Ti-Cr-V-based alloys have been utilized across various domains, including aerospace structural and functional materials and hydrogen storage materials. Investigating the phase relations in the Ti-Cr-V system is significant in supporting the material design for these applications. In the present work, the isothermal sections at 1000, 1100, and 1200 °C for the Ti-Cr-V system were precisely determined through a systematic investigation using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The phase region of Cr2Ti was entirely elucidated for the first time. As the temperature decreased from 1200 to 1000 °C, the V solubility range of Cr2Ti increased from 5.3 wt.% to 10.0 wt.%, while the Ti solubility range essentially remained constant at approximately 31.0–33.9 wt.%. In addition, it was suggested that the stable structure of Cr2Ti was C36 at 1200 °C and C15 at 1000 and 1100 °C. The present work will support thermodynamic re-assessment research.
基于 Ti-Cr-V 的合金已被广泛应用于各个领域，包括航空航天结构和功能材料以及储氢材料。研究 Ti-Cr-V 系统中的相关系对于支持这些应用的材料设计具有重要意义。在本研究中，通过使用扫描电子显微镜（SEM）、能量色散 X 射线光谱（EDS）和 X 射线衍射（XRD）进行系统研究，精确测定了 Ti-Cr-V 系统在 1000、1100 和 1200 ℃ 下的等温截面。首次完全阐明了 Cr2Ti 的相区。随着温度从 1200 ℃ 降到 1000 ℃，Cr2Ti 的 V 溶解度范围从 5.3 wt.% 增加到 10.0 wt.%，而 Ti 溶解度范围基本保持不变，约为 31.0-33.9 wt.%。此外，研究表明 Cr2Ti 的稳定结构在 1200 °C 时为 C36，在 1000 和 1100 °C 时为 C15。本研究将为热力学再评估研究提供支持。
{"title":"Experimental Investigation of Phase Equilibria in the Ti-Cr-V System at 1000–1200 °C","authors":"Shiyu Fu, Jing-jing Wang, Xiao-Gang Lu","doi":"10.3390/met14050498","DOIUrl":"https://doi.org/10.3390/met14050498","url":null,"abstract":"Ti-Cr-V-based alloys have been utilized across various domains, including aerospace structural and functional materials and hydrogen storage materials. Investigating the phase relations in the Ti-Cr-V system is significant in supporting the material design for these applications. In the present work, the isothermal sections at 1000, 1100, and 1200 °C for the Ti-Cr-V system were precisely determined through a systematic investigation using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The phase region of Cr2Ti was entirely elucidated for the first time. As the temperature decreased from 1200 to 1000 °C, the V solubility range of Cr2Ti increased from 5.3 wt.% to 10.0 wt.%, while the Ti solubility range essentially remained constant at approximately 31.0–33.9 wt.%. In addition, it was suggested that the stable structure of Cr2Ti was C36 at 1200 °C and C15 at 1000 and 1100 °C. The present work will support thermodynamic re-assessment research.","PeriodicalId":510812,"journal":{"name":"Metals","volume":"90 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140654815","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}
The steel industry is an important foundation of the national economy and the livelihood of the people, producing a large amount of carbon dioxide gas, accounting for about 70% of the carbon dioxide gas generated in the steel industry, which occurs during the ironmaking process. Therefore, the key technology to reduce the pollution and improve competitiveness is to increase the stability of blast furnace production and the quality of hot metal. Since the operation requirements for temperature control in the vanadium-titanium blast furnace are dramatically different compared to the traditional ones due to the low fluidity of vanadium-titanium slag, maintaining the required hot metal temperature within a narrow range with smaller fluctuations is essential. In addition, the adjustment parameters of the lower part have a significant influence on the tuyere combustion flame temperature during the daily operation of blast furnaces. At present, there is no relevant research on the online detection and analysis of vanadium-titanium blast furnace tuyere combustion flame temperature. In this study, the temperature of four tuyeres in a 500 m3 vanadium and titanium blast furnace at Jianlong Steel was detected by an online detection system. The tuyere combustion flame temperature was then calculated using colorimetric temperature measuring methodology at various times and at four distinct locations. After that, the calibration analyses, imaging parameter and the temperature tendencies in different directions of the blast furnace were investigated. This study not only offers new methods for understanding the regularity of operation and increasing the degree of visualization in vanadium and titanium smelting blast furnaces but also provides technical support for intelligent and low-carbon operation in blast furnaces.
