Pub Date : 2024-12-14DOI: 10.1016/j.ijrmhm.2024.107020
S.G. Huang, C. Liu, B.L. Liu, Z. Anwer, J. Vleugels
The multi-component phase diagrams, microstructure and correlated mechanical properties of recently developed NbC-Ni based cermets are described, allowing to elucidate the correlations between composition, microstructure and mechanical properties, and address some potential applications. The influence of the carbon content, binder content, and secondary carbide additions on the microstructure and mechanical properties of NbC-based cermets are presented in detail. The reported materials focus on NbC-Ni matrix grades with 6–20 wt% Ni binder and 4–20 wt% (VC, Mo2C, WC, TiC, and/or Ti(CxNy)) additions densified by liquid phase sintering in vacuum. The results revealed that the NbC grain growth was significantly limited by some combinations of carbide or carbonitride additions, strongly influencing the mechanical properties. The NbC-based cermets offer mechanical properties that would allow them to partially replace WC-Co and Ti(C,N)-Ni in some specific wear resistant applications.
{"title":"NbC-Ni based cermets: Phase diagrams, microstructure and mechanical properties","authors":"S.G. Huang, C. Liu, B.L. Liu, Z. Anwer, J. Vleugels","doi":"10.1016/j.ijrmhm.2024.107020","DOIUrl":"https://doi.org/10.1016/j.ijrmhm.2024.107020","url":null,"abstract":"The multi-component phase diagrams, microstructure and correlated mechanical properties of recently developed NbC-Ni based cermets are described, allowing to elucidate the correlations between composition, microstructure and mechanical properties, and address some potential applications. The influence of the carbon content, binder content, and secondary carbide additions on the microstructure and mechanical properties of NbC-based cermets are presented in detail. The reported materials focus on NbC-Ni matrix grades with 6–20 wt% Ni binder and 4–20 wt% (VC, Mo<ce:inf loc=\"post\">2</ce:inf>C, WC, TiC, and/or Ti(C<ce:inf loc=\"post\">x</ce:inf>N<ce:inf loc=\"post\">y</ce:inf>)) additions densified by liquid phase sintering in vacuum. The results revealed that the NbC grain growth was significantly limited by some combinations of carbide or carbonitride additions, strongly influencing the mechanical properties. The NbC-based cermets offer mechanical properties that would allow them to partially replace WC-Co and Ti(C,N)-Ni in some specific wear resistant applications.","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"36 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825384","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 : 2024-11-28DOI: 10.1016/j.ijrmhm.2024.106984
A. Bjerke , J. Casas , F. Lenrick , J.M. Andersson , R. M'Saoubi , V. Bushlya
Polycrystalline cubic boron nitride (pcBN) is a very promising tool material for turning martensitic stainless steels at high cutting speeds (vc > 200 m/min). The competitive advantage of pcBN over cemented carbide increases as the cutting speed is increased. Changing the speed might lead to a shift in the wear balance and hence the knowledge about tool wear below vc = 200 m/min might not be applicable at vc = 600 m/min. The coatings designed for the lower speed range might also not be performing in the same way at higher speeds. This paper investigates the wear mechanism of uncoated and (Ti,Al)N coated pcBN tools when turning 17–4 PH in a hardened condition at speeds vc = 200–600 m/min. Both scanning and transmission electron microscopy are used to study the worn tools. The in-depth analysis reveals that adhesive wear is only active at low speeds. Increasing the speed does however lead to more wear by diffusion and oxidation. The cBN is preferentially worn out, leaving the TiC binder at the tool-chip interface. Oxidation results in the accelerated wear of the pcBN but also in the formation of metal oxides within the adhered build up layer. The (Ti,Al)N coating does not significantly extend the tool life within this speed range, but it suppresses the adhesive wear mechanism preventing premature tool failure.
