Pub Date : 2024-11-16DOI: 10.1016/j.intermet.2024.108560
Liming Fu , Zhian Song , Qigui Yang , Te Zhu , Rui Ma , Mingpan Wan , Peng Zhang , Runsheng Yu , Xingzhong Cao
Understanding the strengthening mechanism of high entropy alloys (HEA) is vital to improve their mechanical properties. In this study, we thoroughly investigated the strengthening effect of L12 nanoprecipitates on the mechanical properties of the face-centered cubic (FCC) CoCrFeNi HEA. The L12 nanoprecipitates were introduced by adding titanium (Ti), niobium (Nb), and aluminum (Al). Following a series of heat treatments (aged at 400 °C, 600 °C, and 800 °C for 4 h), the samples aged at 800 °C exhibited a noticeable improvement in tensile strength compared to the CoCrFeNi-based alloy, while maintaining excellent ductility (elongation greater than 29 %). This enhanced in performance is primarily attributed to the synergistic effects of multiple strengthening mechanisms, with precipitation strengthening playing a particularly prominent role (. Transmission electron microscopy (TEM) results revealed that the volume fraction of L12 precipitates reached 35 %, with sizes around 12 nm. This study provides valuable theoretical insights for optimizing the composition and processing strategies of high entropy alloys and lays a solid foundation for the development of high-performance alloys suited to complex engineering applications.
{"title":"Microstructure evolution and tensile properties behavior during aging temperature of CoCrFeNi-based high entropy alloys","authors":"Liming Fu , Zhian Song , Qigui Yang , Te Zhu , Rui Ma , Mingpan Wan , Peng Zhang , Runsheng Yu , Xingzhong Cao","doi":"10.1016/j.intermet.2024.108560","DOIUrl":"10.1016/j.intermet.2024.108560","url":null,"abstract":"<div><div>Understanding the strengthening mechanism of high entropy alloys (HEA) is vital to improve their mechanical properties. In this study, we thoroughly investigated the strengthening effect of L1<sub>2</sub> nanoprecipitates on the mechanical properties of the face-centered cubic (FCC) CoCrFeNi HEA. The L1<sub>2</sub> nanoprecipitates were introduced by adding titanium (Ti), niobium (Nb), and aluminum (Al). Following a series of heat treatments (aged at 400 °C, 600 °C, and 800 °C for 4 h), the samples aged at 800 °C exhibited a noticeable improvement in tensile strength compared to the CoCrFeNi-based alloy, while maintaining excellent ductility (elongation greater than 29 %). This enhanced in performance is primarily attributed to the synergistic effects of multiple strengthening mechanisms, with precipitation strengthening playing a particularly prominent role (<span><math><mrow><mrow><mo>Δ</mo><msub><mi>σ</mi><mi>P</mi></msub><mo>=</mo><mn>385.6</mn><mi>M</mi><mi>P</mi><mi>a</mi></mrow><mo>)</mo></mrow></math></span>. Transmission electron microscopy (TEM) results revealed that the volume fraction of L1<sub>2</sub> precipitates reached 35 %, with sizes around 12 nm. This study provides valuable theoretical insights for optimizing the composition and processing strategies of high entropy alloys and lays a solid foundation for the development of high-performance alloys suited to complex engineering applications.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"176 ","pages":"Article 108560"},"PeriodicalIF":4.3,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study explored the relationship between tribological performance and microstructural changes induced by heat treatment in a newly developed ZrNbTiVAl high-entropy alloy (HEA). The alloy was evaluated in its as-cast state and after heat treatments at 950 °C for 15, 20, and 25 h, with dry sliding experiments conducted against an alumina ball counterface. Advanced analytical techniques, including 3D optical profilometry, nanohardness testing, field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), and Micro-Raman spectroscopy, were employed for comprehensive surface analysis and to investigate oxide layer formation on the worn surfaces.
