080/17436753.2022.2069988","url":null,"abstract":"ABSTRACT The fitness of self-glazed zirconia (SGZ) onlays fabricated with computer-aided design/computer-aided manufacturing was analysed, and conventional impressions (CIs) were compared with intraoral digital impressions (DIs). Onlay preparation was applied on a typodont left mandibular first molar to create 22 copy dies, which were divided into DI and CI groups. The marginal gap of DI-fabricated onlays was smaller than that of CI-fabricated onlays (p < 0.05). In both groups, the marginal gap was larger in the distal gingival than in other regions (p < 0.05), and a trend of decreasing marginal accuracy after thermal cycling was observed. SGZ onlays performed well for internal fitness; the overall internal gaps were 72.05 ± 8.16 and 100.96 ± 22.53 μm in Groups DI and CI, respectively. SGZ onlays exhibited clinically acceptable marginal and internal fitness values. The marginal adaptation of DI-fabricated onlays was better than that of CI-fabricated onlays.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"14 1","pages":"93 - 100"},"PeriodicalIF":2.2,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90655150","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 : 2022-04-03DOI: 10.1080/17436753.2022.2072676
Tauseef Ahmed, Mingyu Kim, S. Khan, Joonsik Lee, Sang-bok Lee, Hyo Tae Kim, Soonil Lee
ABSTRACT LaAlO3–BaSnO3 ceramics as a new microwave dielectric material were investigated in terms of optimum synthesis conditions and thereby the relative density, microstructure, solid-solution state, and dielectric properties with the addition of various sintering aids at different sintering temperatures. The dielectric properties of 0.9LaAlO3–0.1BaSnO3 (LA-0.1BS) were strongly influenced by relative density, microstructure, chemical ordering, and mixing rule of the dielectric constant. Densification of the LA-0.1BS ceramics was improved from 82.3 to 96.13% with an average grain size of around 1.9 µm at reduced sintering temperature by 250°C. The LA-0.1BS ceramics sintered with 3 mol% of Bi2O3–SiO2 (BS) showed dielectric constant (ϵr) ∼21.18 with associated dielectric loss (tan δ) ∼0.00824 and Q × f ∼1213.59 (10 GHz) which could be achieved at low sintering temperature of 1400–1450°C.
{"title":"Low temperature sintering and dielectric properties of LaAlO3–BaSnO3-based microwave dielectrics","authors":"Tauseef Ahmed, Mingyu Kim, S. Khan, Joonsik Lee, Sang-bok Lee, Hyo Tae Kim, Soonil Lee","doi":"10.1080/17436753.2022.2072676","DOIUrl":"https://doi.org/10.1080/17436753.2022.2072676","url":null,"abstract":"ABSTRACT LaAlO3–BaSnO3 ceramics as a new microwave dielectric material were investigated in terms of optimum synthesis conditions and thereby the relative density, microstructure, solid-solution state, and dielectric properties with the addition of various sintering aids at different sintering temperatures. The dielectric properties of 0.9LaAlO3–0.1BaSnO3 (LA-0.1BS) were strongly influenced by relative density, microstructure, chemical ordering, and mixing rule of the dielectric constant. Densification of the LA-0.1BS ceramics was improved from 82.3 to 96.13% with an average grain size of around 1.9 µm at reduced sintering temperature by 250°C. The LA-0.1BS ceramics sintered with 3 mol% of Bi2O3–SiO2 (BS) showed dielectric constant (ϵr) ∼21.18 with associated dielectric loss (tan δ) ∼0.00824 and Q × f ∼1213.59 (10 GHz) which could be achieved at low sintering temperature of 1400–1450°C.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"40 1","pages":"101 - 108"},"PeriodicalIF":2.2,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90946799","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 : 2022-04-03DOI: 10.1080/17436753.2022.2050665
Jooseong Kim, I. Bajpai, J. Jeon, Kyelim Yun, Jaeick Han, J. Shackelford, Young-Hwan Han, Sukyoung Kim
ABSTRACT The electric flash generated by an electric field aided the sintering of hydroxyapatite (HA) in relatively less time and at lower furnace temperatures than the conventional sintering method. The current work has reported a comparative study to explain thermodynamically the effects of the increasing DC electric field strength at 1000°C and 1100°C sintering furnace temperatures during flash sintering in terms of the grain growth and densification of the HA in air. The abrupt change in current density and conductivity of HA during the flash peak correlates the high grain growth and rapid densification with increasing electric field strength. The increased electric field strength reduced the power dissipation from the HA. The abrupt high-rise grain growth phenomenon during flash sintering might consist of the thermal effect and enhancement in ionic conductivity due to the application of an electric field.
