Pub Date : 2021-03-25DOI: 10.1080/17436753.2021.1904766
R. He, Qiaoling Zhang, Youzhi Liu, Jing Guo, Hongyan Shen
ABSTRACT In this study, the impinging stream-rotating packed bed and precipitation method were used to continuously prepare Fe and Co co-doped Titanium Dioxide by in-situ modification. With TiOSO4 solution containing Fe and Co2+ and NH3·H2O were sprayed on the packing and sheared by the packing that rotated at a high speed, resulting in improvement of microscopic mixing. The prepared catalyst is anatase with a particle size of 14 nm and a specific surface area of 194.34 m2/g. The photoresponse range is extended to 550 nm with a band gap of 2.5 eV. The photoluminescence results show that doping of Fe and Co can effectively inhibit the recombination of photogenerated electron-hole pairs. The percentage decomposition of 100 mg/L phenol under UV and visible light irradiation for 2.5 h is 88.71% and 24.58%, which is 1.59 and 2.07 times that for pure TiO2.
{"title":"Preparation of Fe and Co co-doped TiO2 by precipitation method in an impinging stream-rotating packed bed for photodegradation of phenol wastewater","authors":"R. He, Qiaoling Zhang, Youzhi Liu, Jing Guo, Hongyan Shen","doi":"10.1080/17436753.2021.1904766","DOIUrl":"https://doi.org/10.1080/17436753.2021.1904766","url":null,"abstract":"ABSTRACT In this study, the impinging stream-rotating packed bed and precipitation method were used to continuously prepare Fe and Co co-doped Titanium Dioxide by in-situ modification. With TiOSO4 solution containing Fe and Co2+ and NH3·H2O were sprayed on the packing and sheared by the packing that rotated at a high speed, resulting in improvement of microscopic mixing. The prepared catalyst is anatase with a particle size of 14 nm and a specific surface area of 194.34 m2/g. The photoresponse range is extended to 550 nm with a band gap of 2.5 eV. The photoluminescence results show that doping of Fe and Co can effectively inhibit the recombination of photogenerated electron-hole pairs. The percentage decomposition of 100 mg/L phenol under UV and visible light irradiation for 2.5 h is 88.71% and 24.58%, which is 1.59 and 2.07 times that for pure TiO2.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"96 1","pages":"134 - 143"},"PeriodicalIF":2.2,"publicationDate":"2021-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79004007","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 : 2021-02-17DOI: 10.1080/17436753.2021.1892363
Shuqi Guo
ABSTRACT In this study, the compositions 4TaC-1HfC and 1TaC-1HfC ceramics were prepared via hot pressing 5 vol.-% La2O3-doped TaC-HfC powder mixtures in temperature range of 1700–2000°C. The effect of sintering temperature on the densification of the two compositions was assessed. Highly dense TaC-HfC ceramics were obtained after hot pressing at sintering temperature of 1750°C or greater, depending on the composition. The elastic properties, electrical conductivity, hardness, fracture toughness and flexural strength of the resulting highly dense ceramics were evaluated. The results show that the elastic properties, hardness and fracture toughness were insensitive to the composition, but the electrical conductivity and room temperature strength. On the other hand, the strength of the two compositions substantially degraded as the temperature increased from room temperature to 1000°C and the degradation depended on the composition. Subsequently, the strength gradually decreased with further increasing temperature up to 1400°C, but this decrease was insensitive to the composition.