{"title":"On the wear mechanisms of uncoated and coated pcBN tools during turning of 17–4 PH martensitic stainless steel","authors":"A. Bjerke , J. Casas , F. Lenrick , J.M. Andersson , R. M'Saoubi , V. Bushlya","doi":"10.1016/j.ijrmhm.2024.106984","DOIUrl":"10.1016/j.ijrmhm.2024.106984","url":null,"abstract":"<div><div>Polycrystalline cubic boron nitride (pcBN) is a very promising tool material for turning martensitic stainless steels at high cutting speeds (<em>v</em><sub><em>c</em></sub> > 200 m/min). The competitive advantage of pcBN over cemented carbide increases as the cutting speed is increased. Changing the speed might lead to a shift in the wear balance and hence the knowledge about tool wear below <em>v</em><sub><em>c</em></sub> = 200 m/min might not be applicable at <em>v</em><sub><em>c</em></sub> = 600 m/min. The coatings designed for the lower speed range might also not be performing in the same way at higher speeds. This paper investigates the wear mechanism of uncoated and (Ti,Al)N coated pcBN tools when turning 17–4 PH in a hardened condition at speeds <em>v</em><sub><em>c</em></sub> = 200–600 m/min. Both scanning and transmission electron microscopy are used to study the worn tools. The in-depth analysis reveals that adhesive wear is only active at low speeds. Increasing the speed does however lead to more wear by diffusion and oxidation. The cBN is preferentially worn out, leaving the TiC binder at the tool-chip interface. Oxidation results in the accelerated wear of the pcBN but also in the formation of metal oxides within the adhered build up layer. The (Ti,Al)N coating does not significantly extend the tool life within this speed range, but it suppresses the adhesive wear mechanism preventing premature tool failure.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"127 ","pages":"Article 106984"},"PeriodicalIF":4.2,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Refractory metal carbides, usually fabricated via solid state reactions, require precise control of their reactants and temperature, especially when they enter a complex compositional space, like high-entropy (multi-component) carbides. In this work, the solid-state reactions of tungsten based refractory metal carbides M-W-C (M = Ti, Zr, Hf, V, Nb, Ta) are systematically studied through first-principles thermodynamic calculations and percolation simulations, and its relationship with symmetric principles is unraveled. Symmetric hierarchy is defined by the group-subgroup Bärnighausen tree and the gap in their space group number. It suggests MC and WC/W2C are two possible reactants to form the highest symmetric M-W-C ternary carbides, and indicates the larger the gap in their space group number, the harder the reactions. From the symmetric hierarchy, we found the reaction path from MC to M-W-C ternary carbides is the most probable, supported by the Gibbs reaction free energy. Carbon percolation within the metal framework plays another role in the solid-state reactions of tungsten based refractory metal carbides. It reveals the phase transition from M6W6C to M3W3C undergoes a transient M2W2C. The success in predicting the phase relationship of M-W-C ternary system offers a new paradigm for the design and synthesis of high-entropy carbides, nitrides, and oxides.