{"title":"Abrupt high grain growth in hydroxyapatite during flash sintering","authors":"Jooseong Kim, I. Bajpai, J. Jeon, Kyelim Yun, Jaeick Han, J. Shackelford, Young-Hwan Han, Sukyoung Kim","doi":"10.1080/17436753.2022.2050665","DOIUrl":"https://doi.org/10.1080/17436753.2022.2050665","url":null,"abstract":"ABSTRACT\u0000 The electric flash generated by an electric field aided the sintering of hydroxyapatite (HA) in relatively less time and at lower furnace temperatures than the conventional sintering method. The current work has reported a comparative study to explain thermodynamically the effects of the increasing DC electric field strength at 1000°C and 1100°C sintering furnace temperatures during flash sintering in terms of the grain growth and densification of the HA in air. The abrupt change in current density and conductivity of HA during the flash peak correlates the high grain growth and rapid densification with increasing electric field strength. The increased electric field strength reduced the power dissipation from the HA. The abrupt high-rise grain growth phenomenon during flash sintering might consist of the thermal effect and enhancement in ionic conductivity due to the application of an electric field.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"8 1","pages":"87 - 92"},"PeriodicalIF":2.2,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73615924","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 : 2022-04-03DOI: 10.1080/17436753.2022.2086427
D. Mohanta, N. K. Mohanty, Khusboo Agrawal, B. Behera
ABSTRACT The composites, (1−x)(BiFe1-yLayO3)– xNaNbO3 with x = 0.25, 0.45 and y = 0.10, 0.20, are prepared by mixed oxide method. XRD analysis shows rhombohedral (hexagonal) structure at room temperature. The properties such as dielectric loss (tanδ) and dielectric constant (ϵr ) of all the samples are studied. A significant improvement in dielectric constants has been observed with the rise of Lanthanum (La) content. A dielectric anomaly above 350°C is observed for all the studied materials. Further, it is observed that ac conductivity (σ ac) spectrum obeys universal Jonscher’s power law. The variation of σ ac with inverse of temperature for all the samples is found to obey the Arrhenius equation. The formation of loop in polarisation verses electric field curve establishes the ferroelectric (FE) nature of all the studied samples. Current (I)-Electric Field (E) loops is studied to show the behaviour of domain switching.
{"title":"Electrical transport properties of La doped BiFeO3-NaNbO3 composite","authors":"D. Mohanta, N. K. Mohanty, Khusboo Agrawal, B. Behera","doi":"10.1080/17436753.2022.2086427","DOIUrl":"https://doi.org/10.1080/17436753.2022.2086427","url":null,"abstract":"ABSTRACT The composites, (1−x)(BiFe1-yLayO3)– xNaNbO3 with x = 0.25, 0.45 and y = 0.10, 0.20, are prepared by mixed oxide method. XRD analysis shows rhombohedral (hexagonal) structure at room temperature. The properties such as dielectric loss (tanδ) and dielectric constant (ϵr ) of all the samples are studied. A significant improvement in dielectric constants has been observed with the rise of Lanthanum (La) content. A dielectric anomaly above 350°C is observed for all the studied materials. Further, it is observed that ac conductivity (σ ac) spectrum obeys universal Jonscher’s power law. The variation of σ ac with inverse of temperature for all the samples is found to obey the Arrhenius equation. The formation of loop in polarisation verses electric field curve establishes the ferroelectric (FE) nature of all the studied samples. Current (I)-Electric Field (E) loops is studied to show the behaviour of domain switching.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"23 1","pages":"109 - 118"},"PeriodicalIF":2.2,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84703793","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}
ABSTRACT Sol–gel coating technology was applied to modify the bonding surface of self-glazed zirconia (SZ). Its effect on the bond strength of SZ to enamel was evaluated in vitro in comparison with the conventional milled zirconia treated by airborne-particle abrasion (CZa) and the heat-pressed lithium disilicate glass-ceramics treated by etching and silanization (LDe). All ceramic specimens were bonded to the etched bovine enamel with adhesive resin cement. Shear bond strength of both sol–gel coated SZ groups with different strategies (SZc1 and SZc2) was 20.00 ± 7.07 MPa and 18.32 ± 3.63 MPa, respectively, which was comparable to that of LDe, 18.44 ± 2.27 MPa (p > 0.05) and significantly higher than that of CZa, 11.72 ± 1.48 MPa, and SZ, 3.06 ± 1.66 MPa (p < 0.05). Lots of voids between zirconia clusters were observed on the bonding surface of SZc1, yet that of SZc2 showed homogeneous honeycomb nanoporous structure. All groups exhibited mixed failure except SZ, and the fracture surfaces of SZc1, SZc2, and LDe showed better wettability than CZa. Sol–gel coating could improve the bond strength of SZ to enamel, and the sol–gel coated SZ might have the potential to make minimally invasive restorations.
