Pub Date : 2026-01-19DOI: 10.1016/j.ijrmhm.2026.107684
Jiahao Huang , Huanan Wei , Tie Han , Zhikai Zhang , Zhenhua Yu , Mingbo Zhang , Chun Cheng , Xu Wang , Yuxuan Zheng
This study systematically investigates the effects of W and V additions on the phase composition, microstructure, mechanical properties, and fracture-induced ignition behavior of TiZrNb-based high-entropy alloys under quasi-static and dynamic loading. Under dynamic loading (∼3000 s−1), the TiZrNbW alloy exhibits the highest yield strength (2298 MPa) but limited fracture strain (∼11%). In contrast, the TiZrNbV alloy shows superior ductility (fracture strain ∼26%) with a yield strength of 1551 MPa. The co-addition of W and V achieves a balanced strength–toughness profile under high strain-rate conditions, as demonstrated by the TiZrNbWV alloy with a yield strength of 1911 MPa and fracture strain of 12.9–16.7%. Energy-release intensity correlates directly with fragmentation degree: the more brittle TiZrNbW undergoes severe fragmentation and releases the most intense energy. XPS and EDS analyses confirm that oxidation reactions (forming TiO2, ZrO2, Nb2O5, V2O5, WO2, and WO3) constitute the core ignition mechanism. Quantitative XPS analysis reveals that the TiZrNbW alloy undergoes a more extensive oxidation process, with the sum of oxidation proportions for its constituent elements reaching 249%, compared to 223% for the TiZrNbV alloy. This higher overall oxidation degree correlates directly with its more intense energy release. No ignition occurs in oxygen-free environments, underscoring the essential role of oxidation in fracture-induced energy release.
{"title":"The influence of W and V elements on the mechanical properties and fracture ignition behavior of TiZrNb-based high-entropy alloys","authors":"Jiahao Huang , Huanan Wei , Tie Han , Zhikai Zhang , Zhenhua Yu , Mingbo Zhang , Chun Cheng , Xu Wang , Yuxuan Zheng","doi":"10.1016/j.ijrmhm.2026.107684","DOIUrl":"10.1016/j.ijrmhm.2026.107684","url":null,"abstract":"<div><div>This study systematically investigates the effects of W and V additions on the phase composition, microstructure, mechanical properties, and fracture-induced ignition behavior of TiZrNb-based high-entropy alloys under quasi-static and dynamic loading. Under dynamic loading (∼3000 s<sup>−1</sup>), the TiZrNbW alloy exhibits the highest yield strength (2298 MPa) but limited fracture strain (∼11%). In contrast, the TiZrNbV alloy shows superior ductility (fracture strain ∼26%) with a yield strength of 1551 MPa. The co-addition of W and V achieves a balanced strength–toughness profile under high strain-rate conditions, as demonstrated by the TiZrNbWV alloy with a yield strength of 1911 MPa and fracture strain of 12.9–16.7%. Energy-release intensity correlates directly with fragmentation degree: the more brittle TiZrNbW undergoes severe fragmentation and releases the most intense energy. XPS and EDS analyses confirm that oxidation reactions (forming TiO<sub>2</sub>, ZrO<sub>2</sub>, Nb<sub>2</sub>O<sub>5</sub>, V<sub>2</sub>O<sub>5</sub>, WO<sub>2</sub>, and WO<sub>3</sub>) constitute the core ignition mechanism. Quantitative XPS analysis reveals that the TiZrNbW alloy undergoes a more extensive oxidation process, with the sum of oxidation proportions for its constituent elements reaching 249%, compared to 223% for the TiZrNbV alloy. This higher overall oxidation degree correlates directly with its more intense energy release. No ignition occurs in oxygen-free environments, underscoring the essential role of oxidation in fracture-induced energy release.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107684"},"PeriodicalIF":4.6,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000676","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 : 2026-01-19DOI: 10.1016/j.ijrmhm.2026.107678
Jianning Gan , Yunfeng Feng , Rongpei Wang , Keyang Li , Zhiqing Xu , Mengda Hou , Ruoyu Qi , Ming Zhao , Xiaobo Han , Jingyuan Zhang , Yuehuan Li , Baorui Du , Feng Lin , Daming Zhuang , Hao Chen , Qianming Gong
Strong textures are always the inevitable hurdles in achieving isotropic performance for pure tungsten (W) manufactured by laser powder bed fusion (LPBF) or electron beam powder bed fusion (EB-PBF). Intrinsically, the ultimate texture is determined by the characters of original molten pool and so in this work, the correlation between the molten pool morphology of pure tungsten during LPBF and EB-PBF process and the ultimate solidification microstructure was explored by experiments and finite element analyses (FEAs). The molten pool morphology of LPBF W was deep and narrow, being called the keyhole mode, and in contrast, the molten pool morphology of EB-PBF W was shallow and wide, being called the conduction mode. According to FEAs, we found that the direction of temperature gradient was generally vertical to the contour line of molten pool bottom towards