{"title":"Unraveling symmetric hierarchy in solid-state reactions of tungsten-based refractory metal carbides through first-principles calculations","authors":"Juan Ding, Wentan Zhu, Yunzhu Ma, Wensheng Liu, Qingshan Cai, Chaoping Liang","doi":"10.1016/j.ijrmhm.2024.106977","DOIUrl":"10.1016/j.ijrmhm.2024.106977","url":null,"abstract":"<div><div>Refractory metal carbides, usually fabricated via solid state reactions, require precise control of their reactants and temperature, especially when they enter a complex compositional space, like high-entropy (multi-component) carbides. In this work, the solid-state reactions of tungsten based refractory metal carbides M-W-C (M = Ti, Zr, Hf, V, Nb, Ta) are systematically studied through first-principles thermodynamic calculations and percolation simulations, and its relationship with symmetric principles is unraveled. Symmetric hierarchy is defined by the group-subgroup Bärnighausen tree and the gap in their space group number. It suggests MC and WC/W<sub>2</sub>C are two possible reactants to form the highest symmetric M-W-C ternary carbides, and indicates the larger the gap in their space group number, the harder the reactions. From the symmetric hierarchy, we found the reaction path from MC to M-W-C ternary carbides is the most probable, supported by the Gibbs reaction free energy. Carbon percolation within the metal framework plays another role in the solid-state reactions of tungsten based refractory metal carbides. It reveals the phase transition from M<sub>6</sub>W<sub>6</sub>C to M<sub>3</sub>W<sub>3</sub>C undergoes a transient M<sub>2</sub>W<sub>2</sub>C. The success in predicting the phase relationship of M-W-C ternary system offers a new paradigm for the design and synthesis of high-entropy carbides, nitrides, and oxides.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"127 ","pages":"Article 106977"},"PeriodicalIF":4.2,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747438","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 : 2024-11-26DOI: 10.1016/j.ijrmhm.2024.106978
B.Z. Sun , L. Gao , L.H. Lou , R. Li , J.P. Song , Y.L. Liu , Y. Qi
The materials, primarily utilized in the manufacturing process, significantly impact the microstructure and mechanical properties of W-HfC alloys. In this study, different initial composition, such as HfH2/WC, HfH2/C and HfC, were respectively mixed into W powders, three categories of W-HfC alloys (abbreviated as WHC1, WHC2 and WHC3 successively) were fabricated by in-situ reaction sintering methods. The microstructure and mechanical properties of three alloys were investigated comparatively by using X-ray diffraction, electron microscopy and high temperature tensile tests. The results revealed that WHC2 alloy presents an exceptional ductile-brittle transition temperature of ∼300 °C and the best comprehensive performance. Tensile testing at 300 °C indicates that WHC2 alloy exhibits a complete plastic fracture curve with a tensile strength of 400 MPa and a residual deformation of 9 %, as well as the plasticity enhancement. It is mainly attributable to the dispersion strengthening effect of second phase particles at grain boundaries and within W-matrix grains. Furthermore, the excellent overall performance of the WHC2 alloy demonstrates that the in-situ reaction can significantly reduce sintering difficulties, while the resultant second phase particles provide considerable advantages in improving the properties of W-based alloys. These findings provide valuable insights into the synthesis process and mechanical performance of W-HfC alloys, enabling advancements in their application in high-temperature environments.
制造过程中主要使用的材料会对 W-HfC 合金的微观结构和机械性能产生重大影响。本研究将不同的初始成分（如 HfH2/WC、HfH2/C 和 HfC）分别混合到 W 粉末中，采用原位反应烧结法制备了三类 W-HfC 合金（分别简称为 WHC1、WHC2 和 WHC3）。通过 X 射线衍射、电子显微镜和高温拉伸试验对三种合金的微观结构和机械性能进行了比较研究。结果表明，WHC2 合金的韧性-脆性转变温度为 300 ℃，综合性能最佳。300 ℃拉伸试验表明，WHC2 合金呈现出完整的塑性断裂曲线，抗拉强度为 400 MPa，残余变形为 9%，塑性增强。这主要归因于第二相颗粒在晶界和 W 基体晶粒内的分散强化效应。此外，WHC2 合金优异的综合性能表明，原位反应可显著降低烧结难度，而由此产生的第二相颗粒在改善 W 基合金性能方面具有相当大的优势。这些发现为 W-HfC 合金的合成过程和机械性能提供了宝贵的见解，从而推动了它们在高温环境中的应用。
{"title":"Microstructure and mechanical properties of W-HfC alloy synthesized by in-situ fabrication via pressureless sintering","authors":"B.Z. Sun , L. Gao , L.H. Lou , R. Li , J.P. Song , Y.L. Liu , Y. Qi","doi":"10.1016/j.ijrmhm.2024.106978","DOIUrl":"10.1016/j.ijrmhm.2024.106978","url":null,"abstract":"<div><div>The materials, primarily utilized in the manufacturing process, significantly impact the microstructure and mechanical properties of W-HfC alloys. In this study, different initial composition, such as HfH<sub>2</sub>/WC, HfH<sub>2</sub>/C and HfC, were respectively mixed into W powders, three categories of W-HfC alloys (abbreviated as WHC1, WHC2 and WHC3 successively) were fabricated by in-situ reaction sintering methods. The microstructure and mechanical properties of three alloys were investigated comparatively