Biwen Yang, Bo Song, Liang Chen, Honghong Sun, Derek O. Northwood, Kristian E. Waters, Hao Ma
The desulfurization capacity of top slag in the process of pre-desulfurization of hot metal containing vanadium and titanium was researched. The top slag system of CaO-SiO2-MgO-Al2O3-TiO2-VOx that was formed by blast furnace slag and a CaO desulfurization agent reduced the sulfur in hot metal from 0.08 wt.% to 0.02 wt.%. It was found that the resulfurization of the slag happened in the later periods of the desulfurization process. The vanadium–titanium oxides were both acidic in the desulfurization slag. TiO2 and VOx reacted with the basic oxides to form CaTiO3 and MgV2O4 at 1623 K, which reduced free CaO and was not conducive to top slag desulfurization. The results of calculation showed that the top slag desulfurization accounted for 15% of the total desulfurization. Using the ionic and molecule coexistence theory of slag structure, it is shown that the desulfurization efficiency could be enhanced by adjusting both the amount of desulfurization agent and the composition of the blast furnace slag before pre-desulfurization.
研究了炉顶渣在含钒钛热金属预脱硫过程中的脱硫能力。由高炉炉渣和 CaO 脱硫剂形成的 CaO-SiO2-MgO-Al2O3-TiO2-VOx 炉顶渣系统可将热金属中的硫从 0.08 wt.% 降至 0.02 wt.%。研究发现，炉渣的再硫化发生在脱硫过程的后期。脱硫渣中的钒钛氧化物均呈酸性。TiO2 和 VOx 在 1623 K 时与碱性氧化物反应生成 CaTiO3 和 MgV2O4，使游离 CaO 减少，不利于炉顶渣脱硫。计算结果表明，顶渣脱硫占总脱硫量的 15%。利用炉渣结构的离子和分子共存理论，可以通过调整脱硫剂的用量和预脱硫前高炉炉渣的成分来提高脱硫效率。
{"title":"Influence of Top Slag Containing TiO2 and VOx on Hot Metal Pre-Desulfurization","authors":"Biwen Yang, Bo Song, Liang Chen, Honghong Sun, Derek O. Northwood, Kristian E. Waters, Hao Ma","doi":"10.3390/met14080910","DOIUrl":"https://doi.org/10.3390/met14080910","url":null,"abstract":"The desulfurization capacity of top slag in the process of pre-desulfurization of hot metal containing vanadium and titanium was researched. The top slag system of CaO-SiO2-MgO-Al2O3-TiO2-VOx that was formed by blast furnace slag and a CaO desulfurization agent reduced the sulfur in hot metal from 0.08 wt.% to 0.02 wt.%. It was found that the resulfurization of the slag happened in the later periods of the desulfurization process. The vanadium–titanium oxides were both acidic in the desulfurization slag. TiO2 and VOx reacted with the basic oxides to form CaTiO3 and MgV2O4 at 1623 K, which reduced free CaO and was not conducive to top slag desulfurization. The results of calculation showed that the top slag desulfurization accounted for 15% of the total desulfurization. Using the ionic and molecule coexistence theory of slag structure, it is shown that the desulfurization efficiency could be enhanced by adjusting both the amount of desulfurization agent and the composition of the blast furnace slag before pre-desulfurization.","PeriodicalId":18461,"journal":{"name":"Metals","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The corrosion behaviors of three bridge steels in a real tropical marine environment for 2 years were studied. One weathering steel (WS) was designed with higher levels of nickel, copper, and molybdenum compared to the other. These two kinds of WSs and one kind of ordinary high-strength low-alloy steel (Q345qe) were compared under two conditions (marine atmospheric zone and marine immersion zone at Sanya Marine Environmental Test Station). The morphology, corrosion rate, and corrosion product analysis of the steels were performed through SEM, XPS, FTIR and other characterization methods. The results demonstrated that weathering steels facilitate the densification of the corrosion product layer due to the addition of alloying elements Cr, Ni, and Cu, promoting rust nucleation and enhancing the compactness of the protective layer. However, in an immersion environment, the extensive erosion by chloride ions renders the benefits of WS ineffective.
