Pub Date : 2023-07-03DOI: 10.1590/1980-5373-mr-2022-0625
Mário V. Medeiros Filho, L. O. D. Silva, M. S. Libório, J. Queiroz, K. S. Coan, L. S. Rossino, T. Costa, R. Sousa
AISI 6160 steel is used to manufacture cutting blades and springs due to its high tensile strength and good ductility. However, it has low mechanical strength and low wear resistance. In this work, a duplex treatment consisting of CCPD followed by PN was performed to improve the surface properties of the steel. In addition, XRD, optical microscopy, microhardness, and sphere-disk tribological analysis were used to verify the surface changes of the samples. The results showed a significant improvement in surface hardness and better wear resistance of AISI 6160 Steel submitted to Duplex treatment. The sample submitted to the CCPD treatment for 4 hours and, after nitriding at 500 °C for 2 hours, presented higher surface hardness and wear resistance than the sample only subjected to plasma deposition, characterizing the efficiency of the use of the duplex treatment adopted in the present work.
{"title":"Film Deposition by Duplex Treatment with Hastelloy Cage on AISI 6160 Steel","authors":"Mário V. Medeiros Filho, L. O. D. Silva, M. S. Libório, J. Queiroz, K. S. Coan, L. S. Rossino, T. Costa, R. Sousa","doi":"10.1590/1980-5373-mr-2022-0625","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0625","url":null,"abstract":"AISI 6160 steel is used to manufacture cutting blades and springs due to its high tensile strength and good ductility. However, it has low mechanical strength and low wear resistance. In this work, a duplex treatment consisting of CCPD followed by PN was performed to improve the surface properties of the steel. In addition, XRD, optical microscopy, microhardness, and sphere-disk tribological analysis were used to verify the surface changes of the samples. The results showed a significant improvement in surface hardness and better wear resistance of AISI 6160 Steel submitted to Duplex treatment. The sample submitted to the CCPD treatment for 4 hours and, after nitriding at 500 °C for 2 hours, presented higher surface hardness and wear resistance than the sample only subjected to plasma deposition, characterizing the efficiency of the use of the duplex treatment adopted in the present work.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67304080","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 : 2023-07-03DOI: 10.1590/1980-5373-mr-2022-0477
C. Hernández-Vásquez, M. Albor-Aguilera, J. Flores-Marquez, M. Gonzalez-Trujillo
The polycrystalline CdS/CdTe thin film solar cell is one of the most important photovoltaic devices for cost-effective generation of solar electricity for terrestrial applications. A typical superstrate structure of CdTe solar cell has been studied through current-voltage (J-V) and secondary ion mass spectroscopy (SIMS) measurements. A close correlation between quality of interphases and its photovoltaic efficiency was determined. It was found an improvement of open circuit voltage (V OC ) and efficiency associated to CdS and CdTe thermal treatments, and a reduction of diffusion of S and Cd into CdTe and CdS respectively. An efficiency of 12% has been reached on solar cells with a Te and ZnTe interlayer as part of the back contact. Low diffusion of Cu along absorbent material was observed when Te and ZnTe was used creating a stable back contact along the time. Diffusion and intermixing at each junction SnO 2 :F/CdS, CdS/CdTe and CdTe/Te or ZnTe/Cu/Au was found, establishing limit values of element diffusion along CdTe solar cells.
