Abstract A fabrication process of polycarbonate (PC) light guide plate (LGP) incorporating fluorescent quantum dots (QDs) is presented in this study. QD-PC composite pellets with dimension of 500 to 2500 μm were first prepared from a mixture of polyethylene-treated QDs and PC resin powder, followed by injection moulding to form a QD-LGP between 340 and 295 °C. The fabricated QD-LGPs demonstrated dual functions of light guiding and QD colour conversion, which is conventionally provided by a LGP covered with an additional QD diffuser film. By directly embedding QDs into a LGP, it was found that a rather low cadmium content around 41 ppm was sufficient to provide a uniform backlighting for a liquid-crystal display with a colour gamut of ~115% NTSC standard.
{"title":"Polycarbonate Light Guide Plates with Embedded Quantum Dots Fabricated by Large-Scale Injection Moulding for Wide Colour Gamut Displays","authors":"Guang-Hong Chen, Shao Yang, Chang‐Wei Yeh, Shih‐Jung Ho, Meng-Chi Liu, Hsueh‐Shih Chen","doi":"10.2139/ssrn.3805237","DOIUrl":"https://doi.org/10.2139/ssrn.3805237","url":null,"abstract":"Abstract A fabrication process of polycarbonate (PC) light guide plate (LGP) incorporating fluorescent quantum dots (QDs) is presented in this study. QD-PC composite pellets with dimension of 500 to 2500 μm were first prepared from a mixture of polyethylene-treated QDs and PC resin powder, followed by injection moulding to form a QD-LGP between 340 and 295 °C. The fabricated QD-LGPs demonstrated dual functions of light guiding and QD colour conversion, which is conventionally provided by a LGP covered with an additional QD diffuser film. By directly embedding QDs into a LGP, it was found that a rather low cadmium content around 41 ppm was sufficient to provide a uniform backlighting for a liquid-crystal display with a colour gamut of ~115% NTSC standard.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"19 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76998154","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}
Seungki Jo, Hyun-sik Kim, Yurian Kim, Sang‐il Kim, Kyu Hyoung Lee
Bipolar conduction in Bi-Te-based alloys is a critical barrier to high conversion efficiency in thermoelectric power generation applications. Herein, we investigate the effect of compositional tuning of Te/Se ratio on bipolar conduction in n-type Cu0.008Bi2(Te,Se)3 alloys. Based on the two-band model and Callaway model, we found that electronic and thermal transports of minority carriers (holes) were gradually decreased with an increase in Se content. The high-temperature power factor of Se-rich Cu0.008Bi2Te2.1Se0.9 was higher in value compared to reference Cu0.008Bi2Te2.7Se0.3 due to the weighted mobility ratio increase, and its bipolar thermal conductivity was significantly reduced simultaneously. As a result, a peak figure of merit (zT) of 0.92 was obtained at 440 K in Cu0.008Bi2Te2.1Se0.9.