by using X-ray diffraction, electron microscopy and high temperature tensile tests. The results revealed that WHC2 alloy presents an exceptional ductile-brittle transition temperature of ∼300 °C and the best comprehensive performance. Tensile testing at 300 °C indicates that WHC2 alloy exhibits a complete plastic fracture curve with a tensile strength of 400 MPa and a residual deformation of 9 %, as well as the plasticity enhancement. It is mainly attributable to the dispersion strengthening effect of second phase particles at grain boundaries and within W-matrix grains. Furthermore, the excellent overall performance of the WHC2 alloy demonstrates that the in-situ reaction can significantly reduce sintering difficulties, while the resultant second phase particles provide considerable advantages in improving the properties of W-based alloys. These findings provide valuable insights into the synthesis process and mechanical performance of W-HfC alloys, enabling advancements in their application in high-temperature environments.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"127 ","pages":"Article 106978"},"PeriodicalIF":4.2,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719667","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 : 2024-11-26DOI: 10.1016/j.ijrmhm.2024.106975
Zhongyou Que , Xingyu Li , Lin Zhang , En Mei , Chenguang Guo , Haishen Sun , Junming Liu , Mingli Qin , Gang Chen , Xuanhui Qu
Tungsten‑rhenium (W-Re) alloys are extensively used in medical devices, electronics, industrial equipment, aerospace, and nuclear energy sectors due to their low ductile-to-brittle transition temperature (DBTT), excellent high-temperature creep resistance, and superior properties related to recrystallization, ablation, and irradiation at elevated temperatures. However, with the advancement of technologies in these critical fields, the performance demands on W-Re alloys are continually increasing. As a result, optimizing the fabrication processes of W-Re alloys to enhance their performance under ultra-high temperature conditions has become essential. This review provides a detailed overview of the ultra-high temperature applications of W-Re alloys, the effects of Re alloying on their performance, various strengthening methods and mechanisms, and fabrication techniques. By analyzing the strengthening mechanisms, we identify that advancements in powder preparation, bulk densification, and deformation processing are key to improving the stable performance of W-Re alloys under extreme temperatures. Additionally, we address several challenges related to the fabrication methods and propose solutions. We hope that this comprehensive review will support researchers in developing W-Re alloys with enhanced performance while addressing the production and engineering challenges involved.
{"title":"Preparation and properties of tungsten-rhenium alloys resistant to ultra-high temperatures","authors":"Zhongyou Que , Xingyu Li , Lin Zhang , En Mei , Chenguang Guo , Haishen Sun , Junming Liu , Mingli Qin , Gang Chen , Xuanhui Qu","doi":"10.1016/j.ijrmhm.2024.106975","DOIUrl":"10.1016/j.ijrmhm.2024.106975","url":null,"abstract":"<div><div>Tungsten‑rhenium (W-Re) alloys are extensively used in medical devices, electronics, industrial equipment, aerospace, and nuclear energy sectors due to their low ductile-to-brittle transition temperature (DBTT), excellent high-temperature creep resistance, and superior properties related to recrystallization, ablation, and irradiation at elevated temperatures. However, with the advancement of technologies in these critical fields, the performance demands on W-Re alloys are continually increasing. As a result, optimizing the fabrication processes of W-Re alloys to enhance their performance under ultra-high temperature conditions has become essential. This review provides a detailed overview of the ultra-high temperature applications of W-Re alloys, the effects of Re alloying on their performance, various strengthening methods and mechanisms, and fabrication techniques. By analyzing the strengthening mechanisms, we identify that advancements in powder preparation, bulk densification, and deformation processing are key to improving the stable performance of W-Re alloys under extreme temperatures. Additionally, we address several challenges related to the fabrication methods and propose solutions. We hope that this comprehensive review will support researchers in developing W-Re alloys with enhanced performance while addressing the production and engineering challenges involved.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"127 ","pages":"Article 106975"},"PeriodicalIF":4.2,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759723","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 : 2024-11-26DOI: 10.1016/j.ijrmhm.2024.106976
Jinchi Huang , Qinghong Zhong , Ziqi Cao , Yifan Ding , Zhehui Zhou , Yan Ma , Guang Ran
