Pub Date : 2026-01-12DOI: 10.1016/j.ijrmhm.2026.107673
Jun Yang, Yanhang Shi, Liu He, Wei Wang, Guomin Le, Xinjian Zhang
The elevated cost of spherical tantalum powder utilized in additive manufacturing significantly hinders the development and application of tantalum components. In this study, three sets of tantalum thin-wall samples were fabricated using laser melting deposition (LMD) with varying laser power settings, employing non-spherical tantalum powder as the raw material. The samples were analyzed for their scanning electron microscopy (SEM) morphology, phase composition, density, hardness, mechanical properties, and impurity content. The findings indicate that the tantalum components produced via LMD exhibit columnar grains oriented along the deposition direction, achieving a high density of up to 98.7%. The LMD-fabricated tantalum components demonstrate moderate mechanical properties and elongation rate. This study demonstrates that non-spherical tantalum powder can be effectively utilized to produce tantalum components with superior performance through LMD. This approach offers a novel and cost-effective method for the preparation of tantalum components, which holds significant potential for the widespread adoption and application of tantalum.
{"title":"Microstructure and properties of tantalum deposited by laser melting deposition using non-spherical tantalum powder","authors":"Jun Yang, Yanhang Shi, Liu He, Wei Wang, Guomin Le, Xinjian Zhang","doi":"10.1016/j.ijrmhm.2026.107673","DOIUrl":"10.1016/j.ijrmhm.2026.107673","url":null,"abstract":"<div><div>The elevated cost of spherical tantalum powder utilized in additive manufacturing significantly hinders the development and application of tantalum components. In this study, three sets of tantalum thin-wall samples were fabricated using laser melting deposition (LMD) with varying laser power settings, employing non-spherical tantalum powder as the raw material. The samples were analyzed for their scanning electron microscopy (SEM) morphology, phase composition, density, hardness, mechanical properties, and impurity content. The findings indicate that the tantalum components produced via LMD exhibit columnar grains oriented along the deposition direction, achieving a high density of up to 98.7%. The LMD-fabricated tantalum components demonstrate moderate mechanical properties and elongation rate. This study demonstrates that non-spherical tantalum powder can be effectively utilized to produce tantalum components with superior performance through LMD. This approach offers a novel and cost-effective method for the preparation of tantalum components, which holds significant potential for the widespread adoption and application of tantalum.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"138 ","pages":"Article 107673"},"PeriodicalIF":4.6,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956986","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 : 2026-01-10DOI: 10.1016/j.ijrmhm.2026.107670
Liangliang Zhang , Shalong Li , Meng Zhang , Kunying Li , Jiayuan Zhao , Pengjun Zuo , Jiaen Yu , Zhuoran Shi , Qingjun Zhang , Jiahao Zhang , Shifeng Liu
The high-quality joining of laser beam welding (LBW) molybdenum (Mo) alloy joints is confronted with challenges due to the reduction of embrittlement and strength. On this study, An innovative approach “nitrogen (N) and titanium (Ti) combined alloy” was employed in the laser welding of molybdenum alloys, which resulted in a significant enhancement in joint strength while maintaining ductility. This method is achieved through the N2 alloying meanwhile addition Ti to the melt pool. The essential cause of the grain boundary embrittlement is the O easily forms the lamellar MoO2 at the Mo grain boundaries, which leads to the low bonding strength of the grain boundary. The strengthening mechanism of the N and Ti combined alloying is attributed to the purification effect of N and Ti on grain boundaries and the strengthening effect of the second phase formed by their reaction at grain boundaries. Firstly, Ti reacts with MoO2 to form TiO2, thereby purifying the grain boundaries. Secondly, N can react with Ti in the high - temperature melt pool forming approximately 100 nm TiN particles, which are distributed both in the grains and at the grain boundaries. They can prevent the formation of dislocations and inhibit crack propagation along the grain boundaries, thus strengthening the grain boundaries.