{"title":"Se-Induced Enhancement of the High-Temperature Thermoelectric Performance of n-type Cu 0.008Bi 2(Te,Se) 3 Alloys Due to Suppressed Bipolar Conduction","authors":"Seungki Jo, Hyun-sik Kim, Yurian Kim, Sang‐il Kim, Kyu Hyoung Lee","doi":"10.2139/ssrn.3787880","DOIUrl":"https://doi.org/10.2139/ssrn.3787880","url":null,"abstract":"Bipolar conduction in Bi-Te-based alloys is a critical barrier to high conversion efficiency in thermoelectric power generation applications. Herein, we investigate the effect of compositional tuning of Te/Se ratio on bipolar conduction in <i>n</i>-type Cu<sub>0.008</sub>Bi<sub>2</sub>(Te,Se)<sub>3</sub> alloys. Based on the two-band model and Callaway model, we found that electronic and thermal transports of minority carriers (holes) were gradually decreased with an increase in Se content. The high-temperature power factor of Se-rich Cu<sub>0.008</sub>Bi<sub>2</sub>Te<sub>2.1</sub>Se<sub>0.9</sub> was higher in value compared to reference Cu<sub>0.008</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub> due to the weighted mobility ratio increase, and its bipolar thermal conductivity was significantly reduced simultaneously. As a result, a peak figure of merit (<i>zT</i>) of 0.92 was obtained at 440 K in Cu<sub>0.008</sub>Bi<sub>2</sub>Te<sub>2.1</sub>Se<sub>0.9</sub>.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74752417","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}
Haijun Wu, Usama Shakeel, Quan Zhang, Kai Zhang, Xia Xu, Jian Xu
The production of bio-oil from poplar sawdust Under direct/stepwise hydrothermal liquefaction (HTL) with Na2CO3 or Na2CO3/Fe as catalyst was investigated. The results showed that as the increase of liquefaction temperature in the stepwise HTL, the carbon content in heavy oil (HO) gradually increased, while the oxygen in light oil (LO) kept decreasing. The highest total bio-oil yield of 57.09% was obtained from the stepwise Na2CO3/Fe-catalyzed HTL with a residence time of 20 min. Via GC-MS analysis, it was found that the Na2CO3 catalyzed stepwise HTL dramatically improved the yield of dibutyl phthalate. While the Na2CO3/Fe catalyzed HTL helped promote the production of phthalic acid, butyl 2-ethylhexyl ester and phthalic acid, diisobutyl ester.
{"title":"Catalytic Degradation of Poplar by Fe and Fe/Na 2CO 3 Under Different Hydrothermal Liquefaction Processes","authors":"Haijun Wu, Usama Shakeel, Quan Zhang, Kai Zhang, Xia Xu, Jian Xu","doi":"10.2139/ssrn.3935538","DOIUrl":"https://doi.org/10.2139/ssrn.3935538","url":null,"abstract":"The production of bio-oil from poplar sawdust Under direct/stepwise hydrothermal liquefaction (HTL) with Na2CO3 or Na2CO3/Fe as catalyst was investigated. The results showed that as the increase of liquefaction temperature in the stepwise HTL, the carbon content in heavy oil (HO) gradually increased, while the oxygen in light oil (LO) kept decreasing. The highest total bio-oil yield of 57.09% was obtained from the stepwise Na2CO3/Fe-catalyzed HTL with a residence time of 20 min. Via GC-MS analysis, it was found that the Na2CO3 catalyzed stepwise HTL dramatically improved the yield of dibutyl phthalate. While the Na2CO3/Fe catalyzed HTL helped promote the production of phthalic acid, butyl 2-ethylhexyl ester and phthalic acid, diisobutyl ester.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"109 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83653197","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}
An azo dye bearing coumarin moieties were prepared by diazotization of 4-Nitro aniline using Amberlyst-15 as an acid catalyst then coupling of the obtained diazonium salt with coumarin. The obtained dye were characterized via UV-Vis, FT-IR, and 1H and 13C NMR spectroscopy This green methodology aims to overcome the limitations of the diazotisation traditional method such as using of strong acids and toxic solvents, modest yields, and difficult purification, Moreover, the attractive advantages of the process include mild conditions with excellent conversions, avoidance of harmful acids, simple product isolation process, selective, reduce by-products, inexpensive procedure and recyclability of the catalyst.