{"title":"Study of Tuyere Combustion Flame Temperature in Vanadium and Titanium Blast Furnaces by Machine Vision and Colorimetric Thermometry","authors":"Haoyu Cai, Ziming Zhu, Dongdong Zhou","doi":"10.3390/met14050499","DOIUrl":"https://doi.org/10.3390/met14050499","url":null,"abstract":"The steel industry is an important foundation of the national economy and the livelihood of the people, producing a large amount of carbon dioxide gas, accounting for about 70% of the carbon dioxide gas generated in the steel industry, which occurs during the ironmaking process. Therefore, the key technology to reduce the pollution and improve competitiveness is to increase the stability of blast furnace production and the quality of hot metal. Since the operation requirements for temperature control in the vanadium-titanium blast furnace are dramatically different compared to the traditional ones due to the low fluidity of vanadium-titanium slag, maintaining the required hot metal temperature within a narrow range with smaller fluctuations is essential. In addition, the adjustment parameters of the lower part have a significant influence on the tuyere combustion flame temperature during the daily operation of blast furnaces. At present, there is no relevant research on the online detection and analysis of vanadium-titanium blast furnace tuyere combustion flame temperature. In this study, the temperature of four tuyeres in a 500 m3 vanadium and titanium blast furnace at Jianlong Steel was detected by an online detection system. The tuyere combustion flame temperature was then calculated using colorimetric temperature measuring methodology at various times and at four distinct locations. After that, the calibration analyses, imaging parameter and the temperature tendencies in different directions of the blast furnace were investigated. This study not only offers new methods for understanding the regularity of operation and increasing the degree of visualization in vanadium and titanium smelting blast furnaces but also provides technical support for intelligent and low-carbon operation in blast furnaces.","PeriodicalId":510812,"journal":{"name":"Metals","volume":"18 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140656226","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}
T. Pickle, Yu Hong, Chad Augustine, Judith Vidal, Zhenzhen Yu
Stress relaxation cracking (SRC) is considered one of the major failure mechanisms for 347H stainless steel welds at elevated service temperatures or during post weld heat treatment (PWHT), especially within the heat-affected zone (HAZ). This work focuses on the characterization of SRC susceptibility within 347H physically simulated arc welded HAZ at elevated temperatures. A four-step SRC thermomechanical test in combination with finite element modeling (FEM) of the welding and testing processes is developed to establish a susceptibility map for HAZ. The test first runs a thermal cycle with three different peak temperatures (1335, 1275, and 1150 °C) to duplicate representative HAZ subzone microstructures, followed by time-to-failure examination under a variety of pre-stress (260–600 MPa) and pre-strain conditions (0.03–0.19) as a function of reheat temperatures between 750 and 1050 °C. With the aid of FEM, SRC susceptibility maps are generated to identify the threshold stress, plastic strain, and creep strain as a function of test temperature. It was found out that HAZ subzone with a lower peak temperature (1150 °C) appears to be slightly less susceptible to SRC than the other two subzones that experienced higher peak temperatures. Generally, time-to-fracture reduces with increasing initially applied stress and strain for all test temperatures. The pre-stress thresholds decrease from about 500 to 330 MPa as the testing temperature increases from 800 to 1050 °C, while the corresponding initial plastic strain thresholds reduces from 0.15 to 0.06. The SRC susceptibility was also evaluated through the Larson–Miller Parameter (LMP) analysis as a function of plastic strain, initial stress and starting stress upon reaching the testing temperature, respectively. The 1050 °C test with a high pre-applied strain (0.1) exhibits an extremely short time to failure (t = 3 s) that lies outside the general trend in LMP analysis. Additionally, it was identified that a plastic strain above 0.07 is identified to significantly reduce the bulk creep strain tolerance to fracture and therefore increases SRC susceptibility. Hardness measurement and fractography analysis indicated that the strain aging of niobium carbonitrides and other potential phases in conjunction with intergranular precipitates contributes to an increase in microhardness and increased intergranular cracking susceptibility.