The study reveals a nuanced relationship between heat treatment duration, oxide layer formation, and frictional behavior in the ZrNbTiVAl high-entropy alloy (HEA). Increasing the heat treatment duration at 950 °C results in higher hardness (H) and a reduction in the modulus of elasticity (E) of the ZrNbTiVAl high-entropy alloy (HEA). Notably, wear rate and friction were lower in the as-cast and 15 h heat-treated conditions, despite their lower H/E and H³/E2 values compared to the 20 h and 25 h heat-treated states. Additionally, the wear mechanisms shift significantly, from mild adhesive/oxidative wear in the as-cast and 15 h conditions to severe adhesive/oxidative wear in the 20 h and 25 h conditions. This improved performance in the as-cast and 15 h conditions is attributed to the enrichment of Ti and V—elements recognized for their solid lubrication properties—and a reduced presence of Al-Zr intermetallics, which helps to minimize the formation of hard wear debris during dry sliding. These findings underscore the importance of optimizing heat treatment parameters to achieve superior tribological performance.
{"title":"Investigation of tribological properties of heat-treated ZrNbTiVAl high entropy alloy in dry sliding conditions","authors":"Neelima Khare , Poulami Chakraborty , Satish Chandra Mishra , Anurup Das , Praveen Kumar Limaye , Mahender Dev , Raghvendra Tewari","doi":"10.1016/j.intermet.2024.108573","DOIUrl":"10.1016/j.intermet.2024.108573","url":null,"abstract":"<div><div>This study explored the relationship between tribological performance and microstructural changes induced by heat treatment in a newly developed ZrNbTiVAl high-entropy alloy (HEA). The alloy was evaluated in its as-cast state and after heat treatments at 950 °C for 15, 20, and 25 h, with dry sliding experiments conducted against an alumina ball counterface. Advanced analytical techniques, including 3D optical profilometry, nanohardness testing, field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), and Micro-Raman spectroscopy, were employed for comprehensive surface analysis and to investigate oxide layer formation on the worn surfaces.</div><div>The study reveals a nuanced relationship between heat treatment duration, oxide layer formation, and frictional behavior in the ZrNbTiVAl high-entropy alloy (HEA). Increasing the heat treatment duration at 950 °C results in higher hardness (H) and a reduction in the modulus of elasticity (E) of the ZrNbTiVAl high-entropy alloy (HEA). Notably, wear rate and friction were lower in the as-cast and 15 h heat-treated conditions, despite their lower H/E and H³/E<sup>2</sup> values compared to the 20 h and 25 h heat-treated states. Additionally, the wear mechanisms shift significantly, from mild adhesive/oxidative wear in the as-cast and 15 h conditions to severe adhesive/oxidative wear in the 20 h and 25 h conditions. This improved performance in the as-cast and 15 h conditions is attributed to the enrichment of Ti and V—elements recognized for their solid lubrication properties—and a reduced presence of Al-Zr intermetallics, which helps to minimize the formation of hard wear debris during dry sliding. These findings underscore the importance of optimizing heat treatment parameters to achieve superior tribological performance.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"176 ","pages":"Article 108573"},"PeriodicalIF":4.3,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1016/j.intermet.2024.108574
Hongfu Su, Jingyi Hu, Mengyu Li, Jingbin Liu, Tong Gao, Xiangfa Liu
In this study, Al-5Ti, Al-18Si-5Ti, Al-12Si-2Sc and Al-12Si-1Sc-1Zr alloys, containing the Al3Ti, Ti7Al5Si12, AlSi2Sc2 and AlSi2(Sc, Zr)2 particles, respectively, were introduced into a Mg melt to understand the morphological and structural evolution behaviors of AlTM intermetallic compounds. Deposition layers at the bottom of the Mg melt were obtained due to the particle settlement. Scanning electron microscope and X-ray diffraction were employed to analyze the phase morphologies and structures of the AlTM intermetallic compounds in the deposition layers. A morphological transformation, characterized by the cracking of particles into fine clusters, was observed in all these AlTM intermetallic compounds, which is promoted by the inward diffusion of Mg atoms. The phase structures of the final particles remained Al3Ti and AlSi2Sc2 when Al-5Ti and Al-12Si-2Sc alloys were introduced into the Mg melt, indicating no structural evolution. However, structural evolutions were detected from Ti7Al5Si12 to Ti5Si4 and from AlSi2(Sc, Zr)2 to SiScZr when they were introduced in the Mg melt. It is hypothesized that the crystal structure, whether stoichiometric or non-stoichiometric, is closely related to the structural evolution behavior of AlTM intermetallic compounds. This work may provide new insights into phase control by introducing one type of metal matrix master alloy into another metal melt.