{"title":"An Eco-Friendly Approach for the Synthesis of Azocoumarin Dye Using Cation Exchange Resins","authors":"Fadia Alhaj Hussien","doi":"10.2139/ssrn.3896443","DOIUrl":"https://doi.org/10.2139/ssrn.3896443","url":null,"abstract":"An azo dye bearing coumarin moieties were prepared by diazotization of 4-Nitro aniline using Amberlyst-15 as an acid catalyst then coupling of the obtained diazonium salt with coumarin. The obtained dye were characterized via UV-Vis, FT-IR, and 1H and 13C NMR spectroscopy This green methodology aims to overcome the limitations of the diazotisation traditional method such as using of strong acids and toxic solvents, modest yields, and difficult purification, Moreover, the attractive advantages of the process include mild conditions with excellent conversions, avoidance of harmful acids, simple product isolation process, selective, reduce by-products, inexpensive procedure and recyclability of the catalyst.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75337159","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}
Two successive cycles of deformation were conducted in corresponding stacking fault energy (SFE) ranges dominated by dislocation slip and twinning deformation. This SFE-dependent deformation process yields a sample with high-density dislocations, stacking faults (SFs) and four-fold nanotwins. Dislocation hardening and SFs-assisted acceleration of martensite transformation result in excellent work hardening capacity and consequently high strength. Meanwhile, nanotwins provide superior ductility by alleviating shear strain accumulation and retarding crack initiation. The SFE strategy increased the yield strength of the present sample by 3.1 times without sacrificing ductility, thereby overcoming the strength–ductility tradeoff.
{"title":"Stacking Fault Energy-Dependent Strategy Induces Fourfold Nanotwins to Circumvent Strength-Ductility Tradeoff In Medium Manganese Steel","authors":"Junkui Li, Chen Chen, Zhi-nan Yang, Yan-guo Li, B. Lv, Fucheng Zhang","doi":"10.2139/ssrn.3831014","DOIUrl":"https://doi.org/10.2139/ssrn.3831014","url":null,"abstract":"Two successive cycles of deformation were conducted in corresponding stacking fault energy (SFE) ranges dominated by dislocation slip and twinning deformation. This SFE-dependent deformation process yields a sample with high-density dislocations, stacking faults (SFs) and four-fold nanotwins. Dislocation hardening and SFs-assisted acceleration of martensite transformation result in excellent work hardening capacity and consequently high strength. Meanwhile, nanotwins provide superior ductility by alleviating shear strain accumulation and retarding crack initiation. The SFE strategy increased the yield strength of the present sample by 3.1 times without sacrificing ductility, thereby overcoming the strength–ductility tradeoff.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84382250","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}
This article develops a new generalized mechanical model of the flow of a visco-inert viscously deformed medium. New theoretical methods for describing the visco-inert fluid medium's properties using the distribution function of voltagerelaxation periods and using the operator equations of flow as quite general characteristics of visco-inert media.
{"title":"Generalized Model of the Flow of a Viscous and Inertly Deformed Medium","authors":"Y.D. Khodjaev, S. Kasimov, A. Mirzoev","doi":"10.2139/ssrn.3773387","DOIUrl":"https://doi.org/10.2139/ssrn.3773387","url":null,"abstract":"This article develops a new generalized mechanical model of the flow of a visco-inert viscously deformed medium. New theoretical methods for describing the visco-inert fluid medium's properties using the distribution function of voltagerelaxation periods and using the operator equations of flow as quite general characteristics of visco-inert media.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81377870","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}
Liberty Wu, T. Osada, T. Yokokawa, Yatao Chang, K. Kawagishi
The development of advanced Ni-based superalloys for gas turbine applications is strongly reliant on alloy strength design and optimisation through microstructure control. Herein, a new model of precipitation strengthening in Ni-based superalloys with large amounts of cuboidal γ’ particles is proposed and directly validated using commercial alloy (Alloy720Li)-based single-crystal tie-line model alloys with specially designed γ’ particle sizes and volume fractions. All factors responsible for Ni-based superalloy strengthening, including the γ/γ’ mixture, particle strengthening, and solid solution strengthening are extracted from the compressive stress-strain curves performed over a wide temperature range. The strength increment due to particle strengthening is predicted for five model alloys with various γ’-particle volume fractions, sizes, and shapes. The pair-coupling model assuming the presence of cuboidal γ’ particles accurately predicts alloy strength over a wide temperature range (up to 760 °C) for volume fractions of >45%, whereas the classical model assuming spherical γ’ particles is valid only for volume fractions of <20%. Thus, the former model is much more accurate than classical models across wider volume fractions up to the disc service temperature, contributing to the design of further strengthened superalloys.