{"title":"Study on the strengthening mechanism of nitrogen–titanium combination alloying for laser beam welding joint of molybdenum alloy","authors":"Liangliang Zhang , Shalong Li , Meng Zhang , Kunying Li , Jiayuan Zhao , Pengjun Zuo , Jiaen Yu , Zhuoran Shi , Qingjun Zhang , Jiahao Zhang , Shifeng Liu","doi":"10.1016/j.ijrmhm.2026.107670","DOIUrl":"10.1016/j.ijrmhm.2026.107670","url":null,"abstract":"<div><div>The high-quality joining of laser beam welding (LBW) molybdenum (Mo) alloy joints is confronted with challenges due to the reduction of embrittlement and strength. On this study, An innovative approach “nitrogen (N) and titanium (Ti) combined alloy” was employed in the laser welding of molybdenum alloys, which resulted in a significant enhancement in joint strength while maintaining ductility. This method is achieved through the N<sub>2</sub> alloying meanwhile addition Ti to the melt pool. The essential cause of the grain boundary embrittlement is the O easily forms the lamellar MoO<sub>2</sub> at the Mo grain boundaries, which leads to the low bonding strength of the grain boundary. The strengthening mechanism of the N and Ti combined alloying is attributed to the purification effect of N and Ti on grain boundaries and the strengthening effect of the second phase formed by their reaction at grain boundaries. Firstly, Ti reacts with MoO<sub>2</sub> to form TiO<sub>2</sub>, thereby purifying the grain boundaries. Secondly, N can react with Ti in the high - temperature melt pool forming approximately 100 nm TiN particles, which are distributed both in the grains and at the grain boundaries. They can prevent the formation of dislocations and inhibit crack propagation along the grain boundaries, thus strengthening the grain boundaries.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107670"},"PeriodicalIF":4.6,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979484","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 : 2026-01-09DOI: 10.1016/j.ijrmhm.2026.107671
Ravi Ranjan Kumar , Kartikey Sharma , Varsha Florist , Namit Pai , Debasis Tripathy , S.V.S. Narayana Murty
Niobium alloy C-103 is the lightest among the refractory alloy family and is widely used for high temperature applications in aerospace propulsion systems. In the present study, sheets of 2 × 1000 × 1000 mm were processed through cold rolling. However, the cold rolled sheets exhibited higher strength with a significant reduction in percentage elongation (ductility), making them unsuitable for further cold forming process, such as the fabrication of divergent sections of rocket engines. In order to eliminate the residual stresses and obtain a strain-free microstructure, the cold rolled sheets have been vacuum annealed at varying temperatures of 1100 °C, 1200 °C and 1300 °C for 1, 2 and 4 h. Detailed microstructural analysis and mechanical properties evaluation has been carried out on vacuum annealed samples for arriving at optimum annealing parameters. It is noted that the samples annealed at 1100 °C had remnant elongated grains, whereas coarsening of grains was noticed for samples annealed at 1300 °C for 4 h. The samples annealed at 1200 °C for 2 and 4 h had an optimum grain size of 33 and 39 μm, respectively. The corresponding 0.2 % yield strength, ultimate tensile strength and % elongation for 2 h and 4 h condition was 276 ± 4.4 MPa, 385 ± 3.5 MPa, 39.6 ± 3.1% and 271 ± 1.8 MPa, 388 ± 1.5 MPa, 37.8 ± 1%, respectively. Further, an attempt has been made to understand the grain growth kinetics with respect to variation in annealing temperatures and time. The activation energy was estimated to be 792 kJ/mol in the temperature range of 1100–1300 °C for this alloy. The 0.2% yield strength of C-103 material was further correlated to the grain size, as per Hall-Petch relation and the values of σ0 (lattice friction resistance constant) and k0 (grain boundary barrier constant) were estimated to be 210 MPa and 356 MPa, respectively.