The microstructural evolution of irradiation-induced point defects around the precipitates during in-situ 30 keV He+ irradiation was systematically investigated in Mo3Nb alloy using transmission electron microscopy (TEM) at various temperatures: room temperature (RT), 573 K, and 1073 K. The average size and volume number density of dislocation loops were obtain under the influence of irradiation temperature, fluence and different types (sizes and shapes) of precipitates. The irradiated defects showed distinct characteristics that correlated with the precipitate types. Dislocation loops of larger size and lower density were observed around the larger precipitates, which were also influenced by the precipitate morphology. Temperature had a great effect on defect migration, resulting in a decrease in loop density and an increase in loop size. Furthermore, the hardening effect attributed to irradiation-induced loops decreased with the increase of temperature and precipitate size. The dissolution of precipitates became increasingly pronounced with the increase of temperature, and irradiation could accelerate the process. At 573 K, the dissolution was only found in the large non-spherical precipitate, while at 1073 K, all the precipitates underwent dissolution. The annealing experiment conducted at 1073 K showed that the dissolution of large-sized precipitates would lead to the dispersion of small-sized precipitates, which was beneficial to increase the interfaces and potentially improve the radiation tolerance and mechanical properties of the alloy.
{"title":"Evolution of precipitate and its effect on dislocation loops during in-situ He+ irradiation and annealing","authors":"Jinchi Huang , Qinghong Zhong , Ziqi Cao , Yifan Ding , Zhehui Zhou , Yan Ma , Guang Ran","doi":"10.1016/j.ijrmhm.2024.106976","DOIUrl":"10.1016/j.ijrmhm.2024.106976","url":null,"abstract":"<div><div>The microstructural evolution of irradiation-induced point defects around the precipitates during in-situ 30 keV He<sup>+</sup> irradiation was systematically investigated in Mo<img>3Nb alloy using transmission electron microscopy (TEM) at various temperatures: room temperature (RT), 573 K, and 1073 K. The average size and volume number density of dislocation loops were obtain under the influence of irradiation temperature, fluence and different types (sizes and shapes) of precipitates. The irradiated defects showed distinct characteristics that correlated with the precipitate types. Dislocation loops of larger size and lower density were observed around the larger precipitates, which were also influenced by the precipitate morphology. Temperature had a great effect on defect migration, resulting in a decrease in loop density and an increase in loop size. Furthermore, the hardening effect attributed to irradiation-induced loops decreased with the increase of temperature and precipitate size. The dissolution of precipitates became increasingly pronounced with the increase of temperature, and irradiation could accelerate the process. At 573 K, the dissolution was only found in the large non-spherical precipitate, while at 1073 K, all the precipitates underwent dissolution. The annealing experiment conducted at 1073 K showed that the dissolution of large-sized precipitates would lead to the dispersion of small-sized precipitates, which was beneficial to increase the interfaces and potentially improve the radiation tolerance and mechanical properties of the alloy.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"127 ","pages":"Article 106976"},"PeriodicalIF":4.2,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747439","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}
A novel tungsten heavy alloy (WHA), with composition 89 W-5.1Ni-3.4Cu-1.5Fe-1La₂O₃ (wt%) (Modified WHA) and the Ni/Cu ratio of 6/4, was sintered at 1400 °C for 1 h. The synergetic effects of La2O3 dispersion strengthening, which controls W particle growth, and Fe solid solution strengthening within the matrix, enhancing the compressive and bending strength of modified WHA. Microstructural analysis showed tungsten particle size and contiguity of 21 μm and 0.41, while mechanical testing revealed substantial improvements, with a hardness of 343 HV5, compressive strength of 2250 MPa, and bending strength of 1417 MPa. Fractography indicated failure modes involving WW and W-matrix de-cohesion, transgranular fractures, and dimpled fractures, attributed to the combined strengthening mechanisms. Transmission electron microscopy (TEM) analysis provided detailed insights into the sintered alloys, particularly revealing the locations of La2O3, WW, and W-matrix interfaces, as well as the distribution of precipitates within the matrix and tungsten. This study demonstrates that the tailored addition of La2O3 and Fe significantly enhances WHA properties, positioning this alloy as a robust candidate for high-strength applications.
