International Journal of Refractory Metals & Hard Materials最新文献

{"title":"Sintering polycrystalline silicon carbide composite ceramics with ultra-high hardness under high pressure","authors":"Peihong He,&nbsp;Yulei He,&nbsp;Wenjia Liang,&nbsp;Haidong Long,&nbsp;Ling Ran,&nbsp;Peng Yang,&nbsp;Fang Peng","doi":"10.1016/j.ijrmhm.2024.106918","DOIUrl":"10.1016/j.ijrmhm.2024.106918","url":null,"abstract":"<div><div>Silicon carbide (SiC) is an important structural ceramic material, exhibiting exceptional comprehensive properties that are unmatched by metals and other structural materials. In this study, a combination of α-SiC micron powder and β-SiC nanopowder was utilized as precursor materials for high pressure and high temperature (HPHT) sintering. Under a pressure of 5.0 GPa, polycrystalline SiC samples with mixed grain size were sintered within a temperature range from 1000 to 1700 °C, and compared with SiC samples sintered from single micron powder under identical temperature and pressure conditions. The microstructures of the two sets of SiC samples were observed using scanning electron microscopy. Additionally, the stress states and strengthening mechanisms among SiC grains with mixed grain size under HPHT were further analyzed in conjunction with X-ray diffraction results. The polycrystalline SiC composite ceramics sintered at 1700 °C exhibited superior mechanical and thermal properties, achieving a Vickers hardness of 35.2 GPa that is 23.5 % higher than that obtained by conventional spark plasma sintering and even surpassing the hardness of single crystal SiC, demonstrating thermal stability up to 1405 °C in air environment. Transmission electron microscopy was employed to analyze defects and plastic deformation in these samples. The study suggests that the primary strengthening mechanisms of the sintered polycrystalline SiC composite ceramics under HPHT include the increase in micro defects induced by in-situ plastic deformation at elevated temperatures and the effects of high-temperature creep. This study provides new insights into the HPHT sintering of hard materials.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106918"},"PeriodicalIF":4.2,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142438470","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}

{"title":"Microstructural characteristics and mechanical properties of laser-welded Ta10W/GH3030 joints with beam offset","authors":"Jiaxuan Zhao ,&nbsp;Jie Ning ,&nbsp;Linjie Zhang ,&nbsp;Gang Zhao ,&nbsp;Shurong Li ,&nbsp;Won-Ik Cho","doi":"10.1016/j.ijrmhm.2024.106919","DOIUrl":"10.1016/j.ijrmhm.2024.106919","url":null,"abstract":"<div><div>Influences of the laser beam offset (LBO) on the microstructures as well as room-temperature and high-temperature mechanical properties of Ta10W/GH3030 dissimilar-material joints were investigated. In laser-welded Ta10W/GH3030 joints prepared under three conditions with LBOs of −0.2 mm (offset toward Ta10W), 0 mm, and + 0.2 mm (offset toward GH3030): the fusion zones (FZ) all contained expulsed substances Ni₃Ta, NiTa, and Cr₂Ta and their microhardness was certainly higher than the base metal (BM); a transition layer containing high contents of Ni₃Ta, NiTa, and Cr₂Ta phases was observed at the Ta10W/FZ interface. With the increase of the LBO, the contents of Ni₃Ta, NiTa, and Cr₂Ta in the FZ gradually declined, the average grain size in the FZ increased slightly, the microhardness of the FZ dropped rapidly, and the thickness of the transition layer at the Ta10W/FZ interface reduced obviously. Either in the room-temperature or high-temperature (750 °C) tensile tests, Ta10W/GH3030 joints were always fractured at the Ta10W/FZ interface, showing the typical brittle fracture mode, and the tensile strength of joints was enhanced with the increasing LBO. Under LBOs of −0.2, 0, and + 0.2 mm, the room-temperature tensile strengths of Ta10W/GH3030 dissimilar-material joints were 266.4, 308.6, and 341.2 MPa, while the high-temperature (750 °C) tensile strengths were 97.6, 191.5, and 202.7 MPa, respectively.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106919"},"PeriodicalIF":4.2,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444956","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}