{"title":"The diversity of evolution behavior between stoichiometric and non-stoichiometric AlTM intermetallics in Mg melt","authors":"Hongfu Su, Jingyi Hu, Mengyu Li, Jingbin Liu, Tong Gao, Xiangfa Liu","doi":"10.1016/j.intermet.2024.108574","DOIUrl":"10.1016/j.intermet.2024.108574","url":null,"abstract":"<div><div>In this study, Al-5Ti, Al-18Si-5Ti, Al-12Si-2Sc and Al-12Si-1Sc-1Zr alloys, containing the Al<sub>3</sub>Ti, Ti<sub>7</sub>Al<sub>5</sub>Si<sub>12</sub>, AlSi<sub>2</sub>Sc<sub>2</sub> and AlSi<sub>2</sub>(Sc, Zr)<sub>2</sub> particles, respectively, were introduced into a Mg melt to understand the morphological and structural evolution behaviors of AlTM intermetallic compounds. Deposition layers at the bottom of the Mg melt were obtained due to the particle settlement. Scanning electron microscope and X-ray diffraction were employed to analyze the phase morphologies and structures of the AlTM intermetallic compounds in the deposition layers. A morphological transformation, characterized by the cracking of particles into fine clusters, was observed in all these AlTM intermetallic compounds, which is promoted by the inward diffusion of Mg atoms. The phase structures of the final particles remained Al<sub>3</sub>Ti and AlSi<sub>2</sub>Sc<sub>2</sub> when Al-5Ti and Al-12Si-2Sc alloys were introduced into the Mg melt, indicating no structural evolution. However, structural evolutions were detected from Ti<sub>7</sub>Al<sub>5</sub>Si<sub>12</sub> to Ti<sub>5</sub>Si<sub>4</sub> and from AlSi<sub>2</sub>(Sc, Zr)<sub>2</sub> to SiScZr when they were introduced in the Mg melt. It is hypothesized that the crystal structure, whether stoichiometric or non-stoichiometric, is closely related to the structural evolution behavior of AlTM intermetallic compounds. This work may provide new insights into phase control by introducing one type of metal matrix master alloy into another metal melt.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"176 ","pages":"Article 108574"},"PeriodicalIF":4.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1016/j.intermet.2024.108552
Guoqing Cao , Yanni Luo , Yu Fu, Qilin Wang, Huabei Peng, Yuhua Wen
Previous work has shown that the shape memory effect (SME) exhibited a strong negative dependence on the density of annealing twin boundaries (ATBs) in Fe-Mn-Si-based alloys. Reducing the density of ATBs has thus been an effective way to improve the SME of Fe-Mn-Si-based alloys. This study investigated the effects of trace B doping on the density of ATBs and the resultant SME in solution-treated Fe-Mn-Si-based alloys. Results indicated that doping 89 ppm B effectively reduced the density of ATBs in the solution-treated Fe-Mn-Si-based alloy. Consequently, its SME was remarkably improved. The maximum shape recovery strain reached 2.7 % in the B-doped alloy, 1.3 % higher than in the alloy without B doping. This work demonstrates a new avenue to improve the SME by doping trace B, which is of significance for the fabrication of Fe-Mn-Si-based shape memory alloys in a more cost-effective manner.