the center of the molten pool surface. In the keyhole mode molten pool during LPBF process, due to the large depth-to-width ratio, the direction of temperature gradient, pointing centripetally from the bottom contour line to the upper center of the molten pool, changed sharply with the shrinking of molten pool during solidification process, consequently, the primary dendrites, initially vertical to the contour line of molten pool bottom, would collide with each other during their growing along the rapidly varying direction of the temperature gradient, and thus the unidirectional epitaxial growth of primary dendrites would be interrupted, which resulted in bowl-shaped grains and 〈111〉 textures. Differently, the direction of temperature gradient would change more slowly along the shrinking of molten pool during the solidification process of EB-PBF process for the depth-to-width ratio was much smaller in the conduction mode than that in the keyhole mode, so the unidirectional epitaxial growth of the primary dendrites could continue without frequent interruption, and thus typical columnar grains and <111>, 〈001〉 binary textures were formed in EB-PBF W. The results about the correlation of the molten pool morphology and the ultimate microstructure might conduce to find novel approaches for tailoring the textures of tungsten prepared by additive manufacturing.
{"title":"Correlation analyses of molten pool morphology and microstructure of tungsten prepared via powder bed fusion additive manufacturing","authors":"Jianning Gan , Yunfeng Feng , Rongpei Wang , Keyang Li , Zhiqing Xu , Mengda Hou , Ruoyu Qi , Ming Zhao , Xiaobo Han , Jingyuan Zhang , Yuehuan Li , Baorui Du , Feng Lin , Daming Zhuang , Hao Chen , Qianming Gong","doi":"10.1016/j.ijrmhm.2026.107678","DOIUrl":"10.1016/j.ijrmhm.2026.107678","url":null,"abstract":"<div><div>Strong textures are always the inevitable hurdles in achieving isotropic performance for pure tungsten (W) manufactured by laser powder bed fusion (LPBF) or electron beam powder bed fusion (EB-PBF). Intrinsically, the ultimate texture is determined by the characters of original molten pool and so in this work, the correlation between the molten pool morphology of pure tungsten during LPBF and EB-PBF process and the ultimate solidification microstructure was explored by experiments and finite element analyses (FEAs). The molten pool morphology of LPBF W was deep and narrow, being called the keyhole mode, and in contrast, the molten pool morphology of EB-PBF W was shallow and wide, being called the conduction mode. According to FEAs, we found that the direction of temperature gradient was generally vertical to the contour line of molten pool bottom towards the center of the molten pool surface. In the keyhole mode molten pool during LPBF process, due to the large depth-to-width ratio, the direction of temperature gradient, pointing centripetally from the bottom contour line to the upper center of the molten pool, changed sharply with the shrinking of molten pool during solidification process, consequently, the primary dendrites, initially vertical to the contour line of molten pool bottom, would collide with each other during their growing along the rapidly varying direction of the temperature gradient, and thus the unidirectional epitaxial growth of primary dendrites would be interrupted, which resulted in bowl-shaped grains and 〈111〉 textures. Differently, the direction of temperature gradient would change more slowly along the shrinking of molten pool during the solidification process of EB-PBF process for the depth-to-width ratio was much smaller in the conduction mode than that in the keyhole mode, so the unidirectional epitaxial growth of the primary dendrites could continue without frequent interruption, and thus typical columnar grains and <111>, 〈001〉 binary textures were formed in EB-PBF W. The results about the correlation of the molten pool morphology and the ultimate microstructure might conduce to find novel approaches for tailoring the textures of tungsten prepared by additive manufacturing.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107678"},"PeriodicalIF":4.6,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000675","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 : 2026-01-17DOI: 10.1016/j.ijrmhm.2026.107682
S. Fooladi Mahani , C. Liu , J. Dong , X. Wen , G. Ramírez , B.L. Liu , L. Llanes