{"title":"Contact fatigue property of diamond-like carbon films with different structure in cyclic impact conditions","authors":"Mingxiu Chong ,&nbsp;Zhongrong Geng ,&nbsp;Guangan Zhang ,&nbsp;Xia Li ,&nbsp;Xueqian Cao","doi":"10.1016/j.ijrmhm.2024.106921","DOIUrl":"10.1016/j.ijrmhm.2024.106921","url":null,"abstract":"<div><div>Repeated contact with high loads can cause damage to the surface of the DLC films and thus affect their fatigue strength. This study systematically investigates the contact fatigue damage of the DLC films with different carbon structures (a-C, a-C:H, and ta-C) by macro-scale cyclic impact tests with alternating loads. The results reveal that the a-C film possesses significantly superior contact fatigue property compared to the a-C:H and ta-C films under high load. The graphitization transformation of the a-C and a-C:H films lead to a decrease in hardness and elastic modulus. The work-hardening of the ta-C films results in an increase in hardness and elastic modulus. The findings indicate that under cyclic load impact conditions, films need a combination of load support and fatigue resistance to achieve optimum lifetime, and solely increasing film hardness could be accompanied by brittle fracture and higher wear.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106921"},"PeriodicalIF":4.2,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444957","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}

{"title":"TiB2-Fe hard alloys obtained using SHS powders of the Ti-B-Fe system","authors":"O.K. Lepakova,&nbsp;O.A. Shkoda","doi":"10.1016/j.ijrmhm.2024.106915","DOIUrl":"10.1016/j.ijrmhm.2024.106915","url":null,"abstract":"<div><div>A method for producing TiB₂-Fe composite powder with high performance characteristics has been developed. Optimal modes of self-propagating high-temperature synthesis, grinding of synthesis products and subsequent sintering have been found. The best properties are exhibited by samples sintered from composite powder of the composition TiB₂: Fe = 52:48 (wt%) at a sintering temperature of 1400 °C for 60 min. They have a density of 98.2 %, an HRA index of 90 and σ _bend = 1200 MPa. The temperature characteristics of synthesis and microstructure of the products have been studied. Mechanical tests of the obtained materials have been carried out and the possibility of its application in the woodworking industry has been shown.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106915"},"PeriodicalIF":4.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433343","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}

{"title":"Fracture toughness of cemented carbides and its correlations with other material properties","authors":"Vitaliy Kazymyrovych","doi":"10.1016/j.ijrmhm.2024.106916","DOIUrl":"10.1016/j.ijrmhm.2024.106916","url":null,"abstract":"<div><div>For cemented carbides, also known as hardmetals, fracture toughness has always been viewed as one of the key properties, which resulted in large amount of research in the subject. This study presents fracture toughness results for 30 cemented carbide grades, covering wide range of microstructures and associated properties. Toughness data was generated at room temperature by three-point bend testing of chevron notched samples. In addition to relatively well studied influences of cobalt content and carbides grain size on fracture toughness, current research also examines impacts of cubic carbides content and alloying elements on material toughness. In this work, traditional “hardness - toughness” diagram is complemented by “coercivity - toughness”, which is shown to be more appropriate for illustration of the detrimental effect that cubic carbides have on fracture toughness. The results presented here also indicate that alloying of binder with Cr or Ru does not have any noticeable effect on room temperature toughness and presence of eta-phase in the microstructure is not necessarily harmful for toughness. In addition, this research illustrates a correlation between fracture toughness and thermal conductivity of cemented carbides. Most importantly, by utilising broad experimental data and regression analysis, an attempt is made to formulate a set of empirical equations that would allow fracture toughness estimate from readily available or easily measurable material parameters. It is shown that fracture toughness of cemented carbides can be predicted with good accuracy from coercivity and cubic carbides content. In addition, regression equations for estimate of hardness and the average carbides grain size are proposed.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"126 ","pages":"Article 106916"},"PeriodicalIF":4.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554956","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}