{"title":"Stress Relaxation Cracking in 347H Stainless Steel Arc Welds: Susceptibility Evaluation of Heat-Affected Zone","authors":"T. Pickle, Yu Hong, Chad Augustine, Judith Vidal, Zhenzhen Yu","doi":"10.3390/met14050494","DOIUrl":"https://doi.org/10.3390/met14050494","url":null,"abstract":"Stress relaxation cracking (SRC) is considered one of the major failure mechanisms for 347H stainless steel welds at elevated service temperatures or during post weld heat treatment (PWHT), especially within the heat-affected zone (HAZ). This work focuses on the characterization of SRC susceptibility within 347H physically simulated arc welded HAZ at elevated temperatures. A four-step SRC thermomechanical test in combination with finite element modeling (FEM) of the welding and testing processes is developed to establish a susceptibility map for HAZ. The test first runs a thermal cycle with three different peak temperatures (1335, 1275, and 1150 °C) to duplicate representative HAZ subzone microstructures, followed by time-to-failure examination under a variety of pre-stress (260–600 MPa) and pre-strain conditions (0.03–0.19) as a function of reheat temperatures between 750 and 1050 °C. With the aid of FEM, SRC susceptibility maps are generated to identify the threshold stress, plastic strain, and creep strain as a function of test temperature. It was found out that HAZ subzone with a lower peak temperature (1150 °C) appears to be slightly less susceptible to SRC than the other two subzones that experienced higher peak temperatures. Generally, time-to-fracture reduces with increasing initially applied stress and strain for all test temperatures. The pre-stress thresholds decrease from about 500 to 330 MPa as the testing temperature increases from 800 to 1050 °C, while the corresponding initial plastic strain thresholds reduces from 0.15 to 0.06. The SRC susceptibility was also evaluated through the Larson–Miller Parameter (LMP) analysis as a function of plastic strain, initial stress and starting stress upon reaching the testing temperature, respectively. The 1050 °C test with a high pre-applied strain (0.1) exhibits an extremely short time to failure (t = 3 s) that lies outside the general trend in LMP analysis. Additionally, it was identified that a plastic strain above 0.07 is identified to significantly reduce the bulk creep strain tolerance to fracture and therefore increases SRC susceptibility. Hardness measurement and fractography analysis indicated that the strain aging of niobium carbonitrides and other potential phases in conjunction with intergranular precipitates contributes to an increase in microhardness and increased intergranular cracking susceptibility.","PeriodicalId":510812,"journal":{"name":"Metals","volume":"55 44","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140661943","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}
In this study, the synergistic behavior of Ni and Al in two low-density steels (Fe-26Mn-10.2Al-0.98C-0.15V (wt. %) and Fe-29Mn-5Al-1C-12Ni (wt. %)) and their influence on microstructures and mechanical properties were investigated. The chemical composition of κ-carbides and B2 precipitated particles as a function of annealing and aging temperature and the matrix within which they formed were elucidated. The microstructures and deformation mechanisms of both steels were studied based on their strengthening contribution. The Fe-26Mn-10.2Al-0.98C-0.15V steel mainly realized precipitation strengthening through κ-carbides and grain boundary strengthening due to full recrystallization. The strengthening caused by Fe-29Mn-5Al-1C-12Ni steel was mainly due to the presence of the B2 phase in the matrix, which was non-coherent with FCC. This led to the Orowan bypass mechanism, which made precipitation strengthening the main strengthening contribution. The synergistic effect led to the shear or bypass mechanism of both steels when plane dislocation slip occurred. In addition, it also had an influence on the work-hardening capability during plastic deformation. This study provides a promising way to further enhance the yield strength of low-density austenitic steels through the synergistic effect of Ni and Al.