{"title":"Strengthen the bonding of self-glazed zirconia to enamel by sol–gel coating","authors":"Feifei Yu, Mingjie Wang, Lutong Song, Jing Zhao, Yuanna Zheng","doi":"10.1080/17436753.2022.2045165","DOIUrl":"https://doi.org/10.1080/17436753.2022.2045165","url":null,"abstract":"ABSTRACT Sol–gel coating technology was applied to modify the bonding surface of self-glazed zirconia (SZ). Its effect on the bond strength of SZ to enamel was evaluated in vitro in comparison with the conventional milled zirconia treated by airborne-particle abrasion (CZa) and the heat-pressed lithium disilicate glass-ceramics treated by etching and silanization (LDe). All ceramic specimens were bonded to the etched bovine enamel with adhesive resin cement. Shear bond strength of both sol–gel coated SZ groups with different strategies (SZc1 and SZc2) was 20.00 ± 7.07 MPa and 18.32 ± 3.63 MPa, respectively, which was comparable to that of LDe, 18.44 ± 2.27 MPa (p > 0.05) and significantly higher than that of CZa, 11.72 ± 1.48 MPa, and SZ, 3.06 ± 1.66 MPa (p < 0.05). Lots of voids between zirconia clusters were observed on the bonding surface of SZc1, yet that of SZc2 showed homogeneous honeycomb nanoporous structure. All groups exhibited mixed failure except SZ, and the fracture surfaces of SZc1, SZc2, and LDe showed better wettability than CZa. Sol–gel coating could improve the bond strength of SZ to enamel, and the sol–gel coated SZ might have the potential to make minimally invasive restorations.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"83 1","pages":"79 - 86"},"PeriodicalIF":2.2,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85509913","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 : 2022-02-17DOI: 10.1080/17436753.2022.2048624
M. Zhou, Yuzheng Wang, Laishi Li, Yusheng Wu, Hainan Li
ABSTRACT Foamed ceramic materials were prepared by shale residue and manganese slag as the primary raw materials, magnesium oxide as flux and silicon carbide as a foaming agent. The results show that the amount of shale residue has a significant effect on the physical properties of the foamed ceramics. The pore size of the foamed ceramics increases significantly with the increase of shale addition. By comparing A1, A2, A3 and A4, it is found that A2 is more suitable for producing foamed ceramics, with compressive strength of 14.20 Mpa, bulk density of 0.4425 g cm–3 and thermal conductivity of 0.1204 (w m–1k–1). The phase composition of foamed ceramics after sintering is mainly anorthite, galaxite and quartz.