Cemented carbides are widely used in structural and tooling applications where high mechanical reliability is essential. Owing to their inherently brittle nature, fracture in these materials is typically governed by the propagation of microstructural or processing-induced flaws. Developing a robust and practical methodology for accurately determining their fracture toughness is therefore critical to ensure safe, reliable, and efficient performance in demanding service conditions. This study proposes to assess fracture toughness by means of a strategy that couples controlled introduction of artificial flaws via nanosecond-pulsed laser ablation with post-mortem analysis of broken surfaces through quantitative fractography. Two fine-grained WC-Co cemented carbide grades, differing in binder content, were selected to examine the proposed approach. Artificial microdimples, designed to control failure initiation sites, were created under optimized laser conditions and subjected to monotonic and cyclic loading in four-point bending. Fractographic analysis provided key parameters, flaw size and mirror radius, for fracture toughness estimation based on mirror-mist-hackle geometry. To validate the approach, additional measurements were carried out using two other methods: indentation fracture toughness and flexural testing of single-edge notched and pre-cracked beams. Statistical analysis showed that the combined controlled defect-quantitative fractography method yields reliable fracture toughness values. They closely match the reference baseline values determined by using tests involving specimens with well-defined through-thickness sharp cracks, and confirm the toughness overestimation often observed in tougher grades when implementing the indentation method.
{"title":"Assessment of fracture toughness of cemented carbides by coupling introduction of artificial flaws via laser ablation with quantitative fractography","authors":"S. Fooladi Mahani , C. Liu , J. Dong , X. Wen , G. Ramírez , B.L. Liu , L. Llanes","doi":"10.1016/j.ijrmhm.2026.107682","DOIUrl":"10.1016/j.ijrmhm.2026.107682","url":null,"abstract":"<div><div>Cemented carbides are widely used in structural and tooling applications where high mechanical reliability is essential. Owing to their inherently brittle nature, fracture in these materials is typically governed by the propagation of microstructural or processing-induced flaws. Developing a robust and practical methodology for accurately determining their fracture toughness is therefore critical to ensure safe, reliable, and efficient performance in demanding service conditions. This study proposes to assess fracture toughness by means of a strategy that couples controlled introduction of artificial flaws via nanosecond-pulsed laser ablation with post-mortem analysis of broken surfaces through quantitative fractography. Two fine-grained WC-Co cemented carbide grades, differing in binder content, were selected to examine the proposed approach. Artificial microdimples, designed to control failure initiation sites, were created under optimized laser conditions and subjected to monotonic and cyclic loading in four-point bending. Fractographic analysis provided key parameters, flaw size and mirror radius, for fracture toughness estimation based on mirror-mist-hackle geometry. To validate the approach, additional measurements were carried out using two other methods: indentation fracture toughness and flexural testing of single-edge notched and pre-cracked beams. Statistical analysis showed that the combined controlled defect-quantitative fractography method yields reliable fracture toughness values. They closely match the reference baseline values determined by using tests involving specimens with well-defined through-thickness sharp cracks, and confirm the toughness overestimation often observed in tougher grades when implementing the indentation method.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"138 ","pages":"Article 107682"},"PeriodicalIF":4.6,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995330","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 : 2026-01-16DOI: 10.1016/j.ijrmhm.2026.107677
Feng Liu , Xiangyang Shen , Yue Zhang , Fuyu Dong , Binbin Wang , Yanqing Su
NbMoTaW refractory high-entropy alloys (RHEAs) exhibit excellent mechanical properties at high temperatures. However, they are not suited for many practical applications due to their limited room-temperature plasticity. A novel compositional optimization strategy based on partial substitution of W with Zr was implemented in this study. A series of NbMoTaZrx (x = 0, 0.2, 0.6, 1.0, 1.4) RHEAs were fabricated via vacuum arc melting, then their microstructures, phase compositions, and mechanical properties were systematically characterized. All exhibited a BCC1 phase enriched with Ta, Mo, and Nb, along with a Zr-dominated BCC2 phase of a typical dendritic structure. The compressive plasticity at room temperature significantly improved with increasing Zr content, while the compressive yield strength initially increased and then decreased. The samples' enhanced mechanical performance can be attributed to solid solution strengthening, an increased volume fraction of interdendritic regions, and grain refinement. The fracture mode was also found to transition from intergranular fracture in NbMoTa RHEAs to cleavage fracture in NbMoTaZr1.4 RHEAs.