以往的研究表明，形状记忆效应（SME）与铁锰硅基合金中退火孪晶边界（ATB）的密度呈强烈的负相关。因此，降低 ATB 的密度是改善铁锰硅基合金 SME 的有效方法。本研究调查了溶液处理铁锰硅基合金中掺杂痕量硼对 ATB 密度和由此产生的 SME 的影响。结果表明，掺杂 89 ppm B 有效降低了溶液处理铁锰硅基合金中的 ATB 密度。因此，其 SME 显著提高。掺入硼的合金的最大形状恢复应变达到 2.7%，比未掺入硼的合金高出 1.3%。这项研究为通过掺杂痕量硼来改善 SME 提供了一条新途径，这对于以更具成本效益的方式制造铁锰硅形状记忆合金具有重要意义。
{"title":"Improving shape memory effect in Fe-Mn-Si-based alloys by reducing annealing twin boundaries through trace boron doping","authors":"Guoqing Cao , Yanni Luo , Yu Fu, Qilin Wang, Huabei Peng, Yuhua Wen","doi":"10.1016/j.intermet.2024.108552","DOIUrl":"10.1016/j.intermet.2024.108552","url":null,"abstract":"<div><div>Previous work has shown that the shape memory effect (SME) exhibited a strong negative dependence on the density of annealing twin boundaries (ATBs) in Fe-Mn-Si-based alloys. Reducing the density of ATBs has thus been an effective way to improve the SME of Fe-Mn-Si-based alloys. This study investigated the effects of trace B doping on the density of ATBs and the resultant SME in solution-treated Fe-Mn-Si-based alloys. Results indicated that doping 89 ppm B effectively reduced the density of ATBs in the solution-treated Fe-Mn-Si-based alloy. Consequently, its SME was remarkably improved. The maximum shape recovery strain reached 2.7 % in the B-doped alloy, 1.3 % higher than in the alloy without B doping. This work demonstrates a new avenue to improve the SME by doping trace B, which is of significance for the fabrication of Fe-Mn-Si-based shape memory alloys in a more cost-effective manner.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"176 ","pages":"Article 108552"},"PeriodicalIF":4.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1016/j.intermet.2024.108548
Vallapurapu Deva Praneeth , Manikandan R. , Pranav A.S. , Annamalai A. Raja , Muthuchamy A.
The present study examined the influence of ball milling on the evolution of microstructure, texture, and grain boundary distribution in hot press sintered cobalt-based alloy (60Co-15Al-15Ti-5Ta-5Nb). The key findings of this study reveal that the sample that underwent a 20-h ball milling followed by sintering has a high hardness of 1068 HV0.5, a relative sintered density of 85.65 %, and a high strength of 592 MPa. Additionally, it demonstrates that the use of ball milling for more than 20 h decreases the densification, thereby affected their mechanical properties.
{"title":"Influence of ball milling on the evolution of microstructure and microtexture in hot-press sintered cobalt alloy","authors":"Vallapurapu Deva Praneeth , Manikandan R. , Pranav A.S. , Annamalai A. Raja , Muthuchamy A.","doi":"10.1016/j.intermet.2024.108548","DOIUrl":"10.1016/j.intermet.2024.108548","url":null,"abstract":"<div><div>The present study examined the influence of ball milling on the evolution of microstructure, texture, and grain boundary distribution in hot press sintered cobalt-based alloy (60Co-15Al-15Ti-5Ta-5Nb). The key findings of this study reveal that the sample that underwent a 20-h ball milling followed by sintering has a high hardness of 1068 HV0.5, a relative sintered density of 85.65 %, and a high strength of 592 MPa. Additionally, it demonstrates that the use of ball milling for more than 20 h decreases the densification, thereby affected their mechanical properties.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"176 ","pages":"Article 108548"},"PeriodicalIF":4.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1016/j.intermet.2024.108554
Di Wang , Aidong Lan , Huijun Yang , Xi Jin , Junwei Qiao
The pitting and passivation film properties of Ce-modified Fe40Mn20Cr20Ni20 high-entropy alloys in artificial seawater were investigated. Corrosion morphology and kinetic potential polarization curves indicated that the doping of Ce changed the compositions of the alloy inclusions, increased the pitting potentials and reduced the alloy's sensitivity to pitting. The reduction of the defect density and the diffusion coefficient of pitting defects () within the passivate film proved the effectiveness of Ce in enhancing the protective property of the passivate film, with Ce-0.10 being the most prominent.