{"title":"Intermixing and Diffusion Impact on CdS/CdTe/p+ Regions (Te or ZnTe)/Cu/Au Solar Cell Interphases","authors":"C. Hernández-Vásquez, M. Albor-Aguilera, J. Flores-Marquez, M. Gonzalez-Trujillo","doi":"10.1590/1980-5373-mr-2022-0477","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0477","url":null,"abstract":"The polycrystalline CdS/CdTe thin film solar cell is one of the most important photovoltaic devices for cost-effective generation of solar electricity for terrestrial applications. A typical superstrate structure of CdTe solar cell has been studied through current-voltage (J-V) and secondary ion mass spectroscopy (SIMS) measurements. A close correlation between quality of interphases and its photovoltaic efficiency was determined. It was found an improvement of open circuit voltage (V OC ) and efficiency associated to CdS and CdTe thermal treatments, and a reduction of diffusion of S and Cd into CdTe and CdS respectively. An efficiency of 12% has been reached on solar cells with a Te and ZnTe interlayer as part of the back contact. Low diffusion of Cu along absorbent material was observed when Te and ZnTe was used creating a stable back contact along the time. Diffusion and intermixing at each junction SnO 2 :F/CdS, CdS/CdTe and CdTe/Te or ZnTe/Cu/Au was found, establishing limit values of element diffusion along CdTe solar cells.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67303165","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 : 2023-06-30DOI: 10.1590/1980-5373-mr-2022-0466
M. Horta, Cecília Westin, D. N. Rocha, J. B. Campos, Rodrigo F. M. Souza, M. Aguilar, F. J. Moura
The use of biogenic residues to obtain calcium phosphate compounds, mainly hydroxyapatite (HAp)
利用生物残留物获得磷酸钙化合物，主要是羟基磷灰石(HAp)
{"title":"Hydroxyapatite from biowaste for biomedical applications: obtainment, characterization and in vitro assays","authors":"M. Horta, Cecília Westin, D. N. Rocha, J. B. Campos, Rodrigo F. M. Souza, M. Aguilar, F. J. Moura","doi":"10.1590/1980-5373-mr-2022-0466","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0466","url":null,"abstract":"The use of biogenic residues to obtain calcium phosphate compounds, mainly hydroxyapatite (HAp)","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"125 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67302973","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 : 2023-06-30DOI: 10.1590/1980-5373-mr-2022-0453
M. Ferreira, J. Nascimento, N. Leite, A. Siervo, G. L. Fernandes, A. Vaz, R. V. Gelamo, I. Aoki, J. Moreto
The aerospace industry is constantly looking for innovative materials that exhibit good mechanical and corrosion properties. The 2198-T851 (Al-Cu-Li) alloy was developed to replace the conventional Al-Cu-Mg in aircraft structures. Despite the usefulness of the 2198-T851 alloy, its performance may be affected when subjected to an aggressive medium containing chloride ions. The deposition of Nb 2 O 5 coatings by using the reactive sputtering technique on the 2198-T851 alloy surface appears as a powerful tool to improve the corrosion resistance of this material. Recently, groundbreaking research findings have demonstrated the positive effect of Nb 2 O 5 coatings on corrosion protection of alloy 2198-T851. However, the corrosion products originated from the 2198-T851 aluminium alloy are poorly understood. The use of Raman spectroscopy and XPS techniques may help to shed some light on the corrosion products of 2198-T851 alloy. Results demonstrated the corrosion products are mainly composed by CuCl 2 x H 2 O, CuCl, Cu 2 Cl(OH) 3 , Al(OH) 3 , and AlO(OH).
{"title":"The Potentialities of Raman and XPS Techniques to Evaluate the Corrosion Products Formed on the 2198-T851 Aluminium Alloy Exposed to Sodium Chloride Solution","authors":"M. Ferreira, J. Nascimento, N. Leite, A. Siervo, G. L. Fernandes, A. Vaz, R. V. Gelamo, I. Aoki, J. Moreto","doi":"10.1590/1980-5373-mr-2022-0453","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0453","url":null,"abstract":"The aerospace industry is constantly looking for innovative materials that exhibit good mechanical and corrosion properties. The 2198-T851 (Al-Cu-Li) alloy was developed to replace the conventional Al-Cu-Mg in aircraft structures. Despite the usefulness of the 2198-T851 alloy, its performance may be affected when subjected to an aggressive medium containing chloride ions. The deposition of Nb 2 O 5 coatings by using the reactive sputtering technique on the 2198-T851 alloy surface appears as a powerful tool to improve the corrosion resistance of this material. Recently, groundbreaking research findings have demonstrated the positive effect of Nb 2 O 5 coatings on corrosion protection of alloy 2198-T851. However, the corrosion products originated from the 2198-T851 aluminium alloy are poorly understood. The use of Raman spectroscopy and XPS techniques may help to shed some light on the corrosion products of 2198-T851 alloy. Results demonstrated the corrosion products are mainly composed by CuCl 2 x H 2 O, CuCl, Cu 2 Cl(OH) 3 , Al(OH) 3 , and AlO(OH).","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67302963","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 : 2023-06-30DOI: 10.1590/1980-5373-mr-2022-0500
M. Moretti, J. Sagás, A.A.C. Recco
Thin films of titanium aluminum nitride (Ti (1-x) Al x N) were deposited on silicon, copper, and plasma nitrided AISI D2 tool steel substrates through reactive direct current grid-assisted magnetron sputtering. The depositions were performed in the metal and compound modes using nitrogen flow rates of (7.2 ± 0.1) sccm and (6.8 ± 0.2) sccm, respectively. The relations between the process parameters and the crystallographic orientation were investigated. Chemical and mechanical properties were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and instrumented indentation technique (IIT). X-ray diffraction spectra and electron diffraction patterns revealed the presence of a Ti (1-x) Al x N phase with a face-centered cubic structure in both films. In metal mode, the coatings exhibited a preferential (111) plane orientation, changing to (200) in the compound mode. The change in preferential orientation was influenced by the reactive gas partial pressure.