{"title":"Corrosion Behaviors of Weathering Steels in the Actual Marine Atmospheric Zone and Immersion Zone","authors":"Ying Yang, Tianzi Lin, Guohui Wang, Yubo Wang, Minghui Shao, Fandi Meng, Fuhui Wang","doi":"10.3390/met14080903","DOIUrl":"https://doi.org/10.3390/met14080903","url":null,"abstract":"The corrosion behaviors of three bridge steels in a real tropical marine environment for 2 years were studied. One weathering steel (WS) was designed with higher levels of nickel, copper, and molybdenum compared to the other. These two kinds of WSs and one kind of ordinary high-strength low-alloy steel (Q345qe) were compared under two conditions (marine atmospheric zone and marine immersion zone at Sanya Marine Environmental Test Station). The morphology, corrosion rate, and corrosion product analysis of the steels were performed through SEM, XPS, FTIR and other characterization methods. The results demonstrated that weathering steels facilitate the densification of the corrosion product layer due to the addition of alloying elements Cr, Ni, and Cu, promoting rust nucleation and enhancing the compactness of the protective layer. However, in an immersion environment, the extensive erosion by chloride ions renders the benefits of WS ineffective.","PeriodicalId":18461,"journal":{"name":"Metals","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141923492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The TNM alloy, a βo-phase-containing TiAl alloy, has been withdrawn from use as a last-stage turbine blade in commercial jet engines as it suffered frequent impact fractures in service, raising doubts regarding the necessity of the βo-phase in practical TiAl alloys. Here, we evaluate the practical properties required for jet engine blades for various TiAl alloys and investigate the effects of the βo-phase thereupon. First, we explore the influence of the βo-phase content on the impact resistance and machinability for forged Ti–43.5Al–xCr and cast Ti–46.0Al–xCr alloys; the properties deteriorate significantly at increasing βo-phase contents. Subsequently, two practical TiAl alloys—TNM alloy and TiAl4822—were prepared with and without the βo-phase by varying the heat treatment temperature for the former and the Cr concentration for the latter. In addition to impact resistance and machinability, the creep strength is significantly reduced by the presence of the βo-phase. Overall, these findings suggest that the βo-phase is an undesirable phase in practical TiAl alloys, especially those used for jet engine blades, because, although the disordered β-phase is soft at high temperatures, it changes to significantly more brittle and harder βo-phase after cooling.
TNM 合金是一种含 βo- 相的 TiAl 合金，由于在使用中经常出现冲击断裂，已不再被用作商用喷气发动机的最后一级涡轮叶片，从而引发了人们对实用 TiAl 合金中是否需要 βo- 相的怀疑。在此，我们对喷气发动机叶片所需的各种 TiAl 合金的实际性能进行了评估，并研究了 βo- 相对其的影响。首先，我们探讨了β-相含量对锻造Ti-43.5Al-xCr和铸造Ti-46.0Al-xCr合金的抗冲击性和可加工性的影响；β-相含量增加时，合金的性能会明显降低。随后，通过改变前者的热处理温度和后者的铬浓度，制备了两种含有和不含β-相的实用TiAl合金--TNM合金和TiAl4822。除了抗冲击性和机加工性能外，蠕变强度也因 βo- 相的存在而显著降低。总之，这些研究结果表明，β-相是实用钛铝合金（尤其是用于喷气发动机叶片的钛铝合金）中不受欢迎的相，因为虽然无序的β-相在高温下很软，但冷却后会转变为明显更脆、更硬的β-相。
{"title":"Detrimental Effects of βo-Phase on Practical Properties of TiAl Alloys","authors":"Toshimitsu Tetsui, Kazuhiro Mizuta","doi":"10.3390/met14080908","DOIUrl":"https://doi.org/10.3390/met14080908","url":null,"abstract":"The TNM alloy, a βo-phase-containing TiAl alloy, has been withdrawn from use as a last-stage turbine blade in commercial jet engines as it suffered frequent impact fractures in service, raising doubts regarding the necessity of the βo-phase in practical TiAl alloys. Here, we evaluate the practical properties required for jet engine blades for various TiAl alloys and investigate the effects of the βo-phase thereupon. First, we explore the influence of the βo-phase content on the impact resistance and machinability for forged Ti–43.5Al–xCr and cast Ti–46.0Al–xCr alloys; the properties deteriorate significantly at increasing βo-phase contents. Subsequently, two practical TiAl alloys—TNM alloy and TiAl4822—were prepared with and without the βo-phase by varying the heat treatment temperature for the former and the Cr concentration for the latter. In addition to impact resistance and machinability, the creep strength is significantly reduced by the presence of the βo-phase. Overall, these findings suggest that the βo-phase is an undesirable phase in practical TiAl alloys, especially those used for jet engine blades, because, although the disordered β-phase is soft at high temperatures, it changes to significantly more brittle and harder βo-phase after cooling.","PeriodicalId":18461,"journal":{"name":"Metals","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kena Sun, Xiaowu Jie, Yonglu Zhang, Wei Gao, Derek O. Northwood, K. E. Waters, Hao Ma