{"title":"Modelling the High-Temperature Strengthening of Ni-Based Superalloys With Cuboidal γ’-Phase Particles","authors":"Liberty Wu, T. Osada, T. Yokokawa, Yatao Chang, K. Kawagishi","doi":"10.2139/ssrn.3862297","DOIUrl":"https://doi.org/10.2139/ssrn.3862297","url":null,"abstract":"The development of advanced Ni-based superalloys for gas turbine applications is strongly reliant on alloy strength design and optimisation through microstructure control. Herein, a new model of precipitation strengthening in Ni-based superalloys with large amounts of cuboidal γ’ particles is proposed and directly validated using commercial alloy (Alloy720Li)-based single-crystal tie-line model alloys with specially designed γ’ particle sizes and volume fractions. All factors responsible for Ni-based superalloy strengthening, including the γ/γ’ mixture, particle strengthening, and solid solution strengthening are extracted from the compressive stress-strain curves performed over a wide temperature range. The strength increment due to particle strengthening is predicted for five model alloys with various γ’-particle volume fractions, sizes, and shapes. The pair-coupling model assuming the presence of cuboidal γ’ particles accurately predicts alloy strength over a wide temperature range (up to 760 °C) for volume fractions of >45%, whereas the classical model assuming spherical γ’ particles is valid only for volume fractions of <20%. Thus, the former model is much more accurate than classical models across wider volume fractions up to the disc service temperature, contributing to the design of further strengthened superalloys.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87270687","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}
Liyang Wu, Jianmei Cen, Asad Ali, Jiecai Li, P. Shen
Conducting polymers are commonly used as precursors for preparing carbon-based catalysts and have been used in electrocatalytic water splitting. However, so far, most of the catalytic materials synthesized with the assistance of high polymer conducting polymers are non-self-supporting and have only single-function catalytic effect. Therefore, it is an inevitable trend to synthesize a bifunctional self-supported highly efficient and long-stable water splitting catalyst. Herein, a self-supporting polypyrrole precursor PPy-PW12 was prepared by electrodeposition with phosphotungstic acid as dopant. In addition, the PPy-PW12 precursor was then calcined. The as-prepared W/Ni3(PO4)2@NC/NF electrocatalyst exhibits admirable HER and OER performances with overpotentials of 48 mV for HER and 236 mV for OER to reach a current density of 10 mA cm -2 in 1M KOH solution. Additionally, when W/Ni3(PO4)2@NC/NF is used in overall water splitting as a bifunctional catalyst, it needs only 1.53 V to give a current density of 10 mA cm−2 which is superior to typically integrated Pt/C and RuO2 counterparts. Our work offers a facile strategy to apply W/Ni3(PO4)2@NC/NF as practical bifunctional electrocatalysts for large-scale water splitting.