以页岩渣和锰渣为主要原料,氧化镁为助熔剂,碳化硅为发泡剂制备泡沫陶瓷材料。结果表明,页岩渣的掺量对泡沫陶瓷的物理性能有显著影响。随着页岩添加量的增加,泡沫陶瓷的孔径明显增大。通过对比A1、A2、A3和A4,发现A2更适合制作泡沫陶瓷,抗压强度为14.20 Mpa,容重为0.4425 g cm-3,导热系数为0.1204 (w m-1k-1)。烧结后泡沫陶瓷的相组成主要为钙长石、星系石和石英。
{"title":"Preparation and physical properties of foamed ceramics from shale residue","authors":"M. Zhou, Yuzheng Wang, Laishi Li, Yusheng Wu, Hainan Li","doi":"10.1080/17436753.2022.2048624","DOIUrl":"https://doi.org/10.1080/17436753.2022.2048624","url":null,"abstract":"ABSTRACT Foamed ceramic materials were prepared by shale residue and manganese slag as the primary raw materials, magnesium oxide as flux and silicon carbide as a foaming agent. The results show that the amount of shale residue has a significant effect on the physical properties of the foamed ceramics. The pore size of the foamed ceramics increases significantly with the increase of shale addition. By comparing A1, A2, A3 and A4, it is found that A2 is more suitable for producing foamed ceramics, with compressive strength of 14.20 Mpa, bulk density of 0.4425 g cm–3 and thermal conductivity of 0.1204 (w m–1k–1). The phase composition of foamed ceramics after sintering is mainly anorthite, galaxite and quartz.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"21 1","pages":"52 - 56"},"PeriodicalIF":2.2,"publicationDate":"2022-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89823426","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 : 2022-01-05DOI: 10.1080/17436753.2021.2023804
Mangesh Lodhe, M. Balasubramanian
ABSTRACT The SiC nanowires were synthesised by the pyrolysis of a mixture of agricultural waste coconut shell (CS) and polycarbosilane (PCS) precursor at 1400°C. The characterisation of synthesised nanowires was carried out by X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. The single crystalline cubic β-SiC nanowires were found to be grown on <111> directions along (111) planes. The SiC nanowires had striped morphology containing stacking faults and twins as a planar defect. The extensive growth of SiC nanowires was owing to the continuous deposition of SiO and CO gaseous over the tiny SiC nuclei from the amorphous SiOC matrix. The vapour–solid (VS) and vapour–phase (VP) mechanisms have played the dominant role in nanowire formation. The 3C-SiC nanowires had striped morphology containing hexagonal 4H-SiC and 6H-SiC stacking faults.
{"title":"Polycarbosilane facilitated growth of SiC nanowires from biowaste coconut shell","authors":"Mangesh Lodhe, M. Balasubramanian","doi":"10.1080/17436753.2021.2023804","DOIUrl":"https://doi.org/10.1080/17436753.2021.2023804","url":null,"abstract":"ABSTRACT The SiC nanowires were synthesised by the pyrolysis of a mixture of agricultural waste coconut shell (CS) and polycarbosilane (PCS) precursor at 1400°C. The characterisation of synthesised nanowires was carried out by X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. The single crystalline cubic β-SiC nanowires were found to be grown on <111> directions along (111) planes. The SiC nanowires had striped morphology containing stacking faults and twins as a planar defect. The extensive growth of SiC nanowires was owing to the continuous deposition of SiO and CO gaseous over the tiny SiC nuclei from the amorphous SiOC matrix. The vapour–solid (VS) and vapour–phase (VP) mechanisms have played the dominant role in nanowire formation. The 3C-SiC nanowires had striped morphology containing hexagonal 4H-SiC and 6H-SiC stacking faults.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"77 1","pages":"39 - 45"},"PeriodicalIF":2.2,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83926679","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 : 2022-01-02DOI: 10.1080/17436753.2022.2031666
Gokul Nanda, Nithin Chandran, Ganesh Babu Thiyagarajan, R. Devasia, Ravi Kumar
ABSTRACT In this work, a Zr–La–B–C(O)-based precursor-derived ceramic system is spark plasma sintered at 1600°C for 10 min. Chemical and phase analysis of the sintered ceramic reveals nanocrystalline ultra-high temperature (UHT) phases of ZrB2, ZrC, and La2Zr2O7 embedded in a glassy carbon matrix. A comprehensive evaluation of mechanical properties and thermal expansion characteristics correlates well with the presence of phases. Depth-sensing nanoindentation exemplifies high elastic recovery of 91% typically seen in glassy carbons. The hardness and Young’s modulus measured to be ∼4.5 and ∼29.5 GPa respectively, seem to be governed mainly by the presence of glassy carbon, and secondarily by stiff B–C bonds and the UHT phases. The linear coefficient of thermal expansion measured from 130°C to 1550°C is ∼7.9 × 10−6 K−1 and the thermal expansion behaviour is found to be strongly driven by the constituent UHT phases.