{"title":"Microstructure and mechanical characterizations of liquid phase sintered W-Ni-Cu heavy alloy modified with La2O3 and Fe addition","authors":"Navindra Shekhar Shakunt, Gouthama, Anish Upadhyaya","doi":"10.1016/j.ijrmhm.2024.106981","DOIUrl":"10.1016/j.ijrmhm.2024.106981","url":null,"abstract":"<div><div>A novel tungsten heavy alloy (WHA), with composition 89 W-5.1Ni-3.4Cu-1.5Fe-1La₂O₃ (wt%) (Modified WHA) and the Ni/Cu ratio of 6/4, was sintered at 1400 °C for 1 h. The synergetic effects of La<sub>2</sub>O<sub>3</sub> dispersion strengthening, which controls W particle growth, and Fe solid solution strengthening within the matrix, enhancing the compressive and bending strength of modified WHA. Microstructural analysis showed tungsten particle size and contiguity of 21 μm and 0.41, while mechanical testing revealed substantial improvements, with a hardness of 343 HV<sub>5</sub>, compressive strength of 2250 MPa, and bending strength of 1417 MPa. Fractography indicated failure modes involving W<img>W and W-matrix de-cohesion, transgranular fractures, and dimpled fractures, attributed to the combined strengthening mechanisms. Transmission electron microscopy (TEM) analysis provided detailed insights into the sintered alloys, particularly revealing the locations of La<sub>2</sub>O<sub>3</sub>, W<img>W, and W-matrix interfaces, as well as the distribution of precipitates within the matrix and tungsten. This study demonstrates that the tailored addition of La<sub>2</sub>O<sub>3</sub> and Fe significantly enhances WHA properties, positioning this alloy as a robust candidate for high-strength applications.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"127 ","pages":"Article 106981"},"PeriodicalIF":4.2,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747437","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 : 2024-11-23DOI: 10.1016/j.ijrmhm.2024.106973
Heming Zhang , Defa Wu , Jianyu Fu , Jize Jiang , Yinshui Liu
Suspended silt particles in natural water inevitably enter open water hydraulic systems, challenging the tribological performance of materials and complicating the selection of appropriate system filtration precision. This study aims to investigate the tribological performance of textured surfaces and the mechanisms of particle contamination resistance under different filtration precisions. Purified water was used as a control, while silt water with an initial mass concentration of 1 % was filtered through 100 μm, 40 μm, and 10 μm filters as experimental groups. The friction and wear performance of HVOF-sprayed WC-9Co-5Cr-1Ni coatings, both textured and untextured, paired with untextured Si3N4, was evaluated under these lubrication conditions. Results showed that texturing reduced the friction coefficients significantly. In silt-laden environments, textures not only stored particles but also facilitated their fragmentation or layered delamination through interactions with texture edges. Compared to untextured surfaces, textured surfaces reduced the filtration precision requirement from 10 μm to 40 μm without significant material damage and facilitated lubricating film formation in silt-laden environments. These findings may provide guidance for texture design in tribopairs and filtration strategies in silt-contaminated hydraulic systems.