Computational fluid dynamics (CFD) software was used to simulate the feeding behavior in a bottom-blown lead-smelting furnace. The results show that when the particle size is less than 30 μm, 20% of the particles are suspended in the gas phase and do not enter the melt pool for smelting, thus resulting in material loss. When the particle size exceeds 75 μm, the particles settle in the metal layer. When the particle size is 40–60 μm, the particles are distributed in the slag and metal phases, and the material is uniformly distributed in the molten pool; additionally, the average velocity of the particles exceeds 1.4 m/s, the average temperature exceeds 960 K, and the particles exhibit better behavior within this range, thus rendering it the optimal range of particle sizes for feeding.
{"title":"Analysis of the Feeding Behavior in a Bottom-Blown Lead-Smelting Furnace","authors":"Kena Sun, Xiaowu Jie, Yonglu Zhang, Wei Gao, Derek O. Northwood, K. E. Waters, Hao Ma","doi":"10.3390/met14080906","DOIUrl":"https://doi.org/10.3390/met14080906","url":null,"abstract":"Computational fluid dynamics (CFD) software was used to simulate the feeding behavior in a bottom-blown lead-smelting furnace. The results show that when the particle size is less than 30 μm, 20% of the particles are suspended in the gas phase and do not enter the melt pool for smelting, thus resulting in material loss. When the particle size exceeds 75 μm, the particles settle in the metal layer. When the particle size is 40–60 μm, the particles are distributed in the slag and metal phases, and the material is uniformly distributed in the molten pool; additionally, the average velocity of the particles exceeds 1.4 m/s, the average temperature exceeds 960 K, and the particles exhibit better behavior within this range, thus rendering it the optimal range of particle sizes for feeding.","PeriodicalId":18461,"journal":{"name":"Metals","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141922976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Kutyła, Michihisa Fukumoto, Hiroki Takahashi, M. Wojnicki, P. Żabiński
The presented paper characterized the molten salt-modified Ni electrode with excellent catalytic activity towards alkaline urea electrooxidation reaction. The electrodes were modified by electrodeposition of Al from molten salt electrolytes containing NaCl-KCl-AlF3 at a temperature of 750 °C and applied potential of −1.9 V. The porous surface was obtained by anodic polarization with a potential of −0.4 V until the anodic current was equal to 0 mAcm−2. The prepared deposits’ structure, surface morphology, and composition were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Anodic polarization was applied to assess the electrocatalytic activity and elucidate the urea electrooxidation mechanism in 1 M KOH + 0.33 M urea solution. The nanocrystalline structure, fine grain size, and microcracks on the surface of the studied electrodes contributed to their notably high electrochemically active surface area (ECSA). The cyclic voltammetry in the non-Faradaic regions of the samples shows that molten salt modification can increase the double layer capacitance of bare Ni plates by around ten times, from 0.29 mFcm−2 to 2.16 mFcm−2. Polarization of the electrodes in urea-containing KOH solution with potential of +1.52 V shows a significant difference in catalytic performance. For the bare nickel sample, the registered current density from the urea electrooxidation reaction was around +1 mAcm−2, and for the molten salt-modified one, it was +38 mAcm−2, which indicates the fact that the molten salt surface treatment can be a promising tool in tailoring the electrochemical properties of materials.