{"title":"Effect of vacuum annealing temperature and time on the recrystallisation behavior of cold rolled niobium alloy C-103 sheets","authors":"Ravi Ranjan Kumar , Kartikey Sharma , Varsha Florist , Namit Pai , Debasis Tripathy , S.V.S. Narayana Murty","doi":"10.1016/j.ijrmhm.2026.107671","DOIUrl":"10.1016/j.ijrmhm.2026.107671","url":null,"abstract":"<div><div>Niobium alloy C-103 is the lightest among the refractory alloy family and is widely used for high temperature applications in aerospace propulsion systems. In the present study, sheets of 2 × 1000 × 1000 mm were processed through cold rolling. However, the cold rolled sheets exhibited higher strength with a significant reduction in percentage elongation (ductility), making them unsuitable for further cold forming process, such as the fabrication of divergent sections of rocket engines. In order to eliminate the residual stresses and obtain a strain-free microstructure, the cold rolled sheets have been vacuum annealed at varying temperatures of 1100 °C, 1200 °C and 1300 °C for 1, 2 and 4 h. Detailed microstructural analysis and mechanical properties evaluation has been carried out on vacuum annealed samples for arriving at optimum annealing parameters. It is noted that the samples annealed at 1100 °C had remnant elongated grains, whereas coarsening of grains was noticed for samples annealed at 1300 °C for 4 h. The samples annealed at 1200 °C for 2 and 4 h had an optimum grain size of 33 and 39 μm, respectively. The corresponding 0.2 % yield strength, ultimate tensile strength and % elongation for 2 h and 4 h condition was 276 ± 4.4 MPa, 385 ± 3.5 MPa, 39.6 ± 3.1% and 271 ± 1.8 MPa, 388 ± 1.5 MPa, 37.8 ± 1%, respectively. Further, an attempt has been made to understand the grain growth kinetics with respect to variation in annealing temperatures and time. The activation energy was estimated to be 792 kJ/mol in the temperature range of 1100–1300 °C for this alloy. The 0.2% yield strength of C-103 material was further correlated to the grain size, as per Hall-Petch relation and the values of σ<sub>0</sub> (lattice friction resistance constant) and k<sub>0</sub> (grain boundary barrier constant) were estimated to be 210 MPa and 356 MPa<span><math><msqrt><mrow><mi>μ</mi><mi>m</mi></mrow></msqrt></math></span>, respectively.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107671"},"PeriodicalIF":4.6,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979059","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}
In the present study, the oxidation behavior of WC-12Co prepared by mechanical milling and spark plasma sintering was investigated in dry air (DA) and water vapor (WV) atmospheres at 400–800 °C. The results indicated that the oxidation rate increased significantly with increasing temperature, and the oxidation was significantly accelerated in water vapor compared to dry air. The Vickers hardness decreased after high-temperature exposure, which was influenced by the alterations in structural integrity observed in the material. The formation of Co3O4, WO3, and CoWO4 oxides was observed with distinct morphological changes at elevated temperatures. As the temperature increased, the oxide layer became thicker and more porous, with the appearance of cracks. Enhanced porosity facilitated pore link formation, serving as diffusion pathways for oxygen, water vapor, and metal ions. Notably, oxidation in a water vapor atmosphere resulted in a thicker and more porous oxide layer compared to that in dry air, driven by the release of additional H2 gas alongside CO2/CO and other volatile species. This study provides valuable insights into the oxidation mechanisms of WC-12Co at high-temperatures, offering critical implications for its application in cutting tools and wear-resistant components.
{"title":"High-temperature oxidation behavior of WC-12Co cemented carbide in dry air and water vapor atmospheres","authors":"Bambang Hermanto , Resetiana Dwi Desiati , Wahyu Bambang Widayatno , Myrna Ariati Mochtar , Bambang Suharno , Toto Sudiro","doi":"10.1016/j.ijrmhm.2026.107664","DOIUrl":"10.1016/j.ijrmhm.2026.107664","url":null,"abstract":"<div><div>In the present study, the oxidation behavior of WC-12Co prepared by mechanical milling and spark plasma sintering was investigated in dry air (DA) and water vapor (WV) atmospheres at 400–800 °C. The results indicated that the oxidation rate increased significantly with increasing temperature, and the oxidation was significantly accelerated in water vapor compared to dry air. The Vickers hardness decreased after high-temperature exposure, which was influenced by the alterations in structural integrity observed in the material. The formation of Co<sub>3</sub>O<sub>4</sub>, WO<sub>3</sub>, and CoWO<sub>4</sub> oxides was observed with distinct morphological changes at elevated temperatures. As the temperature increased, the oxide layer became thicker and more porous, with the appearance of cracks. Enhanced porosity facilitated pore link formation, serving as diffusion pathways for oxygen, water vapor, and metal ions. Notably, oxidation in a water vapor atmosphere resulted in a thicker and more porous oxide layer compared to that in dry air, driven by the release of additional H<sub>2</sub> gas alongside CO<sub>2</sub>/CO and other volatile species. This study provides valuable insights into the oxidation mechanisms of WC-12Co at high-temperatures, offering critical implications for its application in cutting tools and wear-resistant components.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107664"},"PeriodicalIF":4.6,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979057","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 : 2026-01-05DOI: 10.1016/j.ijrmhm.2026.107655