{"title":"Synergistic Effect of Al and Ni on Microstructure Evolutions and Mechanical Properties of Fe-Mn-Al-C Low-Density Steels","authors":"Xiaodong Lv, Xuejiao Wang, Aidong Lan, J. Qiao","doi":"10.3390/met14050495","DOIUrl":"https://doi.org/10.3390/met14050495","url":null,"abstract":"In this study, the synergistic behavior of Ni and Al in two low-density steels (Fe-26Mn-10.2Al-0.98C-0.15V (wt. %) and Fe-29Mn-5Al-1C-12Ni (wt. %)) and their influence on microstructures and mechanical properties were investigated. The chemical composition of κ-carbides and B2 precipitated particles as a function of annealing and aging temperature and the matrix within which they formed were elucidated. The microstructures and deformation mechanisms of both steels were studied based on their strengthening contribution. The Fe-26Mn-10.2Al-0.98C-0.15V steel mainly realized precipitation strengthening through κ-carbides and grain boundary strengthening due to full recrystallization. The strengthening caused by Fe-29Mn-5Al-1C-12Ni steel was mainly due to the presence of the B2 phase in the matrix, which was non-coherent with FCC. This led to the Orowan bypass mechanism, which made precipitation strengthening the main strengthening contribution. The synergistic effect led to the shear or bypass mechanism of both steels when plane dislocation slip occurred. In addition, it also had an influence on the work-hardening capability during plastic deformation. This study provides a promising way to further enhance the yield strength of low-density austenitic steels through the synergistic effect of Ni and Al.","PeriodicalId":510812,"journal":{"name":"Metals","volume":"53 25","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140661974","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}
Anatoly Illarionov, Galymzhan Mukanov, Stepan I Stepanov, Viktor Kuznetsov, R. Karelin, Vladimir Andreev, Vladimir Yusupov, Andrei Korelin
The evolution of microstructure, phase composition and physico-mechanical properties of the biocompatible Ti-39Nb-7Zr alloy (wt.%) after severe plastic deformation by rotary forging (RF) was studied using various methods including light optical microscopy, scanning and transmission electron microscopies, X-ray diffraction, microindentation, tensile testing and investigation of thermophysical properties during continuous heating. The hot-rolled Ti-39Nb-7Zr with initial single β-phase structure is subjected to multi-pass RF at 450 °C with an accumulated degree of true deformation of 1.2, resulting in the formation of a fibrous β-grain structure with imperfect 500 nm subgrains characterized by an increased dislocation density. Additionally, nano-sized α-precipitates formed in the body and along the β-grain boundaries. These structural changes resulted in an increase in microhardness from 215 HV to 280 HV and contact modulus of elasticity from 70 GPa to 76 GPa. The combination of strength and ductility of Ti-39Nb-7Zr after RF approaches that of the widely used Ti-6Al-4V ELI alloy in medicine, however, Ti-39Nb-7Zr does not contain elements with limited biocompatibility and has a modulus of elasticity 1.5 times lower than Ti-6Al-4V ELI. The temperature dependences of physical properties (elastic modulus, heat capacity, thermal diffusivity) of the Ti-39Nb-7Zr alloy after RF are considered and sufficient thermal stability of the alloy up to 450 °C is demonstrated.
{"title":"Microstructure and Physico-Mechanical Properties of Biocompatible Titanium Alloy Ti-39Nb-7Zr after Rotary Forging","authors":"Anatoly Illarionov, Galymzhan Mukanov, Stepan I Stepanov, Viktor Kuznetsov, R. Karelin, Vladimir Andreev, Vladimir Yusupov, Andrei Korelin","doi":"10.3390/met14050497","DOIUrl":"https://doi.org/10.3390/met14050497","url":null,"abstract":"The evolution of microstructure, phase composition and physico-mechanical properties of the biocompatible Ti-39Nb-7Zr alloy (wt.%) after severe plastic deformation by rotary forging (RF) was studied using various methods including light optical microscopy, scanning and transmission electron microscopies, X-ray diffraction, microindentation, tensile testing and investigation of thermophysical properties during continuous heating. The hot-rolled Ti-39Nb-7Zr with initial single β-phase structure is subjected to multi-pass RF at 450 °C with an accumulated degree of true deformation of 1.2, resulting in the formation of a fibrous β-grain structure with imperfect 500 nm subgrains characterized by an increased dislocation density. Additionally, nano-sized α-precipitates formed in the body and along the β-grain boundaries. These structural changes resulted in an increase in microhardness from 215 HV to 280 HV and contact modulus of elasticity from 70 GPa to 76 GPa. The combination of strength and ductility of Ti-39Nb-7Zr after RF approaches that of the widely used Ti-6Al-4V ELI alloy in medicine, however, Ti-39Nb-7Zr does not contain elements with limited biocompatibility and has a modulus of elasticity 1.5 times lower than Ti-6Al-4V ELI. The temperature dependences of physical properties (elastic modulus, heat capacity, thermal diffusivity) of the Ti-39Nb-7Zr alloy after RF are considered and sufficient thermal stability of the alloy up to 450 °C is demonstrated.","PeriodicalId":510812,"journal":{"name":"Metals","volume":"15 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140661622","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}
Timothée Cullaz, L. Saint-Sulpice, Mohammad Elahinia, S. Arbab Chirani
Rapid methods for assessing the fatigue properties of materials have been developed, among which the self-heating method stands out as particularly promising. This approach analyzes the thermal signal of the specimen when subjected to cyclic loading. In this research, the self-heating method was utilized for the first time with laser powder bed fusion (LPBF) of NiTi alloys, examining two specific loading conditions: loading ratios of 0.1 and 10. A thorough examination of the material self-heating behavior was conducted. For comparative purposes, conventional fatigue tests were also conducted, alongside interrupted fatigue tests designed to highlight the underlying mechanisms involved in high cycle fatigue and potentially self-heating behavior. The investigation revealed several key mechanisms at play, including intra-grain misorientation, the emergence and growth of persistent slip bands, and the formation of stress-induced martensite. These findings not only deepen our understanding of the fatigue behavior of LPBF NiTi alloys but also highlight the self-heating method potential as a tool for studying material fatigue.