通过无功直流栅辅助磁控溅射，在硅、铜和等离子体氮化AISI D2工具钢基体上沉积了氮化钛铝薄膜(Ti (1-x) Al x N)。在氮气流量为(7.2±0.1)sccm和(6.8±0.2)sccm的情况下，在金属和化合物模式下进行沉积。研究了工艺参数与结晶取向的关系。采用x射线光电子能谱(XPS)、x射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和仪器压痕技术(IIT)对其化学和力学性能进行了表征。x射线衍射谱和电子衍射图显示，两种薄膜均存在面心立方结构的Ti (1-x) Al x N相。在金属模式下，涂层表现出优先的(111)平面取向，在复合模式下变为(200)平面取向。反应性气体分压影响了优先取向的变化。
{"title":"Change with the Reactive Deposition Mode in Crystallographic and Mechanical Properties of Titanium Aluminum Nitride Coatings Obtained Via Grid-Assisted Magnetron Sputtering","authors":"M. Moretti, J. Sagás, A.A.C. Recco","doi":"10.1590/1980-5373-mr-2022-0500","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0500","url":null,"abstract":"Thin films of titanium aluminum nitride (Ti (1-x) Al x N) were deposited on silicon, copper, and plasma nitrided AISI D2 tool steel substrates through reactive direct current grid-assisted magnetron sputtering. The depositions were performed in the metal and compound modes using nitrogen flow rates of (7.2 ± 0.1) sccm and (6.8 ± 0.2) sccm, respectively. The relations between the process parameters and the crystallographic orientation were investigated. Chemical and mechanical properties were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and instrumented indentation technique (IIT). X-ray diffraction spectra and electron diffraction patterns revealed the presence of a Ti (1-x) Al x N phase with a face-centered cubic structure in both films. In metal mode, the coatings exhibited a preferential (111) plane orientation, changing to (200) in the compound mode. The change in preferential orientation was influenced by the reactive gas partial pressure.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67303298","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 : 2023-06-19DOI: 10.1590/1980-5373-mr-2022-0487
Ana Clara de Paula Lima, D. Thomazini, A. Chinelatto, M. Gelfuso
Ca 3 Co 4 O 9 powders and ceramics were synthesized and sintered using microwave-assisted heating method.Another batch of powders was calcined by the conventional heating method and this powder was used to produce ceramics sintered by microwave sintering aiming to compare with those prepared by microwave method. The formation of the phases based on calcination method and time was assessed by X-ray diffractometry. The synthesis and sintering methods affected various properties of the ceramics, including grain size, density, phase amount, Seebeck coefficient, thermal conductivity and electrical conductivity. Microwave heating method reduced the time required for the powder synthesis and sintering of ceramics. Ceramics produced using powder obtained by the conventional method presented Figure of Merit (ZT) values of approximately 0.04. However, these values were reduced for the ceramics produced by microwave heating reaching a value of about 0.02. The evaluation of the thermoelectric properties of the Ca 3 Co 4 O 9 ceramics suggests that the main issue to enhance the Figure of Merit of the CCO ceramics is related to density and Ca 3 Co 4 O 9 phase amount present in the ceramics.