{"title":"Mechanical response and thermal expansion characteristics of spark plasma sintered Zr–La–B–C(O)-based precursor-derived ceramics","authors":"Gokul Nanda, Nithin Chandran, Ganesh Babu Thiyagarajan, R. Devasia, Ravi Kumar","doi":"10.1080/17436753.2022.2031666","DOIUrl":"https://doi.org/10.1080/17436753.2022.2031666","url":null,"abstract":"ABSTRACT In this work, a Zr–La–B–C(O)-based precursor-derived ceramic system is spark plasma sintered at 1600°C for 10 min. Chemical and phase analysis of the sintered ceramic reveals nanocrystalline ultra-high temperature (UHT) phases of ZrB2, ZrC, and La2Zr2O7 embedded in a glassy carbon matrix. A comprehensive evaluation of mechanical properties and thermal expansion characteristics correlates well with the presence of phases. Depth-sensing nanoindentation exemplifies high elastic recovery of 91% typically seen in glassy carbons. The hardness and Young’s modulus measured to be ∼4.5 and ∼29.5 GPa respectively, seem to be governed mainly by the presence of glassy carbon, and secondarily by stiff B–C bonds and the UHT phases. The linear coefficient of thermal expansion measured from 130°C to 1550°C is ∼7.9 × 10−6 K−1 and the thermal expansion behaviour is found to be strongly driven by the constituent UHT phases.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"1 1","pages":"31 - 38"},"PeriodicalIF":2.2,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72884699","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 : 2021-12-28DOI: 10.1080/17436753.2021.2014276
Chin Sheng Chua, Sean Yong Ow, S. L. Liew, Junyi Liu, C. B. Soh, L. Shen, Shijie Wang
ABSTRACT This paper reports the 3D printing of fibre-reinforced ceramic composite with hierarchical structures. Through printing precursor formulation, short SiC fibres have been successfully incorporated into silicate materials and gradient porous hierarchical structure has been achieved for the printed parts. The mechanical testing shows a 27% improvement in impact strength, 22% improvement in flexural modulus, and 7.5% in flexural strength compared with parts without fibre reinforcement. High-resolution tomography analysis using x-ray microscopy shows that the inner structure has a porosity of 27%, while the outer layer shows a dense structure with little pores formation. This 3D printed ceramic composite with fibre-reinforcement shows high similarity to the gradient porous structures of human bone and tooth. The results indicate that 3D printing of nano/microfibre reinforced ceramic composite with hierarchical structure is a promising method to enhance the fracture toughness of ceramics and allow accurate patient-specific customisation for their implants.
{"title":"3D printing of fibre-reinforced ceramic composites with hierarchical structure","authors":"Chin Sheng Chua, Sean Yong Ow, S. L. Liew, Junyi Liu, C. B. Soh, L. Shen, Shijie Wang","doi":"10.1080/17436753.2021.2014276","DOIUrl":"https://doi.org/10.1080/17436753.2021.2014276","url":null,"abstract":"ABSTRACT This paper reports the 3D printing of fibre-reinforced ceramic composite with hierarchical structures. Through printing precursor formulation, short SiC fibres have been successfully incorporated into silicate materials and gradient porous hierarchical structure has been achieved for the printed parts. The mechanical testing shows a 27% improvement in impact strength, 22% improvement in flexural modulus, and 7.5% in flexural strength compared with parts without fibre reinforcement. High-resolution tomography analysis using x-ray microscopy shows that the inner structure has a porosity of 27%, while the outer layer shows a dense structure with little pores formation. This 3D printed ceramic composite with fibre-reinforcement shows high similarity to the gradient porous structures of human bone and tooth. The results indicate that 3D printing of nano/microfibre reinforced ceramic composite with hierarchical structure is a promising method to enhance the fracture toughness of ceramics and allow accurate patient-specific customisation for their implants.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"32 1","pages":"46 - 51"},"PeriodicalIF":2.2,"publicationDate":"2021-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73286869","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}