Pub Date : 2019-05-01DOI: 10.4028/www.scientific.net/DF.22.74
R. Tomescu, C. Parvulescu, D. Cristea, B. Bita, Brandus Comanescu, M. Pelteacu
In this paper, we propose a new approach for fabrication processes of microstructures composed of diffractive optical elements (DOE) and security elements. The holographic lithography is combined with laser lithography to obtain highly secured holographic labels for products protection. The secret key is an untraceable and hardly reproducible geometry and can be embedded in the labels or stickers to increase the level of security and diminish the possibility of products counterfeiting. In our process, the holographic structure composed of DOEs, and the key are designed separately by two authorized designers and recombined using double exposure followed by a single development step. The layout of microstructures that composes the security key are known only by the designer.
{"title":"Optimization of Holographic Labels for Security Applications","authors":"R. Tomescu, C. Parvulescu, D. Cristea, B. Bita, Brandus Comanescu, M. Pelteacu","doi":"10.4028/www.scientific.net/DF.22.74","DOIUrl":"https://doi.org/10.4028/www.scientific.net/DF.22.74","url":null,"abstract":"In this paper, we propose a new approach for fabrication processes of microstructures composed of diffractive optical elements (DOE) and security elements. The holographic lithography is combined with laser lithography to obtain highly secured holographic labels for products protection. The secret key is an untraceable and hardly reproducible geometry and can be embedded in the labels or stickers to increase the level of security and diminish the possibility of products counterfeiting. In our process, the holographic structure composed of DOEs, and the key are designed separately by two authorized designers and recombined using double exposure followed by a single development step. The layout of microstructures that composes the security key are known only by the designer.","PeriodicalId":311581,"journal":{"name":"Diffusion Foundations","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133913325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-01DOI: 10.4028/www.scientific.net/DF.22.55
M. Vlach, V. Kodetová, H. Kudrnová, M. Leibner, M. Vlček, V. Šíma, I. Procházka, J. Málek, V. Očenášek
The effect of cold-rolling on mechanical, thermal, and electrical properties as well as microstructure behaviour of the Al-2.93wt.%Mg-0.34wt.%Mn-0.33wt.%Si-0.22wt.%Fe-0.19wt.%Cr-0.24wt.%Sc-0.06wt.%Zr was studied. The material was investigated during step-by-step isochronal annealing in a temperature range from room temperature up to 540 °C and during isothermal annealing at 200, 450 and 550 °C. Precipitation reactions were studied by electrical resistometry, conductivity, (micro) hardness measurements and differential scanning calorimetry. The hardening effect appears due to the additional precipitation of the Al3Sc and/or Al3(Sc,Zr) particles. The distinct changes in residual resistivity ratio above ~ 330 °C are probably caused by precipitation of the Mn (,Fe,Cr)-containing particles. This precipitation process is highly influenced by cold rolling but it has a negligible effect on hardness. The apparent activation energy values for additional formation of the Al3Sc and/or Al3(Sc,Zr) particles were determined. The kinetics of the Al3(Sc,Zr)-phase precipitation seems to be independent of Mn-and Mg-addition in the studied alloys. A partial recrystallization of the cold-rolled alloy was registered by electron backscatter diffraction after annealing at 550 °C. The initial difference in microhardness introduced by cold rolling is almost removed after annealing at 550 °C/30 min.