Xiuyuan Yin , Xinxing Li , Hu Sun , Ning Ding , Lei Ren , Hongqi Shi , Hongxia Wang , Jing Liang , Changsheng Liu
During the rapid solidification of laser melting deposition, poor melt pool fluidity in NbSi based alloys results in insufficient pore wetting and filling, significantly degrading the mechanical properties. To address this issue, controlled addition of rare earth Yttrium (Y) was utilized to improve melt fluidity, thereby enhancing the density of the deposited layer and optimizing mechanical properties. Results show that an appropriate Y (0.15 at.%) addition increased sample density from 99.83 % to 99.97 %. Y addition did not alter the primary phase constituents of the alloy, which remained Nbss, α-Nb5Si3, and γ-Nb5Si3 phases, but it affected the phase fractions. With the increase of Y content, the total silicide content increased in the alloys, alongside the precipitation of more nanoscale Y2O3 and γ-Nb5Si3 phases. The alloy with 0.15 at.% Y addition achieved maximum fracture toughness of 15.13 MPa·m1/2 due to microstructure refinement and compactness improvement. For compressive strength, a continuous enhancement was observed up to 2358.9 MPa in alloys with 1.0 at.% Y addition, which was attributed to increased silicide content, the enhanced solid solubility of Y in the Nbss phase, and the increased content of nanoscale Y2O3 and γ-Nb5Si3 precipitates.
{"title":"Fine microstructure, better compactness, and significant fracture toughness of multi-component Nb–Si based alloy by an appropriate amount of Yttrium addition during the laser melting deposition","authors":"Xiuyuan Yin , Xinxing Li , Hu Sun , Ning Ding , Lei Ren , Hongqi Shi , Hongxia Wang , Jing Liang , Changsheng Liu","doi":"10.1016/j.ijrmhm.2026.107655","DOIUrl":"10.1016/j.ijrmhm.2026.107655","url":null,"abstract":"<div><div>During the rapid solidification of laser melting deposition, poor melt pool fluidity in Nb<img>Si based alloys results in insufficient pore wetting and filling, significantly degrading the mechanical properties. To address this issue, controlled addition of rare earth Yttrium (Y) was utilized to improve melt fluidity, thereby enhancing the density of the deposited layer and optimizing mechanical properties. Results show that an appropriate Y (0.15 at.%) addition increased sample density from 99.83 % to 99.97 %. Y addition did not alter the primary phase constituents of the alloy, which remained Nbss, α-Nb<sub>5</sub>Si<sub>3</sub>, and γ-Nb<sub>5</sub>Si<sub>3</sub> phases, but it affected the phase fractions. With the increase of Y content, the total silicide content increased in the alloys, alongside the precipitation of more nanoscale Y<sub>2</sub>O<sub>3</sub> and γ-Nb<sub>5</sub>Si<sub>3</sub> phases. The alloy with 0.15 at.% Y addition achieved maximum fracture toughness of 15.13 MPa·m<sup>1/2</sup> due to microstructure refinement and compactness improvement. For compressive strength, a continuous enhancement was observed up to 2358.9 MPa in alloys with 1.0 at.% Y addition, which was attributed to increased silicide content, the enhanced solid solubility of Y in the Nbss phase, and the increased content of nanoscale Y<sub>2</sub>O<sub>3</sub> and γ-Nb<sub>5</sub>Si<sub>3</sub> precipitates.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107655"},"PeriodicalIF":4.6,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979058","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 : 2026-01-05DOI: 10.1016/j.ijrmhm.2026.107654
Zihan Yang , Ruochong Wang , Huixia Li , Yafeng Yang , Yong Liu , Weiwei He
With the developments of deep mining and oiling, the rotary drilling bit encounter the urgent requirements of high wear resistance and structural-functional integration. In this work, EB-PBF (Electron beam powder bed fusion) was utilized to fabricate CuNiFeSnTi/WC/diamond composites for drilling matrix body. The dissolution and precipitation of carbides, and their effects on the grain refinement of CuNiFeSnTi alloy were investigated. The results demonstrated that the dissolution of cast tungsten carbide, resulting in detached cast tungsten carbide particles and (Ti,W)C1-x precipitates, refined the grains by the grain boundary pinning and heterogeneous nucleation. The EB-PBFed composites show satisfactory mechanical properties of 667.08 ± 20.51 MPa and excellent wear resistance properties at E = 36 J/mm3. The drilling matrix body made of CuNiFeSnTi/WC/diamond composites can enhance body durability and hence protection of polycrystalline diamond compact cutters.