研究了人工海水中 Ce 改性 Fe40Mn20Cr20Ni20 高熵合金的点蚀和钝化膜性能。腐蚀形态和动力学电位极化曲线表明，掺入 Ce 改变了合金夹杂物的成分，提高了点蚀电位，降低了合金对点蚀的敏感性。钝化膜内缺陷密度和点蚀缺陷扩散系数（D0）的降低证明了 Ce 在增强钝化膜保护性能方面的有效性，其中以 Ce-0.10 的效果最为显著。
{"title":"Corrosion and passivation behavior of Fe40Mn20Cr20Ni20 high-entropy alloys in artificial seawater: Effect of rare earth Ce","authors":"Di Wang , Aidong Lan , Huijun Yang , Xi Jin , Junwei Qiao","doi":"10.1016/j.intermet.2024.108554","DOIUrl":"10.1016/j.intermet.2024.108554","url":null,"abstract":"<div><div>The pitting and passivation film properties of Ce-modified Fe<sub>40</sub>Mn<sub>20</sub>Cr<sub>20</sub>Ni<sub>20</sub> high-entropy alloys in artificial seawater were investigated. Corrosion morphology and kinetic potential polarization curves indicated that the doping of Ce changed the compositions of the alloy inclusions, increased the pitting potentials and reduced the alloy's sensitivity to pitting. The reduction of the defect density and the diffusion coefficient of pitting defects (<span><math><mrow><msub><mi>D</mi><mn>0</mn></msub></mrow></math></span>) within the passivate film proved the effectiveness of Ce in enhancing the protective property of the passivate film, with Ce-0.10 being the most prominent.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"176 ","pages":"Article 108554"},"PeriodicalIF":4.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1016/j.intermet.2024.108556
V.M. Imayev, D.M. Trofimov, R.M. Imayev
In the present work, two β-solidifying γ-TiAl based intermetallic alloys, Ti-43.5Al-4Nb-1Mo-0.1B (TNM) and Ti-43.5Al-6(Nb,Zr,Hf)-0.1B (TNZ) (at.%), have been comparatively studied. Two microstructural conditions per alloy, near duplex and near lamellar, were obtained in the alloys by isothermal upset forging and two-stage heat treatments. Microstructure examination revealed three phases (γ, α2 and β(βo)) in both alloys but in the TNZ alloy the β(βo) phase content was less than 1 vol% in contrast to the TNM alloy, in which the β(βo) phase content was varied within 4–8 vol%. The near duplex conditions of the alloys were similar, whereas a coarser microstructure was obtained in the TNZ alloy with near lamellar structure. The tensile and creep tests revealed that the brittle-ductile transition in the TNZ alloy occurred at higher temperatures that correlated with an appreciably higher creep resistance of the TNZ alloy as compared to the TNM alloy. In the near lamellar condition, the TNZ alloy showed superior strength at 900–1000 °C as compared to known γ-TiAl alloys (e.g. UTS = 554 MPa at 950 °C). The oxidation resistance of the alloys in the near lamellar conditions was evaluated during exposure at 800 °C for 1000 h. The TNZ alloy showed higher oxidation resistance and thus generally appreciably higher high-temperature capability than the TNM alloy. It has been shown that the fundamental reason for different temperatures of the brittle-ductile transition and different creep and oxidation resistance of the alloys is the enhanced thermal stability of the microstructure of the TNZ alloy compared to the TNM alloy.