{"title":"Mechanical, Thermal and Electrical Characteristics of Conventionally Cast and Cold-Rolled 5754-Sc-Zr Aluminium Alloy","authors":"M. Vlach, V. Kodetová, H. Kudrnová, M. Leibner, M. Vlček, V. Šíma, I. Procházka, J. Málek, V. Očenášek","doi":"10.4028/www.scientific.net/DF.22.55","DOIUrl":"https://doi.org/10.4028/www.scientific.net/DF.22.55","url":null,"abstract":"The effect of cold-rolling on mechanical, thermal, and electrical properties as well as microstructure behaviour of the Al-2.93wt.%Mg-0.34wt.%Mn-0.33wt.%Si-0.22wt.%Fe-0.19wt.%Cr-0.24wt.%Sc-0.06wt.%Zr was studied. The material was investigated during step-by-step isochronal annealing in a temperature range from room temperature up to 540 °C and during isothermal annealing at 200, 450 and 550 °C. Precipitation reactions were studied by electrical resistometry, conductivity, (micro) hardness measurements and differential scanning calorimetry. The hardening effect appears due to the additional precipitation of the Al3Sc and/or Al3(Sc,Zr) particles. The distinct changes in residual resistivity ratio above ~ 330 °C are probably caused by precipitation of the Mn (,Fe,Cr)-containing particles. This precipitation process is highly influenced by cold rolling but it has a negligible effect on hardness. The apparent activation energy values for additional formation of the Al3Sc and/or Al3(Sc,Zr) particles were determined. The kinetics of the Al3(Sc,Zr)-phase precipitation seems to be independent of Mn-and Mg-addition in the studied alloys. A partial recrystallization of the cold-rolled alloy was registered by electron backscatter diffraction after annealing at 550 °C. The initial difference in microhardness introduced by cold rolling is almost removed after annealing at 550 °C/30 min.","PeriodicalId":311581,"journal":{"name":"Diffusion Foundations","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114495389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-01DOI: 10.4028/www.scientific.net/DF.22.65
Ørnulf Nordseth, I. Chilibon, B. Svensson, Raj Kumar, S. Foss, C. Vasiliu, L. Baschir, D. Savastru, L. Fara, C. Dumitru, S. Fara, Florin Drăgan, M. Filipescu, R. Trusca
Cuprous oxide (Cu2O) has a high optical absorption coefficient and favourable electrical properties, which make Cu2O thin films attractive for photovoltaic applications. Using reactive radio-frequency magnetron sputtering, high quality Cu2O thin films with good carrier transport properties were prepared. This paper presents the characteristics of Cu2O thin films that were sputter deposited on quartz substrates and subjected to post-deposition rapid thermal annealing. The thickness of the thin films and the optical constants were determined by ellipsometry spectroscopy (SE). The optical transmittance increased in lower wavelength region after annealing at 900 ̊C in rapid thermal annealing (RTA). The structural and morphological properties of the Cu2O thin films were investigated by electronic scanning microscopy (SEM) and atomic force microscopy (AFM), whereas elemental analysis was performed by X-ray fluorescence spectroscopy (XRF). The carrier mobility, carrier density and film resistivity were changed after post-deposition rapid thermal annealing from respectively ~14 cm2/Vs, ~2.3 x 1015 cm-3 and ~193 Ωcm for the as-deposited Cu2O film to ~49 cm2/Vs, ~5.0 x 1014 cm-3 and ~218 Ωcm for the annealed Cu2O film. The investigation suggests that the sputter-deposited Cu2O thin films have good potential for application as absorber layers in solar cells.
氧化亚铜(Cu2O)具有较高的光学吸收系数和良好的电性能，这使得Cu2O薄膜在光伏应用中具有吸引力。采用反应式射频磁控溅射法制备了具有良好载流子输运性能的高质量Cu2O薄膜。本文介绍了在石英衬底上溅射沉积Cu2O薄膜并进行沉积后快速热退火的特性。利用椭偏光谱(SE)测定了薄膜的厚度和光学常数。900℃快速热退火(RTA)后，在较低波长区域的透射率增加。采用电子扫描显微镜(SEM)和原子力显微镜(AFM)研究了Cu2O薄膜的结构和形态特性，并用x射线荧光光谱(XRF)进行了元素分析。在沉积后快速热退火后，载流子迁移率、载流子密度和薄膜电阻率分别从~14 cm2/V、~2.3 x 1015 cm-3和~193 cm变为~49 cm2/V、~5.0 x 1014 cm-3和~218 cm Ω。研究表明，溅射沉积的Cu2O薄膜作为太阳能电池的吸收层具有良好的应用潜力。