{"title":"Effect of WC on grain refinement of binder alloy in EB-PBFed CuNiFeSnTi/WC/diamond composites","authors":"Zihan Yang , Ruochong Wang , Huixia Li , Yafeng Yang , Yong Liu , Weiwei He","doi":"10.1016/j.ijrmhm.2026.107654","DOIUrl":"10.1016/j.ijrmhm.2026.107654","url":null,"abstract":"<div><div>With the developments of deep mining and oiling, the rotary drilling bit encounter the urgent requirements of high wear resistance and structural-functional integration. In this work, EB-PBF (Electron beam powder bed fusion) was utilized to fabricate CuNiFeSnTi/WC/diamond composites for drilling matrix body. The dissolution and precipitation of carbides, and their effects on the grain refinement of CuNiFeSnTi alloy were investigated. The results demonstrated that the dissolution of cast tungsten carbide, resulting in detached cast tungsten carbide particles and (Ti,W)C<sub>1-x</sub> precipitates, refined the grains by the grain boundary pinning and heterogeneous nucleation. The EB-PBFed composites show satisfactory mechanical properties of 667.08 ± 20.51 MPa and excellent wear resistance properties at <em>E</em> = 36 J/mm<sup>3</sup>. The drilling matrix body made of CuNiFeSnTi/WC/diamond composites can enhance body durability and hence protection of polycrystalline diamond compact cutters.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107654"},"PeriodicalIF":4.6,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145903349","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 : 2026-01-03DOI: 10.1016/j.ijrmhm.2026.107652
Ziqing Xiong , Xiufang Gong , Xiaohu Yuan , Chunmei Tang , Xia Lou , Xiangrong Li , Kaifeng Jing , Longgang Wang , Jinwen Cai , Xiang Xia , Tianen Yang , Guang Xian , Zhixing Guo
Carbide-metal cermet materials-(WC-6Ni) were fabricated, and the effect of tungsten boride (WB) addition on the phase evolution, microstructure, mechanical properties, and wear behavior was investigated. The results show that the microstructure of the cermet materials is changed after the addition of WB. With the WB addition, WC grains are first coarsened at 0.5 wt% WB, and then refined at 0.9 wt% WB, while the grains become rounder and more homogeneous. During sintering, WB reacts with the Ni binder to form the intermetallic compound Ni2B. Meanwhile, a small amount of boron dissolves into the WC lattice, and a lattice distortion is induced. In addition, the proportion of high-angle grain boundaries in the WC phase increases, and the {0001} basal texture is strengthened. In the Ni phase, the geometrically necessary dislocation (GND) density rises, indicating enhanced local strain hardening. The Schmid factor (SF) decreases, suggesting suppressed slip activity and improved resistance to plastic deformation. As a consequence, both the mechanical and tribological properties have been improved. The composite containing 0.5 wt% WB shows the highest hardness and adequate toughness. The coefficient of friction (COF) and wear rate decrease, indicating better wear resistance under both room-temperature and high-temperature conditions.