本文介绍了对碱性尿素电氧化反应具有优异催化活性的熔盐改性镍电极。电极的改性是通过从含有 NaCl-KCl-AlF3 的熔盐电解液中电沉积铝来实现的，电沉积温度为 750 °C，施加电位为 -1.9 V。使用扫描电子显微镜（SEM）和 X 射线衍射（XRD）分析了所制备沉积物的结构、表面形态和成分。在 1 M KOH + 0.33 M 尿素溶液中，采用阳极极化法评估电催化活性并阐明尿素电氧化机制。所研究电极的纳米晶体结构、细晶粒度和表面微裂纹使其具有显著的高电化学活性表面积（ECSA）。样品非法拉第区的循环伏安法显示，熔盐改性可将裸镍板的双层电容提高约十倍，从 0.29 mFcm-2 提高到 2.16 mFcm-2。在电位为 +1.52 V 的含尿素 KOH 溶液中对电极进行极化，结果显示催化性能存在显著差异。对于裸镍样品，尿素电氧化反应产生的记录电流密度约为 +1 mAcm-2，而对于熔盐修饰的样品，则为 +38 mAcm-2，这表明熔盐表面处理是一种很有前途的定制材料电化学特性的工具。
{"title":"Catalytic Activity Evaluation of the Molten Salt-Modified Novel Ni Electrodes for Urea Electrooxidation in Alkaline Solutions","authors":"D. Kutyła, Michihisa Fukumoto, Hiroki Takahashi, M. Wojnicki, P. Żabiński","doi":"10.3390/met14080904","DOIUrl":"https://doi.org/10.3390/met14080904","url":null,"abstract":"The presented paper characterized the molten salt-modified Ni electrode with excellent catalytic activity towards alkaline urea electrooxidation reaction. The electrodes were modified by electrodeposition of Al from molten salt electrolytes containing NaCl-KCl-AlF3 at a temperature of 750 °C and applied potential of −1.9 V. The porous surface was obtained by anodic polarization with a potential of −0.4 V until the anodic current was equal to 0 mAcm−2. The prepared deposits’ structure, surface morphology, and composition were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Anodic polarization was applied to assess the electrocatalytic activity and elucidate the urea electrooxidation mechanism in 1 M KOH + 0.33 M urea solution. The nanocrystalline structure, fine grain size, and microcracks on the surface of the studied electrodes contributed to their notably high electrochemically active surface area (ECSA). The cyclic voltammetry in the non-Faradaic regions of the samples shows that molten salt modification can increase the double layer capacitance of bare Ni plates by around ten times, from 0.29 mFcm−2 to 2.16 mFcm−2. Polarization of the electrodes in urea-containing KOH solution with potential of +1.52 V shows a significant difference in catalytic performance. For the bare nickel sample, the registered current density from the urea electrooxidation reaction was around +1 mAcm−2, and for the molten salt-modified one, it was +38 mAcm−2, which indicates the fact that the molten salt surface treatment can be a promising tool in tailoring the electrochemical properties of materials.","PeriodicalId":18461,"journal":{"name":"Metals","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141922184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Inclusions are an important parameter affecting the fatigue life of materials. In this paper, the type, size, and quantity of inclusions in bearing steel were quantitatively analyzed using scanning electron microscopy and automatic scanning electron microscopy with an X-ray energy dispersive spectroscopy function. The effects of the inclusion parameters and positions on the rotating bending fatigue properties were analyzed using the rotating bending fatigue test. The results proved that for samples 1 and 2, the inclusions were mainly sulfides, Ti-containing inclusions, and their composite inclusions. For samples 3 and 4, the inclusions were mainly oxides or sulfide–oxide complexes. The number and maximum size of inclusions in sample 2 were relatively small. This was mainly due to the difference in the content of Al, S, and Ca elements in the different samples. The inclusion distance to the surface and the maximum inclusion size had a larger influence on the rotating bending fatigue life in comparison to the inclusion type. Moreover, nitride–oxides had a more detrimental effect on the rotating bending fatigue life as compared to the sulfide–oxide complex inclusions. A model was established on the basis of the inclusion size, depth, and stress by using the Python software. The simulation demonstrated that using five parameters fit well with the experiment results.