{"title":"Tribological performance of textured WC coatings under silt-laden water with different filtration precisions","authors":"Heming Zhang , Defa Wu , Jianyu Fu , Jize Jiang , Yinshui Liu","doi":"10.1016/j.ijrmhm.2024.106973","DOIUrl":"10.1016/j.ijrmhm.2024.106973","url":null,"abstract":"<div><div>Suspended silt particles in natural water inevitably enter open water hydraulic systems, challenging the tribological performance of materials and complicating the selection of appropriate system filtration precision. This study aims to investigate the tribological performance of textured surfaces and the mechanisms of particle contamination resistance under different filtration precisions. Purified water was used as a control, while silt water with an initial mass concentration of 1 % was filtered through 100 μm, 40 μm, and 10 μm filters as experimental groups. The friction and wear performance of HVOF-sprayed WC-9Co-5Cr-1Ni coatings, both textured and untextured, paired with untextured Si<sub>3</sub>N<sub>4</sub>, was evaluated under these lubrication conditions. Results showed that texturing reduced the friction coefficients significantly. In silt-laden environments, textures not only stored particles but also facilitated their fragmentation or layered delamination through interactions with texture edges. Compared to untextured surfaces, textured surfaces reduced the filtration precision requirement from 10 μm to 40 μm without significant material damage and facilitated lubricating film formation in silt-laden environments. These findings may provide guidance for texture design in tribopairs and filtration strategies in silt-contaminated hydraulic systems.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"127 ","pages":"Article 106973"},"PeriodicalIF":4.2,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719666","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}
The present study investigates the influence of adding micro/nanoparticles of Al2O3 (0.5–1.5 wt%) on the microstructure, electrochemical behavior, and thermal stability of a W-Ni-Fe matrix sintered by the spark plasma process. Corrosion characteristics were assessed through Tafel polarization and electrochemical impedance spectroscopy techniques in a 0.1 M HCl solution. The extent of corrosion was evaluated by examining the specimen surfaces before and after the corrosion test using field emission scanning electron microscopy and x-ray diffraction methods. Additionally, thermo-gravimetric analysis was employed to investigate the weight loss behavior and thermal stability of the composites up to 1000 °C in dry air atmosphere. The nanoparticles of Al2O3 significantly enhanced the corrosion resistance of the W–4.9Ni–2.1Fe matrix, with up to 90 % improvement observed in the presence of 1 wt% nanoparticles in the HCl solution. The uniform dispersion of nanoparticles throughout the matrix caused a decrease in the grain size and the cathodic area. Furthermore, the nanocomposites exhibited superior thermal behavior and minimal weight changes, as indicated by the thermoanalytical results. The thermal stability of the composites was assessed, and it was found that the specimen incorporating 1 wt% nanoparticles exhibited the greatest thermal stability, characterized by a 6 % enhancement in thermal resistance.