目前已开发出评估材料疲劳特性的快速方法，其中尤以自加热法最有前途。这种方法分析的是试样在承受循环载荷时的热信号。在这项研究中，首次在镍钛合金的激光粉末床熔融（LPBF）中使用了自加热方法，研究了两种特定的加载条件：0.1 和 10 的加载比。对材料的自加热行为进行了全面检查。为了进行比较，还进行了传统的疲劳试验以及间断疲劳试验，目的是突出高循环疲劳和潜在自热行为所涉及的基本机制。调查揭示了几种关键的作用机制，包括晶粒内错位、持续滑移带的出现和增长以及应力诱导马氏体的形成。这些发现不仅加深了我们对 LPBF NiTi 合金疲劳行为的理解，而且凸显了自加热方法作为材料疲劳研究工具的潜力。
{"title":"Self-Heating and Fatigue Assessment of Laser Powder Bed Fusion NiTi Alloy with High Cycle Fatigue Mechanisms Identification","authors":"Timothée Cullaz, L. Saint-Sulpice, Mohammad Elahinia, S. Arbab Chirani","doi":"10.3390/met14050496","DOIUrl":"https://doi.org/10.3390/met14050496","url":null,"abstract":"Rapid methods for assessing the fatigue properties of materials have been developed, among which the self-heating method stands out as particularly promising. This approach analyzes the thermal signal of the specimen when subjected to cyclic loading. In this research, the self-heating method was utilized for the first time with laser powder bed fusion (LPBF) of NiTi alloys, examining two specific loading conditions: loading ratios of 0.1 and 10. A thorough examination of the material self-heating behavior was conducted. For comparative purposes, conventional fatigue tests were also conducted, alongside interrupted fatigue tests designed to highlight the underlying mechanisms involved in high cycle fatigue and potentially self-heating behavior. The investigation revealed several key mechanisms at play, including intra-grain misorientation, the emergence and growth of persistent slip bands, and the formation of stress-induced martensite. These findings not only deepen our understanding of the fatigue behavior of LPBF NiTi alloys but also highlight the self-heating method potential as a tool for studying material fatigue.","PeriodicalId":510812,"journal":{"name":"Metals","volume":"24 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140661730","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}
Deep cryogenic aging (DCA) is a newly developed heat treatment technique for additive-manufactured metallic materials to reduce residual stress and improve their mechanical properties. In this study, AlSi10Mg alloy samples fabricated by selective laser melting were deep-cryogenic-treated at −160 °C and subsequently aged at 160 °C. Phase and microstructural analyses were conducted using X-ray diffraction, optical microscopy, scanning electron microscopy, and transmission electron microscopy, while the mechanical properties were evaluated through microhardness and tensile testing at room temperature. The results indicated that the DCA treatment did not have an effect on the morphology of the melt pools. However, it facilitated the formation of atomic clusters and nanoscale Si and β′ phases, as well as accelerating the coarsening of grains and the ripening of the eutectic Si phase. After DCA treatment, the mass fraction of the Si phase experienced an increase from 4.4% to 7.2%. Concurrently, the volume fraction of the precipitated secondary phases elevated to 5.1%. The microhardness was enhanced to 147 HV, and the ultimate tensile strength and yield strength achieved 495 MPa and 345 MPa, respectively, with an elongation of 7.5%. In comparison to the as-built specimen, the microhardness, ultimate tensile strength, and yield strength increased by 11.4%, 3.1%, and 19.0%, respectively. The improvement in mechanical properties is primarily attributed to the Orowan strengthening mechanism induced by the secondary phases.