{"title":"Microstructure, mechanical properties and oxidation resistance of β-solidifying γ-TiAl based alloys","authors":"V.M. Imayev, D.M. Trofimov, R.M. Imayev","doi":"10.1016/j.intermet.2024.108556","DOIUrl":"10.1016/j.intermet.2024.108556","url":null,"abstract":"<div><div>In the present work, two β-solidifying γ-TiAl based intermetallic alloys, Ti-43.5Al-4Nb-1Mo-0.1B (TNM) and Ti-43.5Al-6(Nb,Zr,Hf)-0.1B (TNZ) (at.%), have been comparatively studied. Two microstructural conditions per alloy, near duplex and near lamellar, were obtained in the alloys by isothermal upset forging and two-stage heat treatments. Microstructure examination revealed three phases (γ, α<sub>2</sub> and β(β<sub>o</sub>)) in both alloys but in the TNZ alloy the β(β<sub>o</sub>) phase content was less than 1 vol% in contrast to the TNM alloy, in which the β(β<sub>o</sub>) phase content was varied within 4–8 vol%. The near duplex conditions of the alloys were similar, whereas a coarser microstructure was obtained in the TNZ alloy with near lamellar structure. The tensile and creep tests revealed that the brittle-ductile transition in the TNZ alloy occurred at higher temperatures that correlated with an appreciably higher creep resistance of the TNZ alloy as compared to the TNM alloy. In the near lamellar condition, the TNZ alloy showed superior strength at 900–1000 °C as compared to known γ-TiAl alloys (e.g. UTS = 554 MPa at 950 °C). The oxidation resistance of the alloys in the near lamellar conditions was evaluated during exposure at 800 °C for 1000 h. The TNZ alloy showed higher oxidation resistance and thus generally appreciably higher high-temperature capability than the TNM alloy. It has been shown that the fundamental reason for different temperatures of the brittle-ductile transition and different creep and oxidation resistance of the alloys is the enhanced thermal stability of the microstructure of the TNZ alloy compared to the TNM alloy.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"176 ","pages":"Article 108556"},"PeriodicalIF":4.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.intermet.2024.108555
Xutao Wang , Benpeng Wang , Xudong Liu , Tianxiang Li , Hanlin Zeng , Liang Wang , Ke Jin , Yunfei Xue
Precipitation-hardened high entropy alloys (PHEAs) are promising candidates for shaped charge liners (SCLs) due to their potential in obtaining good penetration depth and diameter. Deformation mechanism under explosive is the key to guiding the alloys microstructure, property optimization and shaped charge designing. In this study, the microstructural evolution and deformation mechanism of PHEA SCLs under explosive loading were systematically investigated. Under explosive loading, both the α2 and BCC matrix phases underwent dynamic recrystallization, transforming into fine equiaxed grains (∼10 μm). The BCC phase deformed earlier than the α2 phase, exhibiting a clearly asynchronous deformation behavior. This demonstrates that the α2 phase can effectively improve the deformation resistance upon detonation and further increase jet diameter. Moreover, the α2 can be retained under explosive conditions, which enables delaying the expansion of the adiabatic shear bands and further improving the jet continuity. Our results shed lights on developing new high-performance alloys and the related microstructure optimization for engineering applications in SCLs.
{"title":"Asynchronous deformation behavior of precipitation-hardened high-entropy alloys shaped charge liner under explosive loading","authors":"Xutao Wang , Benpeng Wang , Xudong Liu , Tianxiang Li , Hanlin Zeng , Liang Wang , Ke Jin , Yunfei Xue","doi":"10.1016/j.intermet.2024.108555","DOIUrl":"10.1016/j.intermet.2024.108555","url":null,"abstract":"<div><div>Precipitation-hardened high entropy alloys (PHEAs) are promising candidates for shaped charge liners (SCLs) due to their potential in obtaining good penetration depth and diameter. Deformation mechanism under explosive is the key to guiding the alloys microstructure, property optimization and shaped charge designing. In this study, the microstructural evolution and deformation mechanism of PHEA SCLs under explosive loading were systematically investigated. Under explosive loading, both the α<sub>2</sub> and BCC matrix phases underwent dynamic