{"title":"Improved compressive plasticity in refractory high-entropy alloys: Substituting W with Zr as a novel compositional optimization strategy","authors":"Feng Liu , Xiangyang Shen , Yue Zhang , Fuyu Dong , Binbin Wang , Yanqing Su","doi":"10.1016/j.ijrmhm.2026.107677","DOIUrl":"10.1016/j.ijrmhm.2026.107677","url":null,"abstract":"<div><div>NbMoTaW refractory high-entropy alloys (RHEAs) exhibit excellent mechanical properties at high temperatures. However, they are not suited for many practical applications due to their limited room-temperature plasticity. A novel compositional optimization strategy based on partial substitution of W with Zr was implemented in this study. A series of NbMoTaZr<sub>x</sub> (x = 0, 0.2, 0.6, 1.0, 1.4) RHEAs were fabricated via vacuum arc melting, then their microstructures, phase compositions, and mechanical properties were systematically characterized. All exhibited a BCC1 phase enriched with Ta, Mo, and Nb, along with a Zr-dominated BCC2 phase of a typical dendritic structure. The compressive plasticity at room temperature significantly improved with increasing Zr content, while the compressive yield strength initially increased and then decreased. The samples' enhanced mechanical performance can be attributed to solid solution strengthening, an increased volume fraction of interdendritic regions, and grain refinement. The fracture mode was also found to transition from intergranular fracture in NbMoTa RHEAs to cleavage fracture in NbMoTaZr<sub>1.4</sub> RHEAs.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107677"},"PeriodicalIF":4.6,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035242","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 : 2026-01-16DOI: 10.1016/j.ijrmhm.2026.107681
Peng-Cheng Cai , Kai-Fei Wang , Guo-Hua Zhang , Kuo-Chih Chou
WCu composites combine high strength, rigidity, and low thermal expansion coefficient of W with excellent electrical and thermal conductivity of Cu, endowing them with broad application prospects in a broad application. However, the intrinsic immiscibility between W and Cu leads weak interfacial bonding, posing a long-standing challenge to their high-performance applications. Although the introduction of a third component is widely recognized as an effective mean of improving interfacial compatibility, it is often achieved at the expense of electrical and thermal performance. In this study, fine-grained WCu composites were subjected to precisely tailored thermomechanical processing (rolling and annealing). On the one hand, the formation of heterointerface-induced stacking faults was promoted, and the substructures introduced by rolling enhanced the plastic deformability of the W particles. Through these coupled effects, load transfer and dislocation motion across the two phases were effectively regulated, leading to a pronounced improvement in overall mechanical performance. On the other hand, the continuity of the Cu phase was enhanced and charge transport pathways were optimized, thereby resulting in improvement of electrical conductivity. These findings provide new insights into the tuning of phase configurations in immiscible metal composites, offering a viable pathway for the synergistic optimization of multiple properties.