夹杂物是影响材料疲劳寿命的一个重要参数。本文利用扫描电子显微镜和带 X 射线能量色散光谱功能的自动扫描电子显微镜对轴承钢中夹杂物的类型、尺寸和数量进行了定量分析。利用旋转弯曲疲劳试验分析了夹杂物参数和位置对旋转弯曲疲劳性能的影响。结果证明，对于样品 1 和 2，夹杂物主要是硫化物、含钛夹杂物及其复合夹杂物。对于样品 3 和 4，夹杂物主要是氧化物或硫化物-氧化物复合物。样品 2 中夹杂物的数量和最大尺寸相对较小。这主要是由于不同样品中 Al、S 和 Ca 元素的含量不同。与夹杂物类型相比，夹杂物到表面的距离和最大夹杂物尺寸对旋转弯曲疲劳寿命的影响更大。此外，与硫化物-氧化物复合夹杂物相比，氮化物-氧化物对旋转弯曲疲劳寿命的影响更大。根据夹杂物的尺寸、深度和应力，利用 Python 软件建立了一个模型。模拟结果表明，使用五个参数与实验结果非常吻合。
{"title":"Influence of Inclusion Parameter and Depth on the Rotating Bending Fatigue Behavior of Bearing Steel","authors":"Lijun Xu, Zhonghua Zhan, Shulan Zhang","doi":"10.3390/met14080907","DOIUrl":"https://doi.org/10.3390/met14080907","url":null,"abstract":"Inclusions are an important parameter affecting the fatigue life of materials. In this paper, the type, size, and quantity of inclusions in bearing steel were quantitatively analyzed using scanning electron microscopy and automatic scanning electron microscopy with an X-ray energy dispersive spectroscopy function. The effects of the inclusion parameters and positions on the rotating bending fatigue properties were analyzed using the rotating bending fatigue test. The results proved that for samples 1 and 2, the inclusions were mainly sulfides, Ti-containing inclusions, and their composite inclusions. For samples 3 and 4, the inclusions were mainly oxides or sulfide–oxide complexes. The number and maximum size of inclusions in sample 2 were relatively small. This was mainly due to the difference in the content of Al, S, and Ca elements in the different samples. The inclusion distance to the surface and the maximum inclusion size had a larger influence on the rotating bending fatigue life in comparison to the inclusion type. Moreover, nitride–oxides had a more detrimental effect on the rotating bending fatigue life as compared to the sulfide–oxide complex inclusions. A model was established on the basis of the inclusion size, depth, and stress by using the Python software. The simulation demonstrated that using five parameters fit well with the experiment results.","PeriodicalId":18461,"journal":{"name":"Metals","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stephen Price, Kiran Judd, Matthew Gleason, Kyle Tsaknopoulos, D. Cote, Rodica Neamtu
Wire arc-directed energy deposit (wire-arc DED) enables the efficient manufacturing of large-scale metal parts. Many factors can impact overall part quality during manufacturing, including processing parameters such as feed rate, travel speed, and various material properties. Previous works have sought to use machine learning to evaluate and predict these impacts, but they have primarily focused on the width and height of single-layer deposits. Building upon these studies, this work offers a novel technique to characterize and evaluate the asymmetry of deposited beads to better understand the impact these parameters have. Specifically, leveraging time-series analysis techniques, the surface profiles of beads can be compared and analyzed to identify the degree of asymmetry. Additionally, this work relates these factors to the extent to which substrates warp during the depositing of material. With a better understanding of these impacts, manufacturing processes can be optimized for improved quality and reduced waste. These findings highlight that, while material selection and processing parameters do not strongly correlate with bead asymmetry, beads are deposited with varying degrees of asymmetry, requiring further analysis to identify the source. In contrast, substrate warping is significantly influenced by the thermal properties of the materials used. Of the properties analyzed, heat capacity, thermal diffusivity and thermal conductivity were found to be most relevant to substrate warping. Additionally, while to a lesser extent, material properties of the wire were found to be similarly correlated to warping as their substrate counterparts. These insights can inform the optimization of manufacturing processes, leading to improved part quality and reduced material waste. This study also underscores the need for further research into the interplay between processing conditions and material characteristics in wire-arc DED.