{"title":"Microstructure and wear behavior of carbide-metal cermet materials with WB addition","authors":"Ziqing Xiong , Xiufang Gong , Xiaohu Yuan , Chunmei Tang , Xia Lou , Xiangrong Li , Kaifeng Jing , Longgang Wang , Jinwen Cai , Xiang Xia , Tianen Yang , Guang Xian , Zhixing Guo","doi":"10.1016/j.ijrmhm.2026.107652","DOIUrl":"10.1016/j.ijrmhm.2026.107652","url":null,"abstract":"<div><div>Carbide-metal cermet materials-(WC-6Ni) were fabricated, and the effect of tungsten boride (WB) addition on the phase evolution, microstructure, mechanical properties, and wear behavior was investigated. The results show that the microstructure of the cermet materials is changed after the addition of WB. With the WB addition, WC grains are first coarsened at 0.5 wt% WB, and then refined at 0.9 wt% WB, while the grains become rounder and more homogeneous. During sintering, WB reacts with the Ni binder to form the intermetallic compound Ni<sub>2</sub>B. Meanwhile, a small amount of boron dissolves into the WC lattice, and a lattice distortion is induced. In addition, the proportion of high-angle grain boundaries in the WC phase increases, and the {0001} basal texture is strengthened. In the Ni phase, the geometrically necessary dislocation (GND) density rises, indicating enhanced local strain hardening. The Schmid factor (SF) decreases, suggesting suppressed slip activity and improved resistance to plastic deformation. As a consequence, both the mechanical and tribological properties have been improved. The composite containing 0.5 wt% WB shows the highest hardness and adequate toughness. The coefficient of friction (COF) and wear rate decrease, indicating better wear resistance under both room-temperature and high-temperature conditions.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107652"},"PeriodicalIF":4.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894146","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 : 2026-01-03DOI: 10.1016/j.ijrmhm.2026.107651
Haowei Deng , Zibin Zou , Bin Du, Tao Zhang
Tungsten (W) has been recognized as a promising plasma-facing material for fusion reactors; however, its practical application is hindered by intrinsic brittleness, limited thermal shock resistance, and insufficient high-temperature stability. In this study, four composite systems—W-ZrC, W-Ti-ZrC, W-HEC, and W-Ti-HEC—were fabricated to systematically investigate their microstructural evolution, thermal shock response, mechanical properties, and thermal stability. Results demonstrate that Ti addition effectively refines the tungsten grain size while scavenging carbon from secondary phases to form Ti-C-O along with ZrO or HEC-O structures, thereby enhancing alloy hardness. In contrast, HEC addition increases the fraction of low-angle grain boundaries, which further rises upon thermal shock. Although all alloys exhibited mechanical degradation after thermal cycling, only W-HEC preserved compressive fracture strain both before and after thermal shock and showed superior thermal stability at elevated temperatures. These findings highlight the distinct roles of Ti and HEC in tailoring grain structure, defect evolution, and high-temperature performance of tungsten-based composites, offering critical insights into the design of advanced plasma-facing materials for fusion applications.
钨(W)被认为是一种很有前途的面向等离子体的聚变反应堆材料；但其固有脆性、抗热震性有限、高温稳定性不足，阻碍了其实际应用。本研究制备了w - zrc、W-Ti-ZrC、W-HEC和w - ti - hec四种复合材料体系，系统地研究了它们的显微组织演变、热冲击响应、力学性能和热稳定性。结果表明，Ti的加入可以有效细化钨的晶粒尺寸，同时清除二次相中的碳，形成Ti- c - o和ZrO或HEC-O组织，从而提高合金的硬度。相反，HEC的加入增加了低角晶界的比例，并且在热冲击下进一步增加。尽管所有合金在热循环后都表现出机械退化，但只有W-HEC在热冲击前后都保留了压缩断裂应变，并在高温下表现出优异的热稳定性。这些发现强调了Ti和HEC在调整钨基复合材料的晶粒结构、缺陷演变和高温性能方面的独特作用，为设计用于聚变应用的先进等离子体表面材料提供了重要见解。
{"title":"Thermal shock induced evolution of microstructure and mechanical properties in ultrafine-grained tungsten alloys","authors":"Haowei Deng , Zibin Zou , Bin Du, Tao Zhang","doi":"10.1016/j.ijrmhm.2026.107651","DOIUrl":"10.1016/j.ijrmhm.2026.107651","url":null,"abstract":"<div><div>Tungsten (W) has been recognized as a promising plasma-facing material for fusion reactors; however, its practical application is hindered by intrinsic brittleness, limited thermal shock resistance, and insufficient high-temperature stability. In this study, four composite systems—W-ZrC, W-Ti-ZrC, W-HEC, and W-Ti-HEC—were fabricated to systematically investigate their microstructural evolution, thermal shock response, mechanical properties, and thermal stability. Results demonstrate that Ti addition effectively refines the tungsten grain size while scavenging carbon from secondary phases to form Ti-C-O along with ZrO or HEC-O structures, thereby enhancing alloy hardness. In contrast, HEC addition increases the fraction of low-angle grain boundaries, which further rises upon thermal shock. Although all alloys exhibited mechanical degradation after thermal cycling, only W-HEC preserved compressive fracture strain both before and after thermal shock and showed superior thermal stability at elevated temperatures. These findings highlight the distinct roles of Ti and HEC in tailoring grain structure, defect evolution, and high-temperature performance of tungsten-based composites, offering critical insights into the design of advanced plasma-facing materials for fusion applications.