{"title":"Physical and mechanical behaviours of hot-pressed TaC–HfC ceramics with La2O3 additive","authors":"Shuqi Guo","doi":"10.1080/17436753.2021.1892363","DOIUrl":"https://doi.org/10.1080/17436753.2021.1892363","url":null,"abstract":"ABSTRACT In this study, the compositions 4TaC-1HfC and 1TaC-1HfC ceramics were prepared via hot pressing 5 vol.-% La2O3-doped TaC-HfC powder mixtures in temperature range of 1700–2000°C. The effect of sintering temperature on the densification of the two compositions was assessed. Highly dense TaC-HfC ceramics were obtained after hot pressing at sintering temperature of 1750°C or greater, depending on the composition. The elastic properties, electrical conductivity, hardness, fracture toughness and flexural strength of the resulting highly dense ceramics were evaluated. The results show that the elastic properties, hardness and fracture toughness were insensitive to the composition, but the electrical conductivity and room temperature strength. On the other hand, the strength of the two compositions substantially degraded as the temperature increased from room temperature to 1000°C and the degradation depended on the composition. Subsequently, the strength gradually decreased with further increasing temperature up to 1400°C, but this decrease was insensitive to the composition.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"25 1","pages":"117 - 126"},"PeriodicalIF":2.2,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83635260","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 The constitutive response of ceramics matrix composites (CMCs) under arbitrary loading and loading was studied. A method for determining the distribution of slip regions under arbitrary loading was proposed based on the shear lag model and slip law. Furthermore, a method for judging the closure of the matrix cracks was given based on the assumption that the fibre strain consists of the elastic strain and the pseudo-plastic strain of CMCsss. The stress–strain response of CMCs was obtained in form of matrices based on the distribution of the slip regions instead of the integration of fibre stress in each slip region. The simulated results show that the proposed method improves the computing efficiency greatly compared with previous approaches. Additionally, the simulated results agree well with experimental data, proving that the method proposed in this paper is credible.
{"title":"Prediction of stress–strain response of unidirectional ceramic matrix composites under arbitrary loading and unloading","authors":"Xiaodong Han, Xiguang Gao, Yingdong Song, Yuchun Feng","doi":"10.1080/17436753.2021.1882643","DOIUrl":"https://doi.org/10.1080/17436753.2021.1882643","url":null,"abstract":"ABSTRACT The constitutive response of ceramics matrix composites (CMCs) under arbitrary loading and loading was studied. A method for determining the distribution of slip regions under arbitrary loading was proposed based on the shear lag model and slip law. Furthermore, a method for judging the closure of the matrix cracks was given based on the assumption that the fibre strain consists of the elastic strain and the pseudo-plastic strain of CMCsss. The stress–strain response of CMCs was obtained in form of matrices based on the distribution of the slip regions instead of the integration of fibre stress in each slip region. The simulated results show that the proposed method improves the computing efficiency greatly compared with previous approaches. Additionally, the simulated results agree well with experimental data, proving that the method proposed in this paper is credible.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"39 8 1","pages":"84 - 94"},"PeriodicalIF":2.2,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76333710","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 : 2021-02-17DOI: 10.1080/17436753.2021.1889755
A. Abolhasani, F. Aslani, B. Samali, S. Ghaffar, H. Fallahnejad, S. Banihashemi
ABSTRACT In this paper, the effect of rice husk ash (RHA), as silicate impurities, on the microstructure and mechanical properties of calcium aluminate cement concrete (CACC) is explored. Various mechanical tests, including tests for obtaining the compressive, splitting tensile, flexural strengths and elastic modulus, were performed on different mixture designs containing different volume percentages of RHA (0, 2.5, 5, 7.5, and 10%) at W/Cs of 0.4 and 0.5. Furthermore, the impact of RHA on the microstructure of this concrete was examined through careful analysis of the scanning electron microscope (SEM) images and energy dispersive X-ray spectroscopy (EDS) results. The results demonstrate that, At W/C of 0.5, the microstructure and mechanical properties were improved, with the greatest improvement for the RHA substitution percentage of 5%. However, at W/C of 0.4, the addition of RHA showed no positive effect, which can be attributed to a higher specific surface area of RHA than cement.