导电聚合物通常用作制备碳基催化剂的前驱体，并已用于电催化水裂解。然而，迄今为止，在高分子导电聚合物的辅助下合成的催化材料大多是非自支撑的，只有单一功能的催化作用。因此，合成一种双功能、自持、高效、长稳定的水裂解催化剂是必然趋势。以磷钨酸为掺杂剂，电沉积法制备了自支撑型聚吡咯前驱体py - pw12。此外，将py - pw12前驱体进行煅烧。制备的W/Ni3(PO4)2@NC/NF电催化剂表现出良好的HER和OER性能，在1M KOH溶液中，HER的过电位为48 mV, OER的过电位为236 mV，电流密度达到10 mA cm -2。此外，当W/Ni3(PO4)2@NC/NF作为双功能催化剂用于整体水分解时，它只需要1.53 V就能产生10 mA cm−2的电流密度，优于典型集成Pt/C和RuO2。我们的工作提供了一种简单的策略，将W/Ni3(PO4)2@NC/NF用作大规模水分解的实用双功能电催化剂。
{"title":"W/Ni 3(PO 4) 2@NC/NF Nanorods via Electrodeposition with Carbonization as a Bifunctional Catalyst for Electrocatalytic Water Splitting","authors":"Liyang Wu, Jianmei Cen, Asad Ali, Jiecai Li, P. Shen","doi":"10.2139/ssrn.3913052","DOIUrl":"https://doi.org/10.2139/ssrn.3913052","url":null,"abstract":"Conducting polymers are commonly used as precursors for preparing carbon-based catalysts and have been used in electrocatalytic water splitting. However, so far, most of the catalytic materials synthesized with the assistance of high polymer conducting polymers are non-self-supporting and have only single-function catalytic effect. Therefore, it is an inevitable trend to synthesize a bifunctional self-supported highly efficient and long-stable water splitting catalyst. Herein, a self-supporting polypyrrole precursor PPy-PW12 was prepared by electrodeposition with phosphotungstic acid as dopant. In addition, the PPy-PW12 precursor was then calcined. The as-prepared W/Ni3(PO4)2@NC/NF electrocatalyst exhibits admirable HER and OER performances with overpotentials of 48 mV for HER and 236 mV for OER to reach a current density of 10 mA cm -2 in 1M KOH solution. Additionally, when W/Ni3(PO4)2@NC/NF is used in overall water splitting as a bifunctional catalyst, it needs only 1.53 V to give a current density of 10 mA cm−2 which is superior to typically integrated Pt/C and RuO2 counterparts. Our work offers a facile strategy to apply W/Ni3(PO4)2@NC/NF as practical bifunctional electrocatalysts for large-scale water splitting.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86341160","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}
G. Zhao, Xin Xu, D. Dye, P. Rivera-Díaz-del-Castillo, N. Petrinic
Developing lighter, stronger and more ductile aerospace metallic materials is in demand for energy efficiency strategies. Alloys with twinning-induced plasticity (TWIP) and/or transformation-induced plasticity (TRIP) effects have been exploited to defeat the conflict of strength versus ductility, yet very few if any physically informed methods exist to address the complex interactions between transitions. Here we report a facile route to deploy transformation-mediated strengthening in lightweight Ti alloys, which particularly focuses on the controlled activation of TRIP and TWIP via a mechanism-driven modelling approach. New alloys were comparatively developed and presented notable resistances to strain localisation, but interestingly through distinct mechanical characteristics. Specifically, extraordinary strain-hardening rate with a peak value of 2.4 GPa was achieved in Ti-10Mo-5Nb (wt.%), resulting from the synergetic activation of hierarchical transformations. A model integrating TRIP and TWIP was applied to understand the interplays between the transition mechanisms that individually contribute to strength and uniform elongation.