{"title":"Characterization of Cuprous Oxide Thin Films for Application in Solar Cells","authors":"Ørnulf Nordseth, I. Chilibon, B. Svensson, Raj Kumar, S. Foss, C. Vasiliu, L. Baschir, D. Savastru, L. Fara, C. Dumitru, S. Fara, Florin Drăgan, M. Filipescu, R. Trusca","doi":"10.4028/www.scientific.net/DF.22.65","DOIUrl":"https://doi.org/10.4028/www.scientific.net/DF.22.65","url":null,"abstract":"Cuprous oxide (Cu2O) has a high optical absorption coefficient and favourable electrical properties, which make Cu2O thin films attractive for photovoltaic applications. Using reactive radio-frequency magnetron sputtering, high quality Cu2O thin films with good carrier transport properties were prepared. This paper presents the characteristics of Cu2O thin films that were sputter deposited on quartz substrates and subjected to post-deposition rapid thermal annealing. The thickness of the thin films and the optical constants were determined by ellipsometry spectroscopy (SE). The optical transmittance increased in lower wavelength region after annealing at 900 ̊C in rapid thermal annealing (RTA). The structural and morphological properties of the Cu2O thin films were investigated by electronic scanning microscopy (SEM) and atomic force microscopy (AFM), whereas elemental analysis was performed by X-ray fluorescence spectroscopy (XRF). The carrier mobility, carrier density and film resistivity were changed after post-deposition rapid thermal annealing from respectively ~14 cm2/Vs, ~2.3 x 1015 cm-3 and ~193 Ωcm for the as-deposited Cu2O film to ~49 cm2/Vs, ~5.0 x 1014 cm-3 and ~218 Ωcm for the annealed Cu2O film. The investigation suggests that the sputter-deposited Cu2O thin films have good potential for application as absorber layers in solar cells.","PeriodicalId":311581,"journal":{"name":"Diffusion Foundations","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114673993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-01DOI: 10.4028/www.scientific.net/DF.22.19
A. S. Guimarães, João M.P.Q. Delgado, V. P. D. Freitas, A. Azevedo
The phenomena of transport in porous media arises in many diverse fields of science and engineering, ranging from agricultural, biomedical, building, ceramic, chemical, and petroleum engineering to food and soil science. Several authors provide an extensive description of the problems involving porous media. For building engineering, obtaining a good understanding of moisture transport in building envelopes is becoming one of the most important tasks. In the last few decades, many studies investigating moisture transport in building envelopes have been published, which have helped to improve overall building envelope design. This work presents a brief review of these studies.
{"title":"Influence of Different Joints on Moisture Transport in Building Walls - A Brief Review","authors":"A. S. Guimarães, João M.P.Q. Delgado, V. P. D. Freitas, A. Azevedo","doi":"10.4028/www.scientific.net/DF.22.19","DOIUrl":"https://doi.org/10.4028/www.scientific.net/DF.22.19","url":null,"abstract":"The phenomena of transport in porous media arises in many diverse fields of science and engineering, ranging from agricultural, biomedical, building, ceramic, chemical, and petroleum engineering to food and soil science. Several authors provide an extensive description of the problems involving porous media. For building engineering, obtaining a good understanding of moisture transport in building envelopes is becoming one of the most important tasks. In the last few decades, many studies investigating moisture transport in building envelopes have been published, which have helped to improve overall building envelope design. This work presents a brief review of these studies.","PeriodicalId":311581,"journal":{"name":"Diffusion Foundations","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121832646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-01DOI: 10.4028/www.scientific.net/DF.22.24
A. Chaus, M. Sahul, Matej Bračík
The influence of annealing at 1200 °C for 2, 4 and 8 h on the carbide microstructure of AISI M2 type high-speed steel obtained by both the foundry and conventional metallurgy technologies has been studied. The primary focus was on the kinetics of eutectic carbide decomposition and dissolution in both the cast and wrought M2 high-speed steels under the effect of high temperature.