recrystallization, transforming into fine equiaxed grains (∼10 μm). The BCC phase deformed earlier than the α<sub>2</sub> phase, exhibiting a clearly asynchronous deformation behavior. This demonstrates that the α<sub>2</sub> phase can effectively improve the deformation resistance upon detonation and further increase jet diameter. Moreover, the α<sub>2</sub> can be retained under explosive conditions, which enables delaying the expansion of the adiabatic shear bands and further improving the jet continuity. Our results shed lights on developing new high-performance alloys and the related microstructure optimization for engineering applications in SCLs.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"176 ","pages":"Article 108555"},"PeriodicalIF":4.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.intermet.2024.108571
Yongqiang Deng , Sajjad Ur Rehman , Zhihao Liu , Haihua Liu , Shuwei Zhong , Xiaoqiang Yu , Jiajie Li , Munan Yang
The CeFe2 paramagnetic phase consumes a large amount of Ce in the Ce-Fe-B, deteriorating the magnetic properties of the alloys. Due to the significant consumption of Ce element in the CeFe2 phase, the content of Ce is maintained at a high level, i.e., up to 35–37 wt% in the Ce-Fe-B alloys. In this paper, we report the magnetic properties of Ce-Fe-B alloys by adding Ge, which suppresses the formation of the CeFe2 phase. The content of Ce is reduced from 35 to 28.5 wt%, resulting in a significant reduction in the volume fraction of the CeFe2 from 10.3 wt% in the Ce35Fe63.5Ge0.5B alloy to 1.6 wt% in the Ce31.1Fe67.4Ge0.5B alloy. The soft magnetic α-Fe phase is formed when the content of Ce is reduced to 29.8 and 28.5 wt%. The intrinsic coercivity of the alloys decreased from 490 kA/m in the pristine alloy to 410 kA/m in the Ce29.8Fe68.7Ge0.5B alloy. The remanence of the alloys increased from 0.46 T in the pristine alloy to 0.59 T in the Ce29.8Fe68.7Ge0.5B alloy. More strikingly, the maximum energy density, which is the figure of merit for permanent magnets, increased from 33.8 kJ/m3 to 52.3 kJ/m3, showing an increment of ∼55 %. The phase constituents, microstructure, phase transition temperatures, magnetic interactions, and applicability of the alloys have been investigated in detail using XRD Rietveld refinement, transmission electron microscopy and various magnetic property measurements.
{"title":"Tailoring the magnetic properties of Ce-Fe-B alloys by controlling the CeFe2 paramagnetic phase","authors":"Yongqiang Deng , Sajjad Ur Rehman , Zhihao Liu , Haihua Liu , Shuwei Zhong , Xiaoqiang Yu , Jiajie Li , Munan Yang","doi":"10.1016/j.intermet.2024.108571","DOIUrl":"10.1016/j.intermet.2024.108571","url":null,"abstract":"<div><div>The CeFe<sub>2</sub> paramagnetic phase consumes a large amount of Ce in the Ce-Fe-B, deteriorating the magnetic properties of the alloys. Due to the significant consumption of Ce element in the CeFe<sub>2</sub> phase, the content of Ce is maintained at a high level, i.e., up to 35–37 wt% in the Ce-Fe-B alloys. In this paper, we report the magnetic properties of Ce-Fe-B alloys by adding Ge, which suppresses the formation of the CeFe<sub>2</sub> phase. The content of Ce is reduced from 35 to 28.5 wt%, resulting in a significant reduction in the volume fraction of the CeFe<sub>2</sub> from 10.3 wt% in the Ce<sub>35</sub>Fe<sub>63.5</sub>Ge<sub>0.5</sub>B alloy to 1.6 wt% in the Ce<sub>31.1</sub>Fe<sub>67.4</sub>Ge<sub>0.5</sub>B alloy. The soft magnetic α-Fe phase is formed when the content of Ce is reduced to 29.8 and 28.5 wt%. The intrinsic coercivity of the alloys decreased from 490 kA/m in the pristine alloy to 410 kA/m in the Ce<sub>29.8</sub>Fe<sub>68.7</sub>Ge<sub>0.5</sub>B alloy. The remanence of the alloys increased from 0.46 T in the pristine alloy to 0.59 T in the Ce<sub>29.8</sub>Fe<sub>68.7</sub>Ge<sub>0.5</sub>B alloy. More strikingly, the maximum energy density, which is the figure of merit for permanent magnets, increased from 33.8 kJ/m<sup>3</sup> to 52.3 kJ/m<sup>3</sup>, showing an increment of ∼55 %. The phase constituents, microstructure, phase transition temperatures, magnetic interactions, and applicability of the alloys have been investigated in detail using XRD Rietveld refinement, transmission electron microscopy and various magnetic property measurements.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"176 ","pages":"Article 108571"},"PeriodicalIF":4.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-11DOI: 10.1016/j.intermet.2024.108572