{"title":"Facile Route to Implement Transformation Strengthening in Lightweight Alloys","authors":"G. Zhao, Xin Xu, D. Dye, P. Rivera-Díaz-del-Castillo, N. Petrinic","doi":"10.2139/ssrn.3886367","DOIUrl":"https://doi.org/10.2139/ssrn.3886367","url":null,"abstract":"Developing lighter, stronger and more ductile aerospace metallic materials is in demand for energy efficiency strategies. Alloys with twinning-induced plasticity (TWIP) and/or transformation-induced plasticity (TRIP) effects have been exploited to defeat the conflict of strength versus ductility, yet very few if any physically informed methods exist to address the complex interactions between transitions. Here we report a facile route to deploy transformation-mediated strengthening in lightweight Ti alloys, which particularly focuses on the controlled activation of TRIP and TWIP via a mechanism-driven modelling approach. New alloys were comparatively developed and presented notable resistances to strain localisation, but interestingly through distinct mechanical characteristics. Specifically, extraordinary strain-hardening rate with a peak value of 2.4 GPa was achieved in Ti-10Mo-5Nb (wt.%), resulting from the synergetic activation of hierarchical transformations. A model integrating TRIP and TWIP was applied to understand the interplays between the transition mechanisms that individually contribute to strength and uniform elongation.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83688824","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}
Shiqiu Liu, H. Ding, Ruirun Chen, Jingjie Guo, H. Fu
Strengthening of TiAl-based intermetallic alloy is vital for its broader application, however, microstructural refinement through conventional processes is difficult to further strengthen this intermetallic alloy. Although high-density deformation nanotwin is expected to effectively strengthen it, there is still lack of in-depth understanding about the strengthening mechanism of high-density deformation nanotwin in TiAl-based alloy. Herein the microstructures, room-temperature (RT) tensile properties, tensile fracture behavior, and deformation mechanism of the Ti-45.5Al-4Cr-2.5Nb (at.%) master alloy (M. A.) as well as its continuous casting (C. C.) alloy and the heat-treated alloys were systematically investigated. After the C. C. alloy was annealed at 1250 °C for 2 hours, the volume fraction of (B2+γ) coupled structures in the original grains reached the minimum, the interlamellar spacing was markedly refined; besides, substantial Shockley partial dislocations and stacking faults were generated in γ phase. During RT tension, both the dominant deformation mechanisms of the M. A. and C. C. alloy were dislocation slip, while that of the 2h heat-treated alloy was changed into deformation twinning. High-density deformation nanotwins were generated in the γ phase (especially the γ lamellae) of the 2h heat-treated alloy, which improved the tensile strength of the M. A. by 79%. High-density deformation nanotwins can further strengthen TiAl-based alloy to a large extent, which is mainly attributed to the fact that their batch-to-batch generation in the polycrystalline TiAl-based alloy during tension could considerably relief the stress concentration in addition to effectively improving the work-hardening rate, thus making the work-hardening rate keeping stable.
{"title":"High-Density Deformation Nanotwin Further Improved Tensile Strength of Polycrystalline γ-TiAl-Based Intermetallic Alloy","authors":"Shiqiu Liu, H. Ding, Ruirun Chen, Jingjie Guo, H. Fu","doi":"10.2139/ssrn.3821950","DOIUrl":"https://doi.org/10.2139/ssrn.3821950","url":null,"abstract":"Strengthening of TiAl-based intermetallic alloy is vital for its broader application, however, microstructural refinement through conventional processes is difficult to further strengthen this intermetallic alloy. Although high-density deformation nanotwin is expected to effectively strengthen it, there is still lack of in-depth understanding about the strengthening mechanism of high-density deformation nanotwin in TiAl-based alloy. Herein the microstructures, room-temperature (RT) tensile properties, tensile fracture behavior, and deformation mechanism of the Ti-45.5Al-4Cr-2.5Nb (at.%) master alloy (M. A.) as well as its continuous casting (C. C.) alloy and the heat-treated alloys were systematically investigated. After the C. C. alloy was annealed at 1250 °C for 2 hours, the volume fraction of (B2+γ) coupled structures in the original grains reached the minimum, the interlamellar spacing was markedly refined; besides, substantial Shockley partial dislocations and stacking faults were generated in γ phase. During RT tension, both the dominant deformation mechanisms of the M. A. and C. C. alloy were dislocation slip, while that of the 2h heat-treated alloy was changed into deformation twinning. High-density deformation nanotwins were generated in the γ phase (especially the γ lamellae) of the 2h heat-treated alloy, which improved the tensile strength of the M. A. by 79%. High-density deformation nanotwins can further strengthen TiAl-based alloy to a large extent, which is mainly attributed to the fact that their batch-to-batch generation in the polycrystalline TiAl-based alloy during tension could considerably relief the stress concentration in addition to effectively improving the work-hardening rate, thus making the work-hardening rate keeping stable.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"191 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79768183","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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