{"title":"Thermomechanical processing induced microstructural tuning for synergistic enhancement of structural and functional performance in WCu immiscible composite","authors":"Peng-Cheng Cai , Kai-Fei Wang , Guo-Hua Zhang , Kuo-Chih Chou","doi":"10.1016/j.ijrmhm.2026.107681","DOIUrl":"10.1016/j.ijrmhm.2026.107681","url":null,"abstract":"<div><div>W<img>Cu composites combine high strength, rigidity, and low thermal expansion coefficient of W with excellent electrical and thermal conductivity of Cu, endowing them with broad application prospects in a broad application. However, the intrinsic immiscibility between W and Cu leads weak interfacial bonding, posing a long-standing challenge to their high-performance applications. Although the introduction of a third component is widely recognized as an effective mean of improving interfacial compatibility, it is often achieved at the expense of electrical and thermal performance. In this study, fine-grained W<img>Cu composites were subjected to precisely tailored thermomechanical processing (rolling and annealing). On the one hand, the formation of heterointerface-induced stacking faults was promoted, and the substructures introduced by rolling enhanced the plastic deformability of the W particles. Through these coupled effects, load transfer and dislocation motion across the two phases were effectively regulated, leading to a pronounced improvement in overall mechanical performance. On the other hand, the continuity of the Cu phase was enhanced and charge transport pathways were optimized, thereby resulting in improvement of electrical conductivity. These findings provide new insights into the tuning of phase configurations in immiscible metal composites, offering a viable pathway for the synergistic optimization of multiple properties.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107681"},"PeriodicalIF":4.6,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995331","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 : 2026-01-14DOI: 10.1016/j.ijrmhm.2026.107674
Lei Chen , Xuejiao Sun , Yanbo Ding , Baochang Liu
In this study, the abrasive wear in open-structure polycrystalline diamond compact (PDC) thrust bearings was reduced by applying a shark skin-inspired rhombic grid texture to the bearing surface. The influence of the groove angle of the texture on the tribological performance of a PDC/Si₃N₄ pair was investigated under lubrication with a water-based drilling fluid. Friction tests revealed that a groove angle of 45° optimized tribological performance, enhancing surface wettability by 45.27% (contact angle: 36.45°) and reducing the coefficient of friction (COF) by 57.35% (COF: 0.07541). This texture formed a continuous lubricating film, trapped abrasive debris, and stored the drilling fluid. Thus, the three-body and adhesive wear were effectively mitigated, and the lubrication was enhanced. The biomimetic design presented a viable solution for extending the service life and reliability of diamond bearings in harsh downhole environments.
{"title":"Enhancing the tribological performance of polycrystalline diamond compact in water-based drilling fluids by mimicking the rhombic grid texture of shark skin","authors":"Lei Chen , Xuejiao Sun , Yanbo Ding , Baochang Liu","doi":"10.1016/j.ijrmhm.2026.107674","DOIUrl":"10.1016/j.ijrmhm.2026.107674","url":null,"abstract":"<div><div>In this study, the abrasive wear in open-structure polycrystalline diamond compact (PDC) thrust bearings was reduced by applying a shark skin-inspired rhombic grid texture to the bearing surface. The influence of the groove angle of the texture on the tribological performance of a PDC/Si₃N₄ pair was investigated under lubrication with a water-based drilling fluid. Friction tests revealed that a groove angle of 45° optimized tribological performance, enhancing surface wettability by 45.27% (contact angle: 36.45°) and reducing the coefficient of friction (COF) by 57.35% (COF: 0.07541). This texture formed a continuous lubricating film, trapped abrasive debris, and stored the drilling fluid. Thus, the three-body and adhesive wear were effectively mitigated, and the lubrication was enhanced. The biomimetic design presented a viable solution for extending the service life and reliability of diamond bearings in harsh downhole environments.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107674"},"PeriodicalIF":4.6,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035167","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 : 2026-01-13DOI: 10.1016/j.ijrmhm.2026.107665
Tianrun Ma , Fengshun Du , Bohua Duan , Dezhi Wang , Zhuangzhi Wu , Xinli Liu
The development of novel Mo alloys that combine high strength and toughness has been a critical goal in the research community. A co-reinforced Mo alloy was prepared through powder metallurgy by adding partially stabilized zirconia (PSZ) and MAX phase Ti3AlC2 to the Mo matrix. The influence of varying PSZ/Ti3AlC2 ratios on the microstructure and mechanical properties of Mo alloys was thoroughly studied. The results indicate that as the PSZ/ Ti3AlC2 ratio is increased, the density, elongation, and fracture toughness of sintered molybdenum alloys are enhanced, while their strength and hardness also show varying degrees of improvement. At a PSZ/Ti3AlC2 ratio of 7:3, the prepared Mo alloy exhibits optimal comprehensive properties, with a relative density of 96.8%, a hardness of 193.1 Hv, a tensile strength of 537.4 MPa, an elongation of 21.69%, and a fracture toughness of 29.1 MPa·m1/2. The synergistic effect of PSZ and Ti3AlC2 optimizes the alloy's microstructure and enhances its overall performance through multiple mechanisms. PSZ has a more pronounced effect on the ductility, whereas Ti3AlC2 plays a more significant role in enhancing the strength. The findings provide a new strategy for the preparation of high-performance molybdenum alloys.