{"title":"Diffusion Induced Changes in Cast and Wrought M2 High-Speed Steel Subject to Homogenisation Annealing","authors":"A. Chaus, M. Sahul, Matej Bračík","doi":"10.4028/www.scientific.net/DF.22.24","DOIUrl":"https://doi.org/10.4028/www.scientific.net/DF.22.24","url":null,"abstract":"The influence of annealing at 1200 °C for 2, 4 and 8 h on the carbide microstructure of AISI M2 type high-speed steel obtained by both the foundry and conventional metallurgy technologies has been studied. The primary focus was on the kinetics of eutectic carbide decomposition and dissolution in both the cast and wrought M2 high-speed steels under the effect of high temperature.","PeriodicalId":311581,"journal":{"name":"Diffusion Foundations","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133721636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-01DOI: 10.4028/www.scientific.net/DF.22.109
Wesley R Walker, R. Marloth, Ye Thura Hein, O. Es-Said
This study aimed to characterize the effects of incomplete solution treatment time on the tensile behavior of 2195 Al-Li alloy. Two sets of plates of 2195 Al-Li alloy received solution heat treatment. One set received the prescribed treatment, held in the furnace for 30 minutes after the material had reached 507°C. The other set was in the furnace for only 30 minutes and did not reach 507°C until after about 15 to 20 minutes. Both set of plates were water quenched. Samples from the plates were then stretched 2.5-3% or 6%, rolled 6%, and rolled 24%, at 0°, 45°, and 90° relative to the rolling direction of the as-received material. The samples were aged at 143°C for 36 hours and air-cooled. Tensile specimens were milled out at 0°, 45°, and 90° relative to the original rolling direction. Tensile testing was performed on all samples. The incomplete heat treatment (incomplete solution treatment) resulted in a significant reduction in strength. This was probably due to the formation of fewer T1 precipitates after aging, thereby reducing the amount which could nucleate during cold work. The fully heat treated samples had higher percent yield strength, ultimate strength, and elongation.
{"title":"The Effect of Incomplete Solution Treatment on the Tensile Behavior and Mechanical Anisotropy of 2195 Aluminum Lithium Alloy","authors":"Wesley R Walker, R. Marloth, Ye Thura Hein, O. Es-Said","doi":"10.4028/www.scientific.net/DF.22.109","DOIUrl":"https://doi.org/10.4028/www.scientific.net/DF.22.109","url":null,"abstract":"This study aimed to characterize the effects of incomplete solution treatment time on the tensile behavior of 2195 Al-Li alloy. Two sets of plates of 2195 Al-Li alloy received solution heat treatment. One set received the prescribed treatment, held in the furnace for 30 minutes after the material had reached 507°C. The other set was in the furnace for only 30 minutes and did not reach 507°C until after about 15 to 20 minutes. Both set of plates were water quenched. Samples from the plates were then stretched 2.5-3% or 6%, rolled 6%, and rolled 24%, at 0°, 45°, and 90° relative to the rolling direction of the as-received material. The samples were aged at 143°C for 36 hours and air-cooled. Tensile specimens were milled out at 0°, 45°, and 90° relative to the original rolling direction. Tensile testing was performed on all samples. The incomplete heat treatment (incomplete solution treatment) resulted in a significant reduction in strength. This was probably due to the formation of fewer T1 precipitates after aging, thereby reducing the amount which could nucleate during cold work. The fully heat treated samples had higher percent yield strength, ultimate strength, and elongation.","PeriodicalId":311581,"journal":{"name":"Diffusion Foundations","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125287312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-01DOI: 10.4028/www.scientific.net/DF.22.48
M. Mandel, Volodymyr Kietov, L. Krüger
The electrochemical current noise signal of a high-alloy cast steel was investigated in a 0.1 M sulfuric acid solution and in a 5 wt.% sodium chloride solution. In the sulfuric acid solution, the current time signal reveals characteristic spikes of high amplitudes. In the chloride containing solution, spontaneous power drops with a subsequent recovery of comparatively low intensity characterize the noise signal. Both noise records were analyzed by the discrete wavelet transform. For the noise signal in the sulfuric acid solution, the received wavelet coefficients exhibit the highest values in the fine scale, which signal the dominance of short-time corrosion events that were attributed to the observed hydrogen bubble evolution. In the chloride containing medium, the signal decomposition by the wavelet analysis reveals the highest coefficients predominantly in the coarse scale, indicating a preferred initiation of corrosion processes of high duration. The subsequent observations by scanning electron microscopy, reveal an attack by micro pitting, which is associated with the noise events.