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107651"},"PeriodicalIF":4.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894144","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 : 2026-01-03DOI: 10.1016/j.ijrmhm.2026.107653
A. Zamani Alishah, M. Baniasadi, G. Faraji
Tungsten–copper (WCu) composites are widely applied in electrical and thermal management systems, yet conventional fabrication methods are often constrained by incomplete densification, weak interfacial bonding, anisotropy, and the well-known trade-off between hardness and electrical conductivity. In this study, a novel entangled fiber plasma sintering (ETFPS) approach was employed to fabricate bicontinuous W50Cu composite. The method involves crumpling Cu and W fibers into highly entangled three-dimensional architectures, followed by compaction and consolidation via spark plasma sintering (SPS). This process ensures intimate interfacial contact, suppresses void formation, and promotes effective metallurgical bonding. Microstructural analysis revealed excellent bonding across CuCu, CuW, and even WW interfaces, accompanied by nearly full densification (∼99.84 % relative density). Remarkably, these results were achieved at far lower pressure (40 MPa) and temperature than conventional powder-based or high-temperature processing routes. The isotropic fiber arrangement generated by ETFPS suppressed preferential alignment, leading to uniform properties along different directions. Hardness values were measured as 383.4 HV in the radial direction (RD) and 409.3 HV in the axial direction (AD), with only ∼6 % variation. Similarly, electrical conductivity reached 65.3 % IACS (RD) and 64.4 % IACS (AD), differing by just 1.4 %. The results highlight ETFPS as a versatile and efficient route for producing isotropic W50Cu composites with superior multifunctional performance.
{"title":"Processing and characterization of bicontinuous W50Cu composite produced by entangled fiber plasma sintering (ETFPS) route","authors":"A. Zamani Alishah, M. Baniasadi, G. Faraji","doi":"10.1016/j.ijrmhm.2026.107653","DOIUrl":"10.1016/j.ijrmhm.2026.107653","url":null,"abstract":"<div><div>Tungsten–copper (W<img>Cu) composites are widely applied in electrical and thermal management systems, yet conventional fabrication methods are often constrained by incomplete densification, weak interfacial bonding, anisotropy, and the well-known trade-off between hardness and electrical conductivity. In this study, a novel entangled fiber plasma sintering (ETFPS) approach was employed to fabricate bicontinuous W<img>50Cu composite. The method involves crumpling Cu and W fibers into highly entangled three-dimensional architectures, followed by compaction and consolidation via spark plasma sintering (SPS). This process ensures intimate interfacial contact, suppresses void formation, and promotes effective metallurgical bonding. Microstructural analysis revealed excellent bonding across Cu<img>Cu, Cu<img>W, and even W<img>W interfaces, accompanied by nearly full densification (∼99.84 % relative density). Remarkably, these results were achieved at far lower pressure (40 MPa) and temperature than conventional powder-based or high-temperature processing routes. The isotropic fiber arrangement generated by ETFPS suppressed preferential alignment, leading to uniform properties along different directions. Hardness values were measured as 383.4 HV in the radial direction (RD) and 409.3 HV in the axial direction (AD), with only ∼6 % variation. Similarly, electrical conductivity reached 65.3 % IACS (RD) and 64.4 % IACS (AD), differing by just 1.4 %. The results highlight ETFPS as a versatile and efficient route for producing isotropic W<img>50Cu composites with superior multifunctional performance.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107653"},"PeriodicalIF":4.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894145","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 : 2026-01-02DOI: 10.1016/j.ijrmhm.2025.107649