Guofu Lian , Jiangbin Chen , Jianghuai Yang , Meiyan Feng , Song Lan
Excellent alloys were prepared to explore the effects of different additions of element M on CoCrFeNiTi-based high entropy alloys by laser cladding under different process parameters. The preset-powder method was used to prepare CoCrFeNiTi_0.5M_0.5 (M = Mo, Cu, and Al) coating in the work. The material properties of high entropy alloys were calculated based on the first principle. After that, the influence mechanism of the addition of M on the CoCrFeNiTi-based high entropy alloy was explored by experiments. The phasing standards of coatings added with M were calculated according to the first principle. It was predicted that CoCrFeNiTi_0.5Mo_0.5 coating and CoCrFeNiTi_0.5Cu_0.5 coating had high hardness and toughness, respectively. All six high-entropy alloys were stable in mechanics. The optimal process parameter coating was selected by the all-factor test based on excellent hardness and shaping quality. The results were consistent with those by theoretical calculations. The cocktail effect of high-entropy alloys was explored by analyzing the effect of different elemental additions on the overall performance of coatings. Results showed that the CoCrFeNiTi_0.5Mo_0.5 coating had high wear resistance and local elastic modulus. The friction mass loss and local elastic modulus were 0.0410 mm3 and 279.0444 GPa, respectively. The CoCrFeNiTi_0.5Cu_0.5 coating had high toughness and corrosion resistance. The resilience and free corrosion potential were 81.6473 nm and −0.730 V, respectively. The CoCrFeNiTi_0.5Al_0.5 coating had good crack resistance. Plastic storage energy was 30071.5097 × 10−15 J. Research results provided a theoretical basis for preparing high entropy alloy reinforced coatings by laser cladding.
{"title":"Influences of element M (M=Mo, Cu, and Al) on CoCrFeNiTi-based high entropy alloys by laser cladding under different process parameters","authors":"Guofu Lian , Jiangbin Chen , Jianghuai Yang , Meiyan Feng , Song Lan","doi":"10.1016/j.intermet.2024.108572","DOIUrl":"10.1016/j.intermet.2024.108572","url":null,"abstract":"<div><div>Excellent alloys were prepared to explore the effects of different additions of element M on CoCrFeNiTi-based high entropy alloys by laser cladding under different process parameters. The preset-powder method was used to prepare CoCrFeNiTi_0.5M_0.5 (M = Mo, Cu, and Al) coating in the work. The material properties of high entropy alloys were calculated based on the first principle. After that, the influence mechanism of the addition of M on the CoCrFeNiTi-based high entropy alloy was explored by experiments. The phasing standards of coatings added with M were calculated according to the first principle. It was predicted that CoCrFeNiTi_0.5Mo_0.5 coating and CoCrFeNiTi_0.5Cu_0.5 coating had high hardness and toughness, respectively. All six high-entropy alloys were stable in mechanics. The optimal process parameter coating was selected by the all-factor test based on excellent hardness and shaping quality. The results were consistent with those by theoretical calculations. The cocktail effect of high-entropy alloys was explored by analyzing the effect of different elemental additions on the overall performance of coatings. Results showed that the CoCrFeNiTi_0.5Mo_0.5 coating had high wear resistance and local elastic modulus. The friction mass loss and local elastic modulus were 0.0410 mm<sup>3</sup> and 279.0444 GPa, respectively. The CoCrFeNiTi_0.5Cu_0.5 coating had high toughness and corrosion resistance. The resilience and free corrosion potential were 81.6473 nm and −0.730 V, respectively. The CoCrFeNiTi_0.5Al_0.5 coating had good crack resistance. Plastic storage energy was 30071.5097 × 10<sup>−15</sup> J. Research results provided a theoretical basis for preparing high entropy alloy reinforced coatings by laser cladding.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"176 ","pages":"Article 108572"},"PeriodicalIF":4.3,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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