{"title":"Discrete Wavelet Analysis of Electrochemical Current Noise of a High-Alloy Cast Steel in Sulfuric Acid and Sodium Chloride Solution","authors":"M. Mandel, Volodymyr Kietov, L. Krüger","doi":"10.4028/www.scientific.net/DF.22.48","DOIUrl":"https://doi.org/10.4028/www.scientific.net/DF.22.48","url":null,"abstract":"The electrochemical current noise signal of a high-alloy cast steel was investigated in a 0.1 M sulfuric acid solution and in a 5 wt.% sodium chloride solution. In the sulfuric acid solution, the current time signal reveals characteristic spikes of high amplitudes. In the chloride containing solution, spontaneous power drops with a subsequent recovery of comparatively low intensity characterize the noise signal. Both noise records were analyzed by the discrete wavelet transform. For the noise signal in the sulfuric acid solution, the received wavelet coefficients exhibit the highest values in the fine scale, which signal the dominance of short-time corrosion events that were attributed to the observed hydrogen bubble evolution. In the chloride containing medium, the signal decomposition by the wavelet analysis reveals the highest coefficients predominantly in the coarse scale, indicating a preferred initiation of corrosion processes of high duration. The subsequent observations by scanning electron microscopy, reveal an attack by micro pitting, which is associated with the noise events.","PeriodicalId":311581,"journal":{"name":"Diffusion Foundations","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114671253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-01DOI: 10.4028/www.scientific.net/DF.22.39
F. Otmane, S. Triaa, A. Maali, B. Rekioua
This study reports on the elaboration and characterization of bulk nanocomposites samples obtained by dispersion of metallic powders at the nanoscale as reinforcements in a polymer matrix. Elemental Fe powders were successfully nanostructured via high-energy ball milling. Structural characterization of the produced powders was conducted using X-Ray Diffraction (XRD) analysis and Scanning Electron Microscopy (SEM). The Halder-Wagner approach was adopted to determine the powder’s average grain size, internal strain, lattice parameters and the mixing factors. Structural parameters evolution and morphological changes according to milling progression are discussed. Bulk nanocomposites samples were shaped in a home moulder by dispersion of coarse Fe and nanostructured Fe powders in a continuous matrix of commercial epoxy resin. The obtained bulk samples match the metallic X-band wave-guide WR-90 dimensions used for electromagnetic characterization. The two-port Sij scattering parameters were measured via an Agilent 8791 ES network analyzer. The measured scattering parameters served to calculate the loss factor of samples and to extract the dielectric permittivity via the Nicholson-Ross-Weir conversion. Spectra evolution of the scattering parameters, the loss factor and the dielectric constant for epoxy resin with coarse Fe and nanostructured Fe reinforcements are commented.
{"title":"Synthesis and Characterization of Fe-Based Nanocomposites","authors":"F. Otmane, S. Triaa, A. Maali, B. Rekioua","doi":"10.4028/www.scientific.net/DF.22.39","DOIUrl":"https://doi.org/10.4028/www.scientific.net/DF.22.39","url":null,"abstract":"This study reports on the elaboration and characterization of bulk nanocomposites samples obtained by dispersion of metallic powders at the nanoscale as reinforcements in a polymer matrix. Elemental Fe powders were successfully nanostructured via high-energy ball milling. Structural characterization of the produced powders was conducted using X-Ray Diffraction (XRD) analysis and Scanning Electron Microscopy (SEM). The Halder-Wagner approach was adopted to determine the powder’s average grain size, internal strain, lattice parameters and the mixing factors. Structural parameters evolution and morphological changes according to milling progression are discussed. Bulk nanocomposites samples were shaped in a home moulder by dispersion of coarse Fe and nanostructured Fe powders in a continuous matrix of commercial epoxy resin. The obtained bulk samples match the metallic X-band wave-guide WR-90 dimensions used for electromagnetic characterization. The two-port Sij scattering parameters were measured via an Agilent 8791 ES network analyzer. The measured scattering parameters served to calculate the loss factor of samples and to extract the dielectric permittivity via the Nicholson-Ross-Weir conversion. Spectra evolution of the scattering parameters, the loss factor and the dielectric constant for epoxy resin with coarse Fe and nanostructured Fe reinforcements are commented.","PeriodicalId":311581,"journal":{"name":"Diffusion Foundations","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130714235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-01DOI: 10.4028/www.scientific.net/DF.22.84
S. Janakiram, J. Gautam, A. Miroux, J. Moerman, L. Kestens