{"title":"Microstructure and mechanical properties of Mo alloys reinforced with the combination of PSZ and Ti3AlC2","authors":"Tianrun Ma , Fengshun Du , Bohua Duan , Dezhi Wang , Zhuangzhi Wu , Xinli Liu","doi":"10.1016/j.ijrmhm.2026.107665","DOIUrl":"10.1016/j.ijrmhm.2026.107665","url":null,"abstract":"<div><div>The development of novel Mo alloys that combine high strength and toughness has been a critical goal in the research community. A co-reinforced Mo alloy was prepared through powder metallurgy by adding partially stabilized zirconia (PSZ) and MAX phase Ti<sub>3</sub>AlC<sub>2</sub> to the Mo matrix. The influence of varying PSZ/Ti<sub>3</sub>AlC<sub>2</sub> ratios on the microstructure and mechanical properties of Mo alloys was thoroughly studied. The results indicate that as the PSZ/ Ti<sub>3</sub>AlC<sub>2</sub> ratio is increased, the density, elongation, and fracture toughness of sintered molybdenum alloys are enhanced, while their strength and hardness also show varying degrees of improvement. At a PSZ/Ti<sub>3</sub>AlC<sub>2</sub> ratio of 7:3, the prepared Mo alloy exhibits optimal comprehensive properties, with a relative density of 96.8%, a hardness of 193.1 Hv, a tensile strength of 537.4 MPa, an elongation of 21.69%, and a fracture toughness of 29.1 MPa·m<sup>1/2</sup>. The synergistic effect of PSZ and Ti<sub>3</sub>AlC<sub>2</sub> optimizes the alloy's microstructure and enhances its overall performance through multiple mechanisms. PSZ has a more pronounced effect on the ductility, whereas Ti<sub>3</sub>AlC<sub>2</sub> plays a more significant role in enhancing the strength. The findings provide a new strategy for the preparation of high-performance molybdenum alloys.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107665"},"PeriodicalIF":4.6,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035166","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 : 2026-01-13DOI: 10.1016/j.ijrmhm.2026.107675
Tao Chen , Jianghuiqi Lan , Zhenhong Xing , Ziai Cao , Donghua Dai
To overcome the limited compressive properties of the difficult-to-process W-based porous components, a dual-laser powder bed fusion (DL-PBF) additive manufacturing was proposed to fabricate porous 98 W-TiC-Y2O3 composites based on the in-situ lack of fusion (LOF) induced porosities driven by the regulated melt flow-wetting behaviors. Influence of processing parameters on the pore morphology and distribution, element distribution, microstructure evolution, compression performance and energy absorption coefficient (η) of LOF-induced pores was studied. The randomly distributed closed pores would gradually transform into uniformly distributed connected pores for the application of the lower laser power, reducing the compressive strength due to the limited bearing region and more concentrated stress. As the laser power was reduced from 120 W to 60 W, the connected porosity was increased from 16.57% to 26.92% combined with the average LOF-induced pores size varying from 88.6 μm to 296.6 μm, decreasing the compressive strength from 735.4 MPa to 244.5 MPa. O element in nano-Y2O3 could promote the melt oxidation and hinder the melt spreading, which was beneficial for the formation of LOF-induced pores. Nano-Y2O3, acting as non-uniform nucleation sites, would synergistically refine grains within un-melted W particles in the loose layer into cellular substructures. Nano-TiC was decomposed into Ti and C atoms, which was solid dissolved in the W matrix. The collapse of LOF-induced pores, the fragmentation of W particles and the propagation of microcracks of the porous structures of the brittle 98 W during the compression test could efficiently enhance the energy dissipation, generating a high η of 54.7% at the low laser power of 60 W. Finally, 98 W porous structures with varying porosity ratio along the building direction was successfully produced free of the obvious layered transition interface.