{"title":"Thermoelectric Properties of Ca3Co4O9 Using Microwave Synthesis and Sintering","authors":"Ana Clara de Paula Lima, D. Thomazini, A. Chinelatto, M. Gelfuso","doi":"10.1590/1980-5373-mr-2022-0487","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0487","url":null,"abstract":"Ca 3 Co 4 O 9 powders and ceramics were synthesized and sintered using microwave-assisted heating method.Another batch of powders was calcined by the conventional heating method and this powder was used to produce ceramics sintered by microwave sintering aiming to compare with those prepared by microwave method. The formation of the phases based on calcination method and time was assessed by X-ray diffractometry. The synthesis and sintering methods affected various properties of the ceramics, including grain size, density, phase amount, Seebeck coefficient, thermal conductivity and electrical conductivity. Microwave heating method reduced the time required for the powder synthesis and sintering of ceramics. Ceramics produced using powder obtained by the conventional method presented Figure of Merit (ZT) values of approximately 0.04. However, these values were reduced for the ceramics produced by microwave heating reaching a value of about 0.02. The evaluation of the thermoelectric properties of the Ca 3 Co 4 O 9 ceramics suggests that the main issue to enhance the Figure of Merit of the CCO ceramics is related to density and Ca 3 Co 4 O 9 phase amount present in the ceramics.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67303223","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 : 2023-06-19DOI: 10.1590/1980-5373-mr-2023-0137
B. R. Spirandeli, E. Martins, L. M. Dona', R. G. Ribas, T. Campos, E. Esposito, G. Thim, D. Tada, E. S. Trichês
Bacterial infections after implant surgical procedures are a complication observed in many surgeries to treat bone injuries or diseases. Bacteria can attach to the surface of the implant producing biofilms, and if treatment with antibiotics does not work, further surgery is necessary to remove the infected implant. Among the biomaterials for bone implants, bioceramics based on calcium phosphates (CaPs) such as β-TCP stand out, due to their chemical similarity with bone and high bioresorbability. β-TCP has the characteristic of easily accommodating in its crystalline structure reasonable amounts of doping elements, such as monovalent and trivalent ions, which makes it an efficient transporter of drugs, molecules, and therapeutic ions The objective of this work was the incorporation of bioactive glass (BG 45S5) via sol-gel and silver nanoparticles (Ag-NPs) in β-TCP scaffolds, aiming to confer antimicrobial activity to the scaffolds, without prejudice to biocompatibility. XRD and FT-IR analysis indicated structural changes after the incorporation of BG 45S5 and Ag-NPs in β-TCP scaffolds, and these compounds induced the partial transformation of the β-TCP phase into α-TCP phase and the formation of sodium-calcium silicates and silver silicates. The FT-IR spectra showed characteristic bands of α-TCP after incorporation, in addition to the predominant bands of β-TCP. Biocompatibility after incorporation of BG 45S5 was improved, with a significant increase in cell viability. After the incorporation of Ag-NPs, cell viability was maintained at an acceptable level, no cytotoxic behavior was observed, and the scaffolds showed antibacterial and antifungal activity. The results indicate that BG 45S5 and the Ag-NPs incorporated showed a synergistic behavior, conferring antimicrobial activity to the scaffolds without compromising biocompatibility, showing great potential for applicability in tissue engineering.
{"title":"Synergistic Effect of Incorporation of BG 45S5 and Silver Nanoparticles on β-TCP Scaffolds: Structural Characterization and Evaluation of Antimicrobial Activity and Biocompatibility","authors":"B. R. Spirandeli, E. Martins, L. M. Dona', R. G. Ribas, T. Campos, E. Esposito, G. Thim, D. Tada, E. S. Trichês","doi":"10.1590/1980-5373-mr-2023-0137","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2023-0137","url":null,"abstract":"Bacterial infections after implant surgical procedures are a complication observed in many surgeries to treat bone injuries or diseases. Bacteria can attach to the surface of the implant producing biofilms, and if treatment with antibiotics does not work, further surgery is necessary to remove the infected implant. Among the biomaterials for bone implants, bioceramics based on calcium phosphates (CaPs) such as β-TCP stand out, due to their chemical similarity with bone and high bioresorbability. β-TCP has the characteristic of easily accommodating in its crystalline structure reasonable amounts of doping elements, such as monovalent and trivalent ions, which makes it an efficient transporter of drugs, molecules, and therapeutic ions The objective of this work was the incorporation of bioactive glass (BG 45S5) via sol-gel and silver nanoparticles (Ag-NPs) in β-TCP scaffolds, aiming to confer antimicrobial activity to the scaffolds, without prejudice to biocompatibility. XRD and FT-IR analysis indicated structural changes after the incorporation of BG 45S5 and Ag-NPs in β-TCP scaffolds, and these compounds induced the partial transformation of the β-TCP phase into α-TCP phase and the formation of sodium-calcium silicates and silver silicates. The FT-IR spectra showed characteristic bands of α-TCP after incorporation, in addition to the predominant bands of β-TCP. Biocompatibility after incorporation of BG 45S5 was improved, with a significant increase in cell viability. After the incorporation of Ag-NPs, cell viability was maintained at an acceptable level, no cytotoxic behavior was observed, and the scaffolds showed antibacterial and antifungal activity. The results indicate that BG 45S5 and the Ag-NPs incorporated showed a synergistic behavior, conferring antimicrobial activity to the scaffolds without compromising biocompatibility, showing great potential for applicability in tissue engineering.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"57 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67305317","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 : 2023-06-02DOI: 10.1590/1980-5373-mr-2022-0494