Formability had been important property of metals which is attributed to the texture development during thermomechanical processing particularly during hot rolling and cold rolling. In the present paper, the high strength steels with different carbon and manganese composition have been hot rolled above and below of austenite recrystallization temperature and followed by fast cooling up to different coiling temperature to get hot bands with different texture and two phase microstructure consisting ferrite with pearlite, bainite and martensite. Subsequently, these hot bands were cold rolled with 80 percent under plain strain condition. The microstructure of cold rolled sheets samples were analyzed using scanning electron microscope and showed the cold rolled microstructure with strong pancaked of two phase which was carried from the hot rolling. Cold rolled texture in ferrite pearlite microstructure is completely replaced by new texture components from hot rolled condition without the effect of Tnr. Hot rolled texture was retained in ferrite-bainite and martensite microstructure with the effect of Tnr. Increase in alloy chemistry weakens the texture intensity in ferrite pearlite/bainite microstructure. Whereas increase in alloy chemistry strengthens the texture intensity in ferrite martensite microstructure.
{"title":"Microstructure and Texture Control in Cold Rolled High Strength Steels","authors":"S. Janakiram, J. Gautam, A. Miroux, J. Moerman, L. Kestens","doi":"10.4028/www.scientific.net/DF.22.84","DOIUrl":"https://doi.org/10.4028/www.scientific.net/DF.22.84","url":null,"abstract":"Formability had been important property of metals which is attributed to the texture development during thermomechanical processing particularly during hot rolling and cold rolling. In the present paper, the high strength steels with different carbon and manganese composition have been hot rolled above and below of austenite recrystallization temperature and followed by fast cooling up to different coiling temperature to get hot bands with different texture and two phase microstructure consisting ferrite with pearlite, bainite and martensite. Subsequently, these hot bands were cold rolled with 80 percent under plain strain condition. The microstructure of cold rolled sheets samples were analyzed using scanning electron microscope and showed the cold rolled microstructure with strong pancaked of two phase which was carried from the hot rolling. Cold rolled texture in ferrite pearlite microstructure is completely replaced by new texture components from hot rolled condition without the effect of Tnr. Hot rolled texture was retained in ferrite-bainite and martensite microstructure with the effect of Tnr. Increase in alloy chemistry weakens the texture intensity in ferrite pearlite/bainite microstructure. Whereas increase in alloy chemistry strengthens the texture intensity in ferrite martensite microstructure.","PeriodicalId":311581,"journal":{"name":"Diffusion Foundations","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129182947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-01DOI: 10.4028/www.scientific.net/DF.22.1
M. Ciesielski, B. Mochnacki
Solidification and cooling processes proceeding in the metal domain can be described in different ways. One of them consists in the application of the Fourier-type equation in which the additional term (source function) controlling the solidification process is introduced. In this paper this type of energy equation is used, but for the phase change modeling the equation discussed is in some way transformed. Such a modification is possible if one considers the pure metal for which the solidification point is a constant value. The numerical model used at the stage of computations is based on the Control Volume Method. In the final part of the paper, examples of computations are shown.
{"title":"A New Approach to the Numerical Modeling of Pure Metal Solidification","authors":"M. Ciesielski, B. Mochnacki","doi":"10.4028/www.scientific.net/DF.22.1","DOIUrl":"https://doi.org/10.4028/www.scientific.net/DF.22.1","url":null,"abstract":"Solidification and cooling processes proceeding in the metal domain can be described in different ways. One of them consists in the application of the Fourier-type equation in which the additional term (source function) controlling the solidification process is introduced. In this paper this type of energy equation is used, but for the phase change modeling the equation discussed is in some way transformed. Such a modification is possible if one considers the pure metal for which the solidification point is a constant value. The numerical model used at the stage of computations is based on the Control Volume Method. In the final part of the paper, examples of computations are shown.","PeriodicalId":311581,"journal":{"name":"Diffusion Foundations","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116284069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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