{"title":"Analyzing Impact of Processing Parameters and Material Properties on Symmetry of Wire-Arc Directed Energy Deposit Beads","authors":"Stephen Price, Kiran Judd, Matthew Gleason, Kyle Tsaknopoulos, D. Cote, Rodica Neamtu","doi":"10.3390/met14080905","DOIUrl":"https://doi.org/10.3390/met14080905","url":null,"abstract":"Wire arc-directed energy deposit (wire-arc DED) enables the efficient manufacturing of large-scale metal parts. Many factors can impact overall part quality during manufacturing, including processing parameters such as feed rate, travel speed, and various material properties. Previous works have sought to use machine learning to evaluate and predict these impacts, but they have primarily focused on the width and height of single-layer deposits. Building upon these studies, this work offers a novel technique to characterize and evaluate the asymmetry of deposited beads to better understand the impact these parameters have. Specifically, leveraging time-series analysis techniques, the surface profiles of beads can be compared and analyzed to identify the degree of asymmetry. Additionally, this work relates these factors to the extent to which substrates warp during the depositing of material. With a better understanding of these impacts, manufacturing processes can be optimized for improved quality and reduced waste. These findings highlight that, while material selection and processing parameters do not strongly correlate with bead asymmetry, beads are deposited with varying degrees of asymmetry, requiring further analysis to identify the source. In contrast, substrate warping is significantly influenced by the thermal properties of the materials used. Of the properties analyzed, heat capacity, thermal diffusivity and thermal conductivity were found to be most relevant to substrate warping. Additionally, while to a lesser extent, material properties of the wire were found to be similarly correlated to warping as their substrate counterparts. These insights can inform the optimization of manufacturing processes, leading to improved part quality and reduced material waste. This study also underscores the need for further research into the interplay between processing conditions and material characteristics in wire-arc DED.","PeriodicalId":18461,"journal":{"name":"Metals","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141924997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The materials used in concentrating solar power (CSP) systems are becoming of interest because of the high energy efficiency of energy storage. Molten salts can be used as both heat-storage media and heat-transfer fluid in a CSP system. In molten salts, steel alloys used in vessels and pipelines are highly vulnerable to hot corrosion. To protect steel alloys, applying a coating is an excellent strategy to extend the life of the alloy. NiCrAl coatings are well-suited for high-temperature environments. The purpose of this study was to investigate the corrosion behavior of NiCrAl with Si addition coatings on AISI304 in molten salt. NiCrAl coatings with and without Si addition were deposited using the high-velocity oxygen fuel (HVOF) technique. The corrosion test was performed using an immersion test in modified solar salt with 0.5% NaCl at 400–600 °C. Gravimetric methods evaluate the weight change for immersion tests. At 400 °C, an increased amount of weight gain due to the oxidation reaction and molten salt infiltration was observed. At 600 °C, the corrosion reaction was more dominant, and apparent oxidation was decreased; however, oxidation products NiO and sodium aluminum silicate were detected. Si addition supports the formation of the protective oxide sodium aluminum silicate, which inhibits molten salt oxidation reaction and molten salt infiltration.