{"title":"A new study on the electrochemical behavior and thermal stability of W–4.9Ni–2.1Fe–xAl2O3 composites","authors":"Mostafa Hasanabadi, Mahboobeh Azadi, Mardali Yousefpour","doi":"10.1016/j.ijrmhm.2024.106972","DOIUrl":"10.1016/j.ijrmhm.2024.106972","url":null,"abstract":"<div><div>The present study investigates the influence of adding micro/nanoparticles of Al<sub>2</sub>O<sub>3</sub> (0.5–1.5 wt%) on the microstructure, electrochemical behavior, and thermal stability of a W-Ni-Fe matrix sintered by the spark plasma process. Corrosion characteristics were assessed through Tafel polarization and electrochemical impedance spectroscopy techniques in a 0.1 M HCl solution. The extent of corrosion was evaluated by examining the specimen surfaces before and after the corrosion test using field emission scanning electron microscopy and x-ray diffraction methods. Additionally, thermo-gravimetric analysis was employed to investigate the weight loss behavior and thermal stability of the composites up to 1000 °C in dry air atmosphere. The nanoparticles of Al<sub>2</sub>O<sub>3</sub> significantly enhanced the corrosion resistance of the W–4.9Ni–2.1Fe matrix, with up to 90 % improvement observed in the presence of 1 wt% nanoparticles in the HCl solution. The uniform dispersion of nanoparticles throughout the matrix caused a decrease in the grain size and the cathodic area. Furthermore, the nanocomposites exhibited superior thermal behavior and minimal weight changes, as indicated by the thermoanalytical results. The thermal stability of the composites was assessed, and it was found that the specimen incorporating 1 wt% nanoparticles exhibited the greatest thermal stability, characterized by a 6 % enhancement in thermal resistance.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"127 ","pages":"Article 106972"},"PeriodicalIF":4.2,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719669","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}
The present study investigates the high temperature erosion behavior of HVOF sprayed composite coatings on T11 steel substrates by studying (Cr₃C₂-NiCr)Si and WC-Co/NiCrAlY coatings. Phase composition, cross sectional microstructure, mechanical properties, and erosion resistance were analyzed by XRD, EDS, SEM and three-dimensional optical profilography. The results demonstrate that the WC-Co/NiCrAlY coating has higher erosion resistance and oxidation stability for all temperatures and impact angles tested. Its enhanced performance in high temperature and erosive conditions is attributable to the formation of stable protective oxides such as Al₂O₃ and Cr₂O₃ and intermetallic phases such as Ni₃Al and Cr₃C₂. The NiCrAlY matrix prevents significant decarburization of WC particles, and hence phase stability and oxidation resistance. The (Cr₃C₂-NiCr)Si coating has higher microhardness due to silicide phases, but is more vulnerable to direct impacts and inferior oxidation resistance. The phase transformations for both coatings are favorable at elevated temperatures which enhances erosion resistance. The WC-Co/NiCrAlY coating is smooth and shallower in erosion craters and is perfectly suited for harsh environments demanding high toughness, impact resistance and oxidation stability. For applications in which high hardness is needed in less severe conditions, the (Cr₃C₂-NiCr)Si coating is more suitable.
{"title":"Studies on high temperature erosion behavior of HVOF-sprayed (Cr₃C₂-NiCr)Si and WC-Co/NiCrAlY composite coatings","authors":"Subbarao Medabalimi , Ajit M. Hebbale , Suresh Gudala , Uzwalkiran Rokkala , M.R. Ramesh","doi":"10.1016/j.ijrmhm.2024.106970","DOIUrl":"10.1016/j.ijrmhm.2024.106970","url":null,"abstract":"<div><div>The present study investigates the high temperature erosion behavior of HVOF sprayed composite coatings on T11 steel substrates by studying (Cr₃C₂-NiCr)Si and WC-Co/NiCrAlY coatings. Phase composition, cross sectional microstructure, mechanical properties, and erosion resistance were analyzed by XRD, EDS, SEM and three-dimensional optical profilography. The results demonstrate that the WC-Co/NiCrAlY coating has higher erosion resistance and oxidation stability for all temperatures and impact angles tested. Its enhanced performance in high temperature and erosive conditions is attributable to the formation of stable protective oxides such as Al₂O₃ and Cr₂O₃ and intermetallic phases such as Ni₃Al and Cr₃C₂. The NiCrAlY matrix prevents significant decarburization of WC particles, and hence phase stability and oxidation resistance. The (Cr₃C₂-NiCr)Si coating has higher microhardness due to silicide phases, but is more vulnerable to direct impacts and inferior oxidation resistance. The phase transformations for both coatings are favorable at elevated temperatures which enhances erosion resistance. The WC-Co/NiCrAlY coating is smooth and shallower in erosion craters and is perfectly suited for harsh environments demanding high toughness, impact resistance and oxidation stability. For applications in which high hardness is needed in less severe conditions, the (Cr₃C₂-NiCr)Si coating is more suitable.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"127 ","pages":"Article 106970"},"PeriodicalIF":4.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700877","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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