{"title":"Silicate impurities incorporation in calcium aluminate cement concrete: mechanical and microstructural assessment","authors":"A. Abolhasani, F. Aslani, B. Samali, S. Ghaffar, H. Fallahnejad, S. Banihashemi","doi":"10.1080/17436753.2021.1889755","DOIUrl":"https://doi.org/10.1080/17436753.2021.1889755","url":null,"abstract":"ABSTRACT In this paper, the effect of rice husk ash (RHA), as silicate impurities, on the microstructure and mechanical properties of calcium aluminate cement concrete (CACC) is explored. Various mechanical tests, including tests for obtaining the compressive, splitting tensile, flexural strengths and elastic modulus, were performed on different mixture designs containing different volume percentages of RHA (0, 2.5, 5, 7.5, and 10%) at W/Cs of 0.4 and 0.5. Furthermore, the impact of RHA on the microstructure of this concrete was examined through careful analysis of the scanning electron microscope (SEM) images and energy dispersive X-ray spectroscopy (EDS) results. The results demonstrate that, At W/C of 0.5, the microstructure and mechanical properties were improved, with the greatest improvement for the RHA substitution percentage of 5%. However, at W/C of 0.4, the addition of RHA showed no positive effect, which can be attributed to a higher specific surface area of RHA than cement.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"9 2","pages":"104 - 116"},"PeriodicalIF":2.2,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17436753.2021.1889755","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72417890","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 : 2021-02-17DOI: 10.1080/17436753.2021.1889754
Sikai Ren, L. Gou
ABSTRACT An improvement in the thermoelectric properties of calcium cobaltite ceramics (Ca3Co4O9) was demonstrated through a modified co-precipitation method and lanthanum doping. With highly reactive precursors derived from the modified method, the energy consumption was conserved due to an apparent decrease in calcination duration. The conventional sintering produced a layer structure with the interconnected grains and the pores, which simultaneously optimised the thermal and electrical conductivity. The thermoelectric property was improved by the combination of the special morphology and ion substitution. The figure of merit ZT reached 0.205 (600°C) which was a competitive value for polycrystalline Ca3Co4O9 ceramics. The study provided a potential route for scalable production of Ca3Co4O9 ceramics with low energy use and excellent performance.
{"title":"Thermoelectric properties of the lanthanum-doped Ca3Co4O9 prepared by a modified parallel flow co-precipitation method","authors":"Sikai Ren, L. Gou","doi":"10.1080/17436753.2021.1889754","DOIUrl":"https://doi.org/10.1080/17436753.2021.1889754","url":null,"abstract":"ABSTRACT An improvement in the thermoelectric properties of calcium cobaltite ceramics (Ca3Co4O9) was demonstrated through a modified co-precipitation method and lanthanum doping. With highly reactive precursors derived from the modified method, the energy consumption was conserved due to an apparent decrease in calcination duration. The conventional sintering produced a layer structure with the interconnected grains and the pores, which simultaneously optimised the thermal and electrical conductivity. The thermoelectric property was improved by the combination of the special morphology and ion substitution. The figure of merit ZT reached 0.205 (600°C) which was a competitive value for polycrystalline Ca3Co4O9 ceramics. The study provided a potential route for scalable production of Ca3Co4O9 ceramics with low energy use and excellent performance.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"35 1","pages":"95 - 103"},"PeriodicalIF":2.2,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76298722","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 : 2021-02-17DOI: 10.1080/17436753.2021.1877596
L. R. Blackburn, D. Bailey, Shikuan Sun, L. J. Gardner, M. Stennett, C. Corkhill, N. Hyatt
ABSTRACT Zirconolite (CaZrTi2O7) has been identified as a candidate ceramic wasteform for the immobilisation and disposal of Pu inventories, for which there is no foreseen future use. Here, we provide an overview of relevant zirconolite solid solution chemistry with respect to Ce, U and Pu incorporation, alongside a summary of the available literature on zirconolite aqueous durability. The zirconolite phase may accommodate a wide variety of tri- and tetravalent actinide and rare-earth dopants through isovalent and heterovalent solid solution, e.g. CaZr1–x Pu x Ti2O7 or Ca1–x PuxZrTi2–2x Fe2x O7. The progressive incorporation of actinides within the zirconolite-2M parent structure is accommodated through the formation of zirconolite polytypoids, such as zirconolite-4M or 3T, depending on the choice of substitution regime and processing route. A variety of standardised durability tests have demonstrated that the zirconolite phase exhibits exceptional chemical durability, with release rates of constituent elements typically <10−5 gm−2·d−1. Further work is required to understand the extent to which polytype formation and surrogate choice influence the dissolution behaviour of zirconolite wasteforms.