{"title":"Effect of Si Addition in NiCrAl Coating on Corrosion in Molten Nitrate Salt","authors":"Thamrongsin Siripongsakul, Patchaporn Kettrakul, Noparat Kanjanaprayut, Piyorose Promdirek","doi":"10.3390/met14080902","DOIUrl":"https://doi.org/10.3390/met14080902","url":null,"abstract":"The materials used in concentrating solar power (CSP) systems are becoming of interest because of the high energy efficiency of energy storage. Molten salts can be used as both heat-storage media and heat-transfer fluid in a CSP system. In molten salts, steel alloys used in vessels and pipelines are highly vulnerable to hot corrosion. To protect steel alloys, applying a coating is an excellent strategy to extend the life of the alloy. NiCrAl coatings are well-suited for high-temperature environments. The purpose of this study was to investigate the corrosion behavior of NiCrAl with Si addition coatings on AISI304 in molten salt. NiCrAl coatings with and without Si addition were deposited using the high-velocity oxygen fuel (HVOF) technique. The corrosion test was performed using an immersion test in modified solar salt with 0.5% NaCl at 400–600 °C. Gravimetric methods evaluate the weight change for immersion tests. At 400 °C, an increased amount of weight gain due to the oxidation reaction and molten salt infiltration was observed. At 600 °C, the corrosion reaction was more dominant, and apparent oxidation was decreased; however, oxidation products NiO and sodium aluminum silicate were detected. Si addition supports the formation of the protective oxide sodium aluminum silicate, which inhibits molten salt oxidation reaction and molten salt infiltration.","PeriodicalId":18461,"journal":{"name":"Metals","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diangeng Cai, Jiayu Wang, Lei Yang, Xiaocen Xu, Erlin Zhang
Ti-13Nb-13Zr-7Ag (TNZ-7Ag) has a great potential for biomedical application due to its low elastic modulus and excellent antibacterial properties. However, it is difficult to balance low elastic modulus and high antibacterial properties. In this study, the TNZ-7Ag was treated by a pre-deformation and aging treatment to avoid this problem. The results proved that the stress-induced twinning caused a large range of Ti2Ag particle agglomeration, and in turn enhanced the antibacterial performance of Ag-containing titanium alloys. And the twinned martensite formed during the pre-deformation promoted the precipitation of Ti2Ag phase and inhibited the growth of α phase. As a result, TNZ-7Ag with both low elastic modulus and strong antibacterial properties was obtained by the treatments. All results demonstrated that pre-deformation based on the synergistic effect of aging treatment was an effective strategy to develop novel biomedical titanium alloys. Low-elastic-modulus antibacterial titanium alloys, which can be used for the development of novel biomedical titanium alloys, were prepared.
{"title":"Synergistic Effect of Phase Transformation and Stress-Induced Twinning on the Antibacterial Property and Elastic Modulus of Ti-13Nb-13Zr-7Ag","authors":"Diangeng Cai, Jiayu Wang, Lei Yang, Xiaocen Xu, Erlin Zhang","doi":"10.3390/met14080901","DOIUrl":"https://doi.org/10.3390/met14080901","url":null,"abstract":"Ti-13Nb-13Zr-7Ag (TNZ-7Ag) has a great potential for biomedical application due to its low elastic modulus and excellent antibacterial properties. However, it is difficult to balance low elastic modulus and high antibacterial properties. In this study, the TNZ-7Ag was treated by a pre-deformation and aging treatment to avoid this problem. The results proved that the stress-induced twinning caused a large range of Ti2Ag particle agglomeration, and in turn enhanced the antibacterial performance of Ag-containing titanium alloys. And the twinned martensite formed during the pre-deformation promoted the precipitation of Ti2Ag phase and inhibited the growth of α phase. As a result, TNZ-7Ag with both low elastic modulus and strong antibacterial properties was obtained by the treatments. All results demonstrated that pre-deformation based on the synergistic effect of aging treatment was an effective strategy to develop novel biomedical titanium alloys. Low-elastic-modulus antibacterial titanium alloys, which can be used for the development of novel biomedical titanium alloys, were prepared.","PeriodicalId":18461,"journal":{"name":"Metals","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141927577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sergiy Bogatyrenko, Pavlo Kryshtal, Adam Gruszczyński, A. Kryshtal