{"title":"Dual laser-powder bed fusion additive manufacturing of difficult-to-process 98W composite porous structures: Porosity-microstructure evolution and compressive properties","authors":"Tao Chen , Jianghuiqi Lan , Zhenhong Xing , Ziai Cao , Donghua Dai","doi":"10.1016/j.ijrmhm.2026.107675","DOIUrl":"10.1016/j.ijrmhm.2026.107675","url":null,"abstract":"<div><div>To overcome the limited compressive properties of the difficult-to-process W-based porous components, a dual-laser powder bed fusion (DL-PBF) additive manufacturing was proposed to fabricate porous 98 W-TiC-Y2O3 composites based on the in-situ lack of fusion (LOF) induced porosities driven by the regulated melt flow-wetting behaviors. Influence of processing parameters on the pore morphology and distribution, element distribution, microstructure evolution, compression performance and energy absorption coefficient (<em>η</em>) of LOF-induced pores was studied. The randomly distributed closed pores would gradually transform into uniformly distributed connected pores for the application of the lower laser power, reducing the compressive strength due to the limited bearing region and more concentrated stress. As the laser power was reduced from 120 W to 60 W, the connected porosity was increased from 16.57% to 26.92% combined with the average LOF-induced pores size varying from 88.6 μm to 296.6 μm, decreasing the compressive strength from 735.4 MPa to 244.5 MPa. O element in nano-Y2O3 could promote the melt oxidation and hinder the melt spreading, which was beneficial for the formation of LOF-induced pores. Nano-Y2O3, acting as non-uniform nucleation sites, would synergistically refine grains within un-melted W particles in the loose layer into cellular substructures. Nano-TiC was decomposed into Ti and C atoms, which was solid dissolved in the W matrix. The collapse of LOF-induced pores, the fragmentation of W particles and the propagation of microcracks of the porous structures of the brittle 98 W during the compression test could efficiently enhance the energy dissipation, generating a high <em>η</em> of 54.7% at the low laser power of 60 W. Finally, 98 W porous structures with varying porosity ratio along the building direction was successfully produced free of the obvious layered transition interface.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107675"},"PeriodicalIF":4.6,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962533","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 : 2026-01-13DOI: 10.1016/j.ijrmhm.2026.107669
Puteri Noor Safura Megat Mahmud , Yoganash Putthisigamany , Megat Mohd Izhar Sapeli , Vidhya Selvanathan , Kazi Sajedur Rahman , Ubaidah Syafiq , Brahim Aissa , Mohammad Istiaque Hossain , Norasikin Ahmad Ludin , Puvaneswaran Chelvanathan
Uncontrolled diffusion and interfacial degradation at refractory metal back contacts remain major bottlenecks to improving the reliability and efficiency of thin film solar cells (TFSCs). This study investigates the structural, electrical, and interfacial properties of Mo thin films, MoW0.25 capping layers (MoW0.25 CL), and W capping layers (W CL) deposited on Mo back contacts via direct-current magnetron sputtering. Comprehensive structural, morphological, topographical, vibrational, and electrical analyses were performed to elucidate how W incorporation influences microstructure and electronic behaviour. The MoW0.25 CL exhibited the smoothest surface (Ra = 3.8 nm) and the highest work function (4.80 eV), which is associated with enhanced surface uniformity and modified electronic structure compared to pure Mo and W CL thin films. Upon selenization at 580 °C, the MoW0.25Se2 interfacial layer displays localized selenide formation with limited selenium penetration, indicating enhanced resistance to selenium diffusion relative to the Mo and W counterparts. The selenized MoW0.25 CL also achieves the low resistivity (58.8 μΩ cm) while maintaining high carrier concentration and mobility. Overall, the results demonstrate that controlled MoW alloying provides an effective strategy to tailor interfacial reactions and electronic properties of refractory back contacts in TFSCs, offering insights into the design of thermally stable metal/semiconductor interfaces for high-temperature electronic applications.