深低温老化（DCA）是一种新开发的热处理技术，适用于添加剂制造的金属材料，以减少残余应力并改善其机械性能。在这项研究中，通过选择性激光熔化技术制造的 AlSi10Mg 合金样品在 -160 °C 下进行了深冷处理，随后在 160 °C 下进行了老化。使用 X 射线衍射、光学显微镜、扫描电子显微镜和透射电子显微镜进行了相位和微观结构分析，并通过室温下的显微硬度和拉伸测试评估了力学性能。结果表明，DCA 处理对熔池的形态没有影响。但是，它促进了原子团簇和纳米级 Si 与 β′ 相的形成，并加速了晶粒的粗化和共晶 Si 相的成熟。经 DCA 处理后，硅相的质量分数从 4.4% 增加到 7.2%。同时，析出的次生相的体积分数上升到 5.1%。显微硬度提高到 147 HV，极限抗拉强度和屈服强度分别达到 495 兆帕和 345 兆帕，伸长率为 7.5%。与原试样相比，显微硬度、极限抗拉强度和屈服强度分别提高了 11.4%、3.1% 和 19.0%。机械性能的改善主要归功于次生相诱导的奥罗旺强化机制。
{"title":"Effect of Deep Cryogenic Aging Treatment on Microstructure and Mechanical Properties of Selective Laser-Melted AlSi10Mg Alloy","authors":"Pengjun Tang, Taiqi Yan, Yu Wu, Haibo Tang","doi":"10.3390/met14050493","DOIUrl":"https://doi.org/10.3390/met14050493","url":null,"abstract":"Deep cryogenic aging (DCA) is a newly developed heat treatment technique for additive-manufactured metallic materials to reduce residual stress and improve their mechanical properties. In this study, AlSi10Mg alloy samples fabricated by selective laser melting were deep-cryogenic-treated at −160 °C and subsequently aged at 160 °C. Phase and microstructural analyses were conducted using X-ray diffraction, optical microscopy, scanning electron microscopy, and transmission electron microscopy, while the mechanical properties were evaluated through microhardness and tensile testing at room temperature. The results indicated that the DCA treatment did not have an effect on the morphology of the melt pools. However, it facilitated the formation of atomic clusters and nanoscale Si and β′ phases, as well as accelerating the coarsening of grains and the ripening of the eutectic Si phase. After DCA treatment, the mass fraction of the Si phase experienced an increase from 4.4% to 7.2%. Concurrently, the volume fraction of the precipitated secondary phases elevated to 5.1%. The microhardness was enhanced to 147 HV, and the ultimate tensile strength and yield strength achieved 495 MPa and 345 MPa, respectively, with an elongation of 7.5%. In comparison to the as-built specimen, the microhardness, ultimate tensile strength, and yield strength increased by 11.4%, 3.1%, and 19.0%, respectively. The improvement in mechanical properties is primarily attributed to the Orowan strengthening mechanism induced by the secondary phases.","PeriodicalId":510812,"journal":{"name":"Metals","volume":"24 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140663687","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}
The preparation method of integrated circuit lead frames has transitioned from stamping to etching, rendering them more sensitive to residual stress. Consequently, the dimensional deviations caused by residual stress become more pronounced, necessitating a thorough investigation into the copper strip processing process, particularly considering the high-precision requirements of the lead frame. A quasi in situ method was employed to monitor the deformation process, and quantitative analyses and graphical reconstructions of the residual stress were conducted. The results indicated that the orientation evolution did not exhibit a significant correlation with grain size or grain aspect ratio. However, the stored energy of the different grains was related to their orientations. Further analysis of slip traces revealed that single or multiple slipping may be activated in grain subdivisions, and the Schmid factor difference ratio (SFDR) value proved to be an effective tool for analyzing this deformation mode. An even more interesting finding was that the deformation mode directly affected the residual stress distribution in local regions. The relationship between residual stress, Schmid factor, and SFDR was further analyzed, and a clear correlation between SFDR and residual stress was found in this study.