{"title":"Review of zirconolite crystal chemistry and aqueous durability","authors":"L. R. Blackburn, D. Bailey, Shikuan Sun, L. J. Gardner, M. Stennett, C. Corkhill, N. Hyatt","doi":"10.1080/17436753.2021.1877596","DOIUrl":"https://doi.org/10.1080/17436753.2021.1877596","url":null,"abstract":"ABSTRACT Zirconolite (CaZrTi2O7) has been identified as a candidate ceramic wasteform for the immobilisation and disposal of Pu inventories, for which there is no foreseen future use. Here, we provide an overview of relevant zirconolite solid solution chemistry with respect to Ce, U and Pu incorporation, alongside a summary of the available literature on zirconolite aqueous durability. The zirconolite phase may accommodate a wide variety of tri- and tetravalent actinide and rare-earth dopants through isovalent and heterovalent solid solution, e.g. CaZr1–x Pu x Ti2O7 or Ca1–x PuxZrTi2–2x Fe2x O7. The progressive incorporation of actinides within the zirconolite-2M parent structure is accommodated through the formation of zirconolite polytypoids, such as zirconolite-4M or 3T, depending on the choice of substitution regime and processing route. A variety of standardised durability tests have demonstrated that the zirconolite phase exhibits exceptional chemical durability, with release rates of constituent elements typically <10−5 gm−2·d−1. Further work is required to understand the extent to which polytype formation and surrogate choice influence the dissolution behaviour of zirconolite wasteforms.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"74 1","pages":"69 - 83"},"PeriodicalIF":2.2,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80213508","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 : 2021-01-02DOI: 10.1080/17436753.2020.1840266
W. Dong, Shigen Zhu, B. Han, Bowen Fan, Ze Sun, Yilan Luo, Yunfeng Bai
ABSTRACT Fully dense WC-Al2O3 platelet composites with VC additive were fabricated by hot-press sintering. Their mechanical properties and microstructure were examined. The contents of Al2O3 platelet (Al2O3pl) and VC were optimised. The fracture toughness of WC-based composites would be obviously improved with Al2O3pl addition. The defined addition of VC was beneficial for the densification and improved mechanical properties of the WC-based composites. The microstructure of the composites was fine, compact and homogeneous compared with the composites without VC addition. The range of fracture toughness of WC-Al2O3pl composites was 9.3–13.5 MPa m1/2. The flexural strength of the composites varied a little and the maximum was 1289 MPa when the content of Al2O3pl was 5 vol.-%, the content of VC was 0.5wt-%.
{"title":"Effects of Al2O3 platelet and VC additive on sintering and mechanical properties of WC-based composites by hot pressing","authors":"W. Dong, Shigen Zhu, B. Han, Bowen Fan, Ze Sun, Yilan Luo, Yunfeng Bai","doi":"10.1080/17436753.2020.1840266","DOIUrl":"https://doi.org/10.1080/17436753.2020.1840266","url":null,"abstract":"ABSTRACT Fully dense WC-Al2O3 platelet composites with VC additive were fabricated by hot-press sintering. Their mechanical properties and microstructure were examined. The contents of Al2O3 platelet (Al2O3pl) and VC were optimised. The fracture toughness of WC-based composites would be obviously improved with Al2O3pl addition. The defined addition of VC was beneficial for the densification and improved mechanical properties of the WC-based composites. The microstructure of the composites was fine, compact and homogeneous compared with the composites without VC addition. The range of fracture toughness of WC-Al2O3pl composites was 9.3–13.5 MPa m1/2. The flexural strength of the composites varied a little and the maximum was 1289 MPa when the content of Al2O3pl was 5 vol.-%, the content of VC was 0.5wt-%.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"8 4 1","pages":"17 - 23"},"PeriodicalIF":2.2,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78226799","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 : 2020-12-23DOI: 10.1080/17436753.2020.1865094
V. Sharanraj, C. Ramesha, K. Kavya, Vasantha Kumar, M. Sadashiva, B. Chandan, M. Naveen Kumar
ABSTRACT Zirconia is a bioinert ceramic biomaterial. Zirconia having composition of 97% Zirconia oxide and 3% Yttria oxide finds its vital application in the field of dental ceramics as an implant material for having good inert characteristics like minimum interaction with the adjacent tissues and exhibits good aesthetic property. This paper presents the in-vitro tests conducted to evaluation toxicity by cell culturing on zirconia biomaterial used in the dental implant by both direct contact and extraction method. In the present study, in-vitro assessment of tissue biocompatibility was conducted on L929 cell line (mouse fibroblast). In-vitro test, the toxicity of Zirconia specimen was done by computing percentage of viability in a cell-cultured medium. An MTT system was used to measure the active cell activities with mitochondrial dehydrogenases, which is an easy method which gives accurate and precision results. The results of biocompatibility in-vitro test by both Direct and Extraction methods confirmed that Zirconia exhibits the highest cell growth of 93.17% and resulted with zero-grade cytotoxicity. Zirconia having good aesthetic characteristics, i.e. colour of the implant matches with the tooth colour. Hence Zirconia is a candidate implant material than other metal implants.