We investigated the mechanism and kinetics of the formation of metastable BiGe solid phases during the amorphous-to-crystalline transformation of Ge films in contact with Bi. Ge/Bi/Ge sandwich films with a Bi film between amorphous Ge films, which were fabricated by sequential deposition of the components in a vacuum, were used in this study. The total thickness and composition of the sandwich films varied in the range from 30 to 400 nm and from 22 to 48 wt% Bi, respectively. Electron diffraction, high-resolution (S)TEM imaging, EDX, and EEL spectroscopy were used for in situ and ex situ characterization of the morphology, composition, and structure of Ge/Bi/Ge films in the temperature range of 20–271 °C. We proved the formation of polycrystalline Ge films containing up to 28 wt% Bi during low-temperature treatment. The interaction process was activated at ≈150 °C, resulting in the crystallization of Ge with the simultaneous formation of a quasi-homogeneous supersaturated solid solution throughout the entire volume of the film at ≈210 °C. We showed that the formation of crystalline Ge films with an extended solid solubility of Bi depended mostly on the overall composition of the tri-layer film. The role of metal-induced crystallization of the amorphous germanium in the formation of the supersaturated solid phases is discussed.
我们研究了与 Bi 接触的 Ge 薄膜从非晶到晶体转变过程中形成可蜕变 BiGe 固相的机制和动力学。本研究采用了在无定形 Ge 薄膜之间夹有一层 Bi 薄膜的 Ge/Bi/Ge 夹层薄膜，这些薄膜是通过在真空中依次沉积各组分而制成的。夹层薄膜的总厚度和成分变化范围分别为 30 至 400 nm 和 22 至 48 wt% Bi。我们使用电子衍射、高分辨率 (S)TEM 成像、EDX 和 EEL 光谱对 20-271 ℃ 温度范围内的 Ge/Bi/Ge 薄膜的形态、成分和结构进行了原位和非原位表征。我们证明了在低温处理过程中形成了含铋高达 28 wt% 的多晶 Ge 薄膜。相互作用过程在温度≈150 °C时被激活，导致Ge结晶，同时在温度≈210 °C时在薄膜的整个体积中形成准均质过饱和固溶体。我们的研究表明，结晶 Ge 薄膜的形成与 Bi 固溶性的扩展主要取决于三层薄膜的整体组成。我们讨论了金属诱导无定形锗结晶在形成过饱和固相中的作用。
{"title":"Formation of Metastable Solid Solutions in Bi-Ge Films during Low-Temperature Treatment","authors":"Sergiy Bogatyrenko, Pavlo Kryshtal, Adam Gruszczyński, A. Kryshtal","doi":"10.3390/met14080900","DOIUrl":"https://doi.org/10.3390/met14080900","url":null,"abstract":"We investigated the mechanism and kinetics of the formation of metastable BiGe solid phases during the amorphous-to-crystalline transformation of Ge films in contact with Bi. Ge/Bi/Ge sandwich films with a Bi film between amorphous Ge films, which were fabricated by sequential deposition of the components in a vacuum, were used in this study. The total thickness and composition of the sandwich films varied in the range from 30 to 400 nm and from 22 to 48 wt% Bi, respectively. Electron diffraction, high-resolution (S)TEM imaging, EDX, and EEL spectroscopy were used for in situ and ex situ characterization of the morphology, composition, and structure of Ge/Bi/Ge films in the temperature range of 20–271 °C. We proved the formation of polycrystalline Ge films containing up to 28 wt% Bi during low-temperature treatment. The interaction process was activated at ≈150 °C, resulting in the crystallization of Ge with the simultaneous formation of a quasi-homogeneous supersaturated solid solution throughout the entire volume of the film at ≈210 °C. We showed that the formation of crystalline Ge films with an extended solid solubility of Bi depended mostly on the overall composition of the tri-layer film. The role of metal-induced crystallization of the amorphous germanium in the formation of the supersaturated solid phases is discussed.","PeriodicalId":18461,"journal":{"name":"Metals","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141926223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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