{"title":"Work function enhancement and interfacial diffusion behaviour of sputtered refractory MoW alloy thin films for back-contact engineering","authors":"Puteri Noor Safura Megat Mahmud , Yoganash Putthisigamany , Megat Mohd Izhar Sapeli , Vidhya Selvanathan , Kazi Sajedur Rahman , Ubaidah Syafiq , Brahim Aissa , Mohammad Istiaque Hossain , Norasikin Ahmad Ludin , Puvaneswaran Chelvanathan","doi":"10.1016/j.ijrmhm.2026.107669","DOIUrl":"10.1016/j.ijrmhm.2026.107669","url":null,"abstract":"<div><div>Uncontrolled diffusion and interfacial degradation at refractory metal back contacts remain major bottlenecks to improving the reliability and efficiency of thin film solar cells (TFSCs). This study investigates the structural, electrical, and interfacial properties of Mo thin films, Mo<img>W<sub>0.25</sub> capping layers (Mo<img>W<sub>0.25</sub> CL), and W capping layers (W CL) deposited on Mo back contacts via direct-current magnetron sputtering. Comprehensive structural, morphological, topographical, vibrational, and electrical analyses were performed to elucidate how W incorporation influences microstructure and electronic behaviour. The Mo<img>W<sub>0.25</sub> CL exhibited the smoothest surface (Ra = 3.8 nm) and the highest work function (4.80 eV), which is associated with enhanced surface uniformity and modified electronic structure compared to pure Mo and W CL thin films. Upon selenization at 580 °C, the Mo<img>W<sub>0.25</sub>Se<sub>2</sub> interfacial layer displays localized selenide formation with limited selenium penetration, indicating enhanced resistance to selenium diffusion relative to the Mo and W counterparts. The selenized Mo<img>W<sub>0.25</sub> CL also achieves the low resistivity (58.8 μΩ cm) while maintaining high carrier concentration and mobility. Overall, the results demonstrate that controlled Mo<img>W alloying provides an effective strategy to tailor interfacial reactions and electronic properties of refractory back contacts in TFSCs, offering insights into the design of thermally stable metal/semiconductor interfaces for high-temperature electronic applications.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107669"},"PeriodicalIF":4.6,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962419","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 : 2026-01-13DOI: 10.1016/j.ijrmhm.2026.107676
Chenguang Guo , Xingyu Li , En Mei , Junming Liu , Hao Xu , Yuan Chao , Peng Zhang , Zhongyou Que , Lin Zhang , Mingli Qin , Xuanhui Qu
Carbides as typical secondary particles are effective in strengthening tungsten (W) alloys, particularly at elevated temperatures. However, the addition of carbides generally necessitates a higher sintering temperature for W in the powder metallurgy process, resulting in coarsened microstructures and degraded properties. In this study, W-HfC composite nanopowders with a core-shell structure are prepared by a freeze-drying method to overcome the densification barrier caused by HfC during subsequent sintering. The constant-heating-rate sintering experiments demonstrate that the sintering kinetics are independent of HfC content for W-HfC core-shell nanopowders. Utilizing a pressureless two-step sintering (TSS) method at low temperatures, we fabricated a dense W-0.5 wt% HfC alloy with an ultrafine-grained microstructure (average grain size: 420 nm). Benefitting from low-temperature sintering, HfC particles with sizes below 20 nm are uniformly dispersed within the W matrix and exert a significant strengthening effect on W. This study demonstrates that freeze-drying combined with TSS is a promising method for fabricating dispersion-strengthened W alloys with well-controlled microstructure and properties.
{"title":"Low-temperature sintering of W-HfC core-shell powders for microstructure regulation","authors":"Chenguang Guo , Xingyu Li , En Mei , Junming Liu , Hao Xu , Yuan Chao , Peng Zhang , Zhongyou Que , Lin Zhang , Mingli Qin , Xuanhui Qu","doi":"10.1016/j.ijrmhm.2026.107676","DOIUrl":"10.1016/j.ijrmhm.2026.107676","url":null,"abstract":"<div><div>Carbides as typical secondary particles are effective in strengthening tungsten (W) alloys, particularly at elevated temperatures. However, the addition of carbides generally necessitates a higher sintering temperature for W in the powder metallurgy process, resulting in coarsened microstructures and degraded properties. In this study, W-HfC composite nanopowders with a core-shell structure are prepared by a freeze-drying method to overcome the densification barrier caused by HfC during subsequent sintering. The constant-heating-rate sintering experiments demonstrate that the sintering kinetics are independent of HfC content for W-HfC core-shell nanopowders. Utilizing a pressureless two-step sintering (TSS) method at low temperatures, we fabricated a dense W-0.5 wt% HfC alloy with an ultrafine-grained microstructure (average grain size: 420 nm). Benefitting from low-temperature sintering, HfC particles with sizes below 20 nm are uniformly dispersed within the W matrix and exert a significant strengthening effect on W. This study demonstrates that freeze-drying combined with TSS is a promising method for fabricating dispersion-strengthened W alloys with well-controlled microstructure and properties.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107676"},"PeriodicalIF":4.6,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962417","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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