Guoqiang Wang , Lihua Guo , Feng Zhang , Luqiao Yang , Jun Lin
Tungsten (W)-based cermet fuels have garnered significant interest in nuclear thermal propulsion (NTP) systems due to their high melting point, thermal properties, and compatibility with hydrogen (H2) propellants. The W–Y2O3 composite matrix prepared by spark plasma sintering (SPS) exhibits greater densification and suppressed grain growth compared to pure W. Since NTP systems operate at temperatures above 2300 °C, the microstructural evolution under elevated temperatures is crucial to fuel performance. This study investigates the high temperature effects on the microstructure of pure W and W–Y2O3 matrices fabricated by SPS. The matrices were subjected to temperatures ranging from 1800 °C to 2300 °C. Below 2300 °C, Y2O3 particles effectively inhibited W grain growth through the Zener pinning effect, thereby increasing the proportion of low-angle grain boundaries (LAGBs). At high temperatures, H₂ diffuses into the matrix, reacting with uranium dioxide (UO2), which contributes to fuel loss. The fine grains increase grain boundary density, extending H₂ diffusion paths, while LAGBs help mitigate harmful H₂ accumulation. However, at 2300 °C, W diffuses into Y2O3, causing the Y2O3 grains to grow and leading to the formation of pores and cracks. This weakens the Zener pinning effect, promoting abnormal grain growth of W, which ultimately results in an increase in high-angle grain boundaries (HAGBs) and accelerates the diffusion of H2. The study identifies three stages of W diffusion into Y2O3: initial enrichment at Y2O3 grain boundaries, formation of W-depleted/W-enriched island-like structures within Y2O3 grains, and the formation of a Y6WO12 core-Y2O3 shell structure at 2300 °C, providing valuable insights for optimizing Y2O3 composites for NTP applications.
{"title":"Microstructural evolution and transformation mechanisms of W and W-Y2O3 matrices under ultra-high temperature for nuclear thermal propulsion","authors":"Guoqiang Wang , Lihua Guo , Feng Zhang , Luqiao Yang , Jun Lin","doi":"10.1016/j.ijrmhm.2025.107649","DOIUrl":"10.1016/j.ijrmhm.2025.107649","url":null,"abstract":"<div><div>Tungsten (W)-based cermet fuels have garnered significant interest in nuclear thermal propulsion (NTP) systems due to their high melting point, thermal properties, and compatibility with hydrogen (H<sub>2</sub>) propellants. The W–Y<sub>2</sub>O<sub>3</sub> composite matrix prepared by spark plasma sintering (SPS) exhibits greater densification and suppressed grain growth compared to pure W. Since NTP systems operate at temperatures above 2300 °C, the microstructural evolution under elevated temperatures is crucial to fuel performance. This study investigates the high temperature effects on the microstructure of pure W and W–Y<sub>2</sub>O<sub>3</sub> matrices fabricated by SPS. The matrices were subjected to temperatures ranging from 1800 °C to 2300 °C. Below 2300 °C, Y<sub>2</sub>O<sub>3</sub> particles effectively inhibited W grain growth through the Zener pinning effect, thereby increasing the proportion of low-angle grain boundaries (LAGBs). At high temperatures, H₂ diffuses into the matrix, reacting with uranium dioxide (UO<sub>2</sub>), which contributes to fuel loss. The fine grains increase grain boundary density, extending H₂ diffusion paths, while LAGBs help mitigate harmful H₂ accumulation. However, at 2300 °C, W diffuses into Y<sub>2</sub>O<sub>3</sub>, causing the Y<sub>2</sub>O<sub>3</sub> grains to grow and leading to the formation of pores and cracks. This weakens the Zener pinning effect, promoting abnormal grain growth of W, which ultimately results in an increase in high-angle grain boundaries (HAGBs) and accelerates the diffusion of H<sub>2</sub>. The study identifies three stages of W diffusion into Y<sub>2</sub>O<sub>3</sub>: initial enrichment at Y<sub>2</sub>O<sub>3</sub> grain boundaries, formation of W-depleted/W-enriched island-like structures within Y<sub>2</sub>O<sub>3</sub> grains, and the formation of a Y<sub>6</sub>WO<sub>12</sub> core-Y<sub>2</sub>O<sub>3</sub> shell structure at 2300 °C, providing valuable insights for optimizing Y<sub>2</sub>O<sub>3</sub> composites for NTP applications.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"137 ","pages":"Article 107649"},"PeriodicalIF":4.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894179","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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