{"title":"Zirconia: as a biocompatible biomaterial used in dental implants","authors":"V. Sharanraj, C. Ramesha, K. Kavya, Vasantha Kumar, M. Sadashiva, B. Chandan, M. Naveen Kumar","doi":"10.1080/17436753.2020.1865094","DOIUrl":"https://doi.org/10.1080/17436753.2020.1865094","url":null,"abstract":"ABSTRACT Zirconia is a bioinert ceramic biomaterial. Zirconia having composition of 97% Zirconia oxide and 3% Yttria oxide finds its vital application in the field of dental ceramics as an implant material for having good inert characteristics like minimum interaction with the adjacent tissues and exhibits good aesthetic property. This paper presents the in-vitro tests conducted to evaluation toxicity by cell culturing on zirconia biomaterial used in the dental implant by both direct contact and extraction method. In the present study, in-vitro assessment of tissue biocompatibility was conducted on L929 cell line (mouse fibroblast). In-vitro test, the toxicity of Zirconia specimen was done by computing percentage of viability in a cell-cultured medium. An MTT system was used to measure the active cell activities with mitochondrial dehydrogenases, which is an easy method which gives accurate and precision results. The results of biocompatibility in-vitro test by both Direct and Extraction methods confirmed that Zirconia exhibits the highest cell growth of 93.17% and resulted with zero-grade cytotoxicity. Zirconia having good aesthetic characteristics, i.e. colour of the implant matches with the tooth colour. Hence Zirconia is a candidate implant material than other metal implants.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"279 1","pages":"63 - 68"},"PeriodicalIF":2.2,"publicationDate":"2020-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72687908","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 : 2020-12-15DOI: 10.1080/17436753.2020.1858010
D. Yu, Zuoxiang Zhu, Jianliang Min, C. Fang, D. Liao, N. Wu
ABSTRACT In order to improve the detection efficiency and image quality of Si3N4 ceramic bearing balls surface defects, digital image processing technology is used to analyse the information characteristics of Si3N4 ceramic bearing balls surface. A multi-scale decomposition enhancement algorithm for surface defect images of Si3N4 ceramic bearing balls based on the stationary wavelet transform is proposed. By building the surface defects detection system of Si3N4 ceramic bearing balls, the image enhancement program based on stationary wavelet transform with index low-pass filtering and nonlinear transform enhancement is designed. Finally, the effectiveness of the algorithm is verified by experiments. The experimental results show that the algorithm is applied to the surface defects image of Si3N4 ceramic bearing balls can effectively weaken the background noise and surface grinding texture, and enhance the contrast between defects and background clearly. In addition, the binary image is obtained by an adaptive threshold binary algorithm. After removing the tiny points by morphological opening operation, the defects are accurately and completely segmented, and then the Canny operator is used for edge detection to extract the edge contour of defects. When the decomposition level is set to 3, the average calculation time is 0.88 s, which are relatively short and have sufficient precision, and the algorithm can be extended to other kinds of ceramic ball surface damage detection.