T. N. Lima, B. Callegari, L. Folle, Y. Santos, Luiz Gustavo Souza Zamorano, B. C. D. S. Silva, R. Coelho
,
{"title":"Microstructural Evolution of a Hot-Stamped Boron Steel Automotive Part and Its Influence on Corrosion Properties and Tempering Behavior","authors":"T. N. Lima, B. Callegari, L. Folle, Y. Santos, Luiz Gustavo Souza Zamorano, B. C. D. S. Silva, R. Coelho","doi":"10.1590/1980-5373-mr-2022-0494","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0494","url":null,"abstract":",","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67303100","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 : 2023-05-26DOI: 10.1590/1980-5373-mr-2023-0106
Ênio Brogni, R. C. Duarte, R. Cercena, Emerson Colonetti, M. Peterson, M. Cargnin, A. Dal-Bó
Currently, the overheating detection of electric system components is performed using thermal imaging devices, which depend on on-site regulation parameters, require skilled operators and suitable weather conditions. The development and application of innovative technologies to monitor hotspots has highlighted the use of sensors based on thermosensitive materials. In this study, a temperature sensor with thermochromic coating was developed. Thermochromic sensors covered with a varnish layer and nano-titanium oxide, in addition to thermochromic paint, were produced. A 2 3 experimental design was established to assess the performance of thermochromic sensors under artificial weathering conditions. Color measurements of the coatings were performed using the CIELAB method. Fourier-transform infrared (FTIR), UV-Vis (Ultraviolet-Visible), (thermogravimetric TGA, and Differential Scanning Calorimetry (DSC) analyses were performed on the sensors exposed to photodegradation to detect changes in the thermochromic coatings. The sensors exposed to thermodegradation, and salt spray weathering showed ΔE (total color difference) values below 1.50 points in the presence of TiO 2 . In comparison, the sensors exposed to photodegradation showed ΔE values above 10 points, and UV-Vis analysis revealed changes in the chemical structure of the coatings. These results demonstrate that the varnish layer and TiO 2 can help minimize the degradation effects of temperature, light, and salinity.
{"title":"Production and Weathering Exposure of Thermochromic Coatings Used as Sensors to Protect Electricity Distribution Systems","authors":"Ênio Brogni, R. C. Duarte, R. Cercena, Emerson Colonetti, M. Peterson, M. Cargnin, A. Dal-Bó","doi":"10.1590/1980-5373-mr-2023-0106","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2023-0106","url":null,"abstract":"Currently, the overheating detection of electric system components is performed using thermal imaging devices, which depend on on-site regulation parameters, require skilled operators and suitable weather conditions. The development and application of innovative technologies to monitor hotspots has highlighted the use of sensors based on thermosensitive materials. In this study, a temperature sensor with thermochromic coating was developed. Thermochromic sensors covered with a varnish layer and nano-titanium oxide, in addition to thermochromic paint, were produced. A 2 3 experimental design was established to assess the performance of thermochromic sensors under artificial weathering conditions. Color measurements of the coatings were performed using the CIELAB method. Fourier-transform infrared (FTIR), UV-Vis (Ultraviolet-Visible), (thermogravimetric TGA, and Differential Scanning Calorimetry (DSC) analyses were performed on the sensors exposed to photodegradation to detect changes in the thermochromic coatings. The sensors exposed to thermodegradation, and salt spray weathering showed ΔE (total color difference) values below 1.50 points in the presence of TiO 2 . In comparison, the sensors exposed to photodegradation showed ΔE values above 10 points, and UV-Vis analysis revealed changes in the chemical structure of the coatings. These results demonstrate that the varnish layer and TiO 2 can help minimize the degradation effects of temperature, light, and salinity.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"101 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67304503","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 : 2023-05-26DOI: 10.1590/1980-5373-mr-2022-0519
Ali Kifah Ghazi, M. Abass, M. Alali, A. Abood
This paper investigated how casting affects ASTM ZA-27 alloy’s tribological performance in dry and lubricated conditions. To this end, varying contact loads and sliding speeds were applied to tribological tests. The ZA-27 alloy was produced using gravity die casting (GDC) and new rheo-casting (NRC) methods. The results showed that the microstructure of GDC ZA-27 alloy is dendritic containing α and η phases. While the NRC alloy microstructure demonstrates a semi-globular structure of fine equiaxed α phase bordered by eutectoid α and η. The NRC alloy achieved an improvement in tensile, hardness, and elongation properties by almost 15%, 20%, and 25%, respectively. Regarding tribological properties, the NRC alloy achieved an enhancement in tribo-behavior by lowering the coefficient of friction (COF) to about 67% than the GDC alloy. Further, the results showed that the wear rate recorded an increment with applied load for both GDC and NRC alloys. Though, the results showed that the wear rate with NRC alloy was lower compared to the GDC alloy with about 84% at 160N normal load. The worn surfaces of NRC alloys were characterized by smooth and shallow wear grooves. While the GDC alloy worn surfaces were rougher and experience deeper grooves and damage.
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