{"title":"Quasi In Situ Study on the Slipping Behavior and Residual Stress of Copper Strip","authors":"Yahui Liu, Qianqian Zhu, Yanjun Zhou, Kexing Song, Xiaokang Yang, Jing Chen","doi":"10.3390/met14050491","DOIUrl":"https://doi.org/10.3390/met14050491","url":null,"abstract":"The preparation method of integrated circuit lead frames has transitioned from stamping to etching, rendering them more sensitive to residual stress. Consequently, the dimensional deviations caused by residual stress become more pronounced, necessitating a thorough investigation into the copper strip processing process, particularly considering the high-precision requirements of the lead frame. A quasi in situ method was employed to monitor the deformation process, and quantitative analyses and graphical reconstructions of the residual stress were conducted. The results indicated that the orientation evolution did not exhibit a significant correlation with grain size or grain aspect ratio. However, the stored energy of the different grains was related to their orientations. Further analysis of slip traces revealed that single or multiple slipping may be activated in grain subdivisions, and the Schmid factor difference ratio (SFDR) value proved to be an effective tool for analyzing this deformation mode. An even more interesting finding was that the deformation mode directly affected the residual stress distribution in local regions. The relationship between residual stress, Schmid factor, and SFDR was further analyzed, and a clear correlation between SFDR and residual stress was found in this study.","PeriodicalId":510812,"journal":{"name":"Metals","volume":"81 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140670417","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}
Zibin Zuo, Mengping Duan, Xinyang Liu, Xiumin Chen, Huan Luo, Tengteng Shi, Xianjun Lei, Yang Tian, Bin Yang, Baoqiang Xu
Thermodynamic theory was employed in this study to investigate the feasibility of separating antimony (Sb) from crude arsenic (As) using vacuum sublimation. Ab initio molecular dynamics simulations are used to calculate the structure, stability, and diffusion properties of AsmSbn (m + n ≤ 6) clusters. As4, As3Sb, As2Sb2, and AsSb3 are the possible clusters in this thermodynamic calculation, and the molecular dynamics results confirmed their structural stability and stabilization in the gas phase. As4 had the largest diffusion coefficients, which is the reason it separates from the Sb-containing clusters (As3Sb, As2Sb2, and AsSb3) during gas-phase diffusion and condensation processes. The experimental results show that As vapor was transformed from crystalline to amorphous with increasing subcooling, and the Sb-containing clusters that enter the gas phase were mainly condensed and deposited at the proximal end of the heating zone. Not considering the volatilization rate, the removal rate of Sb in products can reach 99.35% by increasing the condensation disk and expanding the condensation zone; thus, experiments confirmed that industrial crude arsenic can realize deep Sb removal after vacuum sublimation.
本研究采用热力学理论研究了利用真空升华从粗砷（As）中分离锑（Sb）的可行性。Ab initio 分子动力学模拟用于计算 AsmSbn（m + n ≤ 6）团簇的结构、稳定性和扩散特性。As4、As3Sb、As2Sb2 和 AsSb3 是此次热力学计算中可能存在的团簇，分子动力学结果证实了它们在气相中的结构稳定性和稳定性。As4 的扩散系数最大，这也是它在气相扩散和凝结过程中与含锑团簇（As3Sb、As2Sb2 和 AsSb3）分离的原因。实验结果表明，随着过冷度的增加，As 蒸汽从晶体转变为无定形，进入气相的含锑簇主要在加热区的近端凝结沉积。在不考虑挥发率的情况下，通过增加冷凝盘和扩大冷凝区，产品中锑的去除率可达 99.35%；因此，实验证实了工业粗砷在真空升华后可实现深度除锑。
{"title":"Removal of Antimony from Industrial Crude Arsenic by Vacuum Sublimation: Combination of Thermodynamics and Ab Initio Molecular Dynamics","authors":"Zibin Zuo, Mengping Duan, Xinyang Liu, Xiumin Chen, Huan Luo, Tengteng Shi, Xianjun Lei, Yang Tian, Bin Yang, Baoqiang Xu","doi":"10.3390/met14050490","DOIUrl":"https://doi.org/10.3390/met14050490","url":null,"abstract":"Thermodynamic theory was employed in this study to investigate the feasibility of separating antimony (Sb) from crude arsenic (As) using vacuum sublimation. Ab initio molecular dynamics simulations are used to calculate the structure, stability, and diffusion properties of AsmSbn (m + n ≤ 6) clusters. As4, As3Sb, As2Sb2, and AsSb3 are the possible clusters in this thermodynamic calculation, and the molecular dynamics results confirmed their structural stability and stabilization in the gas phase. As4 had the largest diffusion coefficients, which is the reason it separates from the Sb-containing clusters (As3Sb, As2Sb2, and AsSb3) during