{"title":"Multi-scale decomposition enhancement algorithm for surface defect images of Si3N4 ceramic bearing balls based on stationary wavelet transform","authors":"D. Yu, Zuoxiang Zhu, Jianliang Min, C. Fang, D. Liao, N. Wu","doi":"10.1080/17436753.2020.1858010","DOIUrl":"https://doi.org/10.1080/17436753.2020.1858010","url":null,"abstract":"ABSTRACT In order to improve the detection efficiency and image quality of Si3N4 ceramic bearing balls surface defects, digital image processing technology is used to analyse the information characteristics of Si3N4 ceramic bearing balls surface. A multi-scale decomposition enhancement algorithm for surface defect images of Si3N4 ceramic bearing balls based on the stationary wavelet transform is proposed. By building the surface defects detection system of Si3N4 ceramic bearing balls, the image enhancement program based on stationary wavelet transform with index low-pass filtering and nonlinear transform enhancement is designed. Finally, the effectiveness of the algorithm is verified by experiments. The experimental results show that the algorithm is applied to the surface defects image of Si3N4 ceramic bearing balls can effectively weaken the background noise and surface grinding texture, and enhance the contrast between defects and background clearly. In addition, the binary image is obtained by an adaptive threshold binary algorithm. After removing the tiny points by morphological opening operation, the defects are accurately and completely segmented, and then the Canny operator is used for edge detection to extract the edge contour of defects. When the decomposition level is set to 3, the average calculation time is 0.88 s, which are relatively short and have sufficient precision, and the algorithm can be extended to other kinds of ceramic ball surface damage detection.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"97 1","pages":"47 - 57"},"PeriodicalIF":2.2,"publicationDate":"2020-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75750127","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 : 2020-12-14DOI: 10.1080/17436753.2020.1858011
Shiya Ye, Duan Li, Liang Zeng, Jun-sheng Li, F. Cao
ABSTRACT Non-stoichiometric oxynitride with a composition of EuTaO1.75N1.25 was synthesized in <10 min through urea route combined with modified pressureless spark plasma sintering apparatus. The electronic properties of EuTaO1.75N1.25 was investigated by first-principles calculations. X-ray powder diffraction revealed that EuTaO1.75N1.25 crystallized with the cubic perovskite-type structure, S.G. , and a lattice constant of a = 4.0283(7) Å. Thermogravimetric studies revealed that EuTaO1.75 N1.25 decomposed at around 345 under the oxygen atmosphere, giving a final product of decomposition as EuTaO4 and Eu5Ta4O15 oxides. Magnetic susceptibility measurements indicated EuTaO1.75 N1.25's paramagnetic behavior with an estimated T c =9.9 K. The saturation moment of 6.82 μB which is smaller than 7 μB expected for Eu2+ can be due to the existence of Eu3+. The extremely low value obtained for remanence and coercive field agrees to the isotropic character of the 8S7/2 ground state associated to the Eu2+.
{"title":"Rapid synthesis, structure, and magnetic properties of the non-stoichiometric oxynitride EuTaO1.75N1.25","authors":"Shiya Ye, Duan Li, Liang Zeng, Jun-sheng Li, F. Cao","doi":"10.1080/17436753.2020.1858011","DOIUrl":"https://doi.org/10.1080/17436753.2020.1858011","url":null,"abstract":"ABSTRACT Non-stoichiometric oxynitride with a composition of EuTaO1.75N1.25 was synthesized in <10 min through urea route combined with modified pressureless spark plasma sintering apparatus. The electronic properties of EuTaO1.75N1.25 was investigated by first-principles calculations. X-ray powder diffraction revealed that EuTaO1.75N1.25 crystallized with the cubic perovskite-type structure, S.G. , and a lattice constant of a = 4.0283(7) Å. Thermogravimetric studies revealed that EuTaO1.75 N1.25 decomposed at around 345 under the oxygen atmosphere, giving a final product of decomposition as EuTaO4 and Eu5Ta4O15 oxides. Magnetic susceptibility measurements indicated EuTaO1.75 N1.25's paramagnetic behavior with an estimated T c =9.9 K. The saturation moment of 6.82 μB which is smaller than 7 μB expected for Eu2+ can be due to the existence of Eu3+. The extremely low value obtained for remanence and coercive field agrees to the isotropic character of the 8S7/2 ground state associated to the Eu2+.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"14 1","pages":"58 - 62"},"PeriodicalIF":2.2,"publicationDate":"2020-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81924935","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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