gas-phase diffusion and condensation processes. The experimental results show that As vapor was transformed from crystalline to amorphous with increasing subcooling, and the Sb-containing clusters that enter the gas phase were mainly condensed and deposited at the proximal end of the heating zone. Not considering the volatilization rate, the removal rate of Sb in products can reach 99.35% by increasing the condensation disk and expanding the condensation zone; thus, experiments confirmed that industrial crude arsenic can realize deep Sb removal after vacuum sublimation.","PeriodicalId":510812,"journal":{"name":"Metals","volume":"102 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140670197","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}
Wenjie Zhang, Hongxi Liu, Zhiqiang Liu, Yuyao Liang, Yi Hao
Selective laser melting (SLM) technology used for the design and production of porous implants can successfully address the issues of stress shielding and aseptic loosening associated with the use of solid implants in the human body. In this paper, orthogonal experiments were used to optimize the process parameters for SLM molding of Ti-6Al-4V (TC4) material to investigate the effects of the process parameters on the densities, microscopic morphology, and roughness, and to determine the optimal process parameters using the roughness as a judging criterion. Based on the optimized process parameters, the mechanical properties of SLM-formed TC4 alloy specimens are investigated experimentally in this paper. The main conclusions are as follows: the optimal combination of roughness is obtained by polar analysis, the microhardness of SLM-molded TC4 alloy molded specimens is more uniform, the microhardness of specimens on the side and the front as well as the abrasion resistance is higher than that of casting specimens, the yield strength and tensile strength of specimens is higher than that of ASTM F136 standard and casting standard but the elongation is not as good as that of the standard, and the elasticity and compressive strength of porous specimens are higher than that of casting specimens at different volume fractions. The modulus of elasticity and compressive strength are within the range of human skeletal requirements. This work makes it possible to fabricate high-performance porous femoral joint implants from TC4 alloy SLM-molded materials.
{"title":"Experimental Study of Performance of Ti-6Al-4V Femoral Implants Using Selective Laser Melting (SLM) Methodology","authors":"Wenjie Zhang, Hongxi Liu, Zhiqiang Liu, Yuyao Liang, Yi Hao","doi":"10.3390/met14050492","DOIUrl":"https://doi.org/10.3390/met14050492","url":null,"abstract":"Selective laser melting (SLM) technology used for the design and production of porous implants can successfully address the issues of stress shielding and aseptic loosening associated with the use of solid implants in the human body. In this paper, orthogonal experiments were used to optimize the process parameters for SLM molding of Ti-6Al-4V (TC4) material to investigate the effects of the process parameters on the densities, microscopic morphology, and roughness, and to determine the optimal process parameters using the roughness as a judging criterion. Based on the optimized process parameters, the mechanical properties of SLM-formed TC4 alloy specimens are investigated experimentally in this paper. The main conclusions are as follows: the optimal combination of roughness is obtained by polar analysis, the microhardness of SLM-molded TC4 alloy molded specimens is more uniform, the microhardness of specimens on the side and the front as well as the abrasion resistance is higher than that of casting specimens, the yield strength and tensile strength of specimens is higher than that of ASTM F136 standard and casting standard but the elongation is not as good as that of the standard, and the elasticity and compressive strength of porous specimens are higher than that of casting specimens at different volume fractions. The modulus of elasticity and compressive strength are within the range of human skeletal requirements. This work makes it possible to fabricate high-performance porous femoral joint implants from TC4 alloy SLM-molded materials.","PeriodicalId":510812,"journal":{"name":"Metals","volume":"6 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140671793","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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