{"title":"In-situ observation of recrystallization of K-doped tungsten sheets using laser reflection","authors":"Lukas Wimmer ,&nbsp;Christian Bienert ,&nbsp;Robert Schiftner ,&nbsp;Christoph Eisenmenger-Sittner","doi":"10.1016/j.ijrmhm.2024.106913","DOIUrl":"10.1016/j.ijrmhm.2024.106913","url":null,"abstract":"<div><div>The microstructure of (doped) tungsten sheets is crucial for their mechanical behavior. Within this study, a new method, based on laser reflection, is proposed to in-situ determine the process of (secondary) recrystallization and the resulting grain size of (doped) tungsten sheets under ultra high vacuum conditions. The system introduced here allows to position the reflection setup at a reasonable distance from the sample to further observe the sample temperature via a pyrometer. The main signals of interest are the reflection intensity, the resulting distribution, and changes thereof. Furthermore, the proposed method can be carried out on polished and as rolled surfaces likewise. This novel method makes it possible to determine the secondary recrystallization temperature (<span><math><msub><mi>T</mi><msub><mi>R</mi><mi>x</mi></msub></msub></math></span>) in rolled (K-)doped tungsten sheets within a single non-isothermal annealing procedure. The average surface grain size during isothermal annealing procedures can be evaluated as well. Even though the observations are generally restricted to the surface, in the case of tungsten sheets a sufficient determination of bulk recrystallization kinetics is possible as well. Furthermore, the obtained results show, that the recrystallization temperature can serve as a sufficient measure to describe the recrystallized microstructure. Even for different sample strains, <span><math><msub><mi>T</mi><msub><mi>R</mi><mi>x</mi></msub></msub></math></span> correctly predicts the average grain size resulting for various temperature increase rates. The proposed method provides a simple, coherent, and robust method to evaluate the recrystallization properties of (doped) tungsten sheets within a single measurement.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"126 ","pages":"Article 106913"},"PeriodicalIF":4.2,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656062","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}

{"title":"The influence of ball milling conditions on the powder characteristics and sintering densification of MoCu alloy","authors":"Zehang Zhuang ,&nbsp;Zongbo Li ,&nbsp;Leilei Xu ,&nbsp;Yan Feng ,&nbsp;Richu Wang ,&nbsp;Chaoqun Peng","doi":"10.1016/j.ijrmhm.2024.106914","DOIUrl":"10.1016/j.ijrmhm.2024.106914","url":null,"abstract":"<div><div>Mechanical alloying was utilized to produce Mo-30Cu(wt%) composite powder. The effects of milling conditions on the powder characteristics and sintering densification were investigated. The morphological evolution during the mechanical alloying process can be categorized into four stages: 1-individual Mo and Cu particles, 2-coexistence of Mo particles and blocky Mo<img>Cu composite particles, 3-coarse irregular composite particles, and 4-refined near-spherical composite particles or lamellar Mo<img>Cu composite particles, depending on whether process control agent (PCA) is added. The mechanical alloying degree of the Mo<img>Cu composite powder was deepened gradually from stage 1 to 4, which is influenced by the ball milling parameters. As the milling speed and milling time increase, the lattice strain and the alloying degree of the Mo<img>Cu composite powders increase while the grain size of molybdenum particles decreases, which is conducive to accelerating the sintering density. Among these ball milling parameters, an elevated milling speed notably accelerates the mechanical alloying process and the sintering density. Under the milling speed of 600 r/min, ball to powder ratio (BPR) of 10:1, and milling time of 4 h, the grain size, lattice strain, and average particle diameter of the composite powder were measured to be 48.4 nm, 0.247 %, and 21.04 μm, respectively, with the particle morphology being nearly spherical. The sintered density of the Mo<img>Cu composite reached 98.1 %, larger than the other composites.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106914"},"PeriodicalIF":4.2,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419677","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}

{"title":"Microstructure characterization and formability assessment of electron beam welded Nb-10Hf-1Ti (wt.%) refractory alloy sheets","authors":"Dibya Ranjan Behera ,&nbsp;P.S. Lin Prakash ,&nbsp;Prasun Kundu ,&nbsp;Ravi Ranjan Kumar ,&nbsp;S.V.S. Narayana Murty ,&nbsp;Sujoy Kumar Kar ,&nbsp;Sushanta Kumar Panda","doi":"10.1016/j.ijrmhm.2024.106912","DOIUrl":"10.1016/j.ijrmhm.2024.106912","url":null,"abstract":"<div><div>Formability study on welded blanks of Nb-based refractory alloy C-103 (Nb-10Hf-1Ti (wt.%)) has tremendous potential for utilizing smaller sheets for realization of large-size divergent portions of upper-stage liquid engine nozzle of satellite launch vehicles and thrusters of attitude orbital control systems. In this work, vacuum-annealed monolithic C-103 sheets were electron beam welded successfully to obtain defect-free welds and detailed microstructural and mechanical characterizations were investigated. Columnar epitaxial grains were found in fusion zone (FZ) instead of equiaxed grains in base metal (BM). Detailed SEM and HRTEM analyses revealed spherical shape of nano-sized HfO₂ precipitates with monoclinic crystal structure in the C-103 sheet. Further, microhardness across the weld cross-section indicated that the FZ had a uniform and maximum hardness of ∼195 HV_0.5 due to formation of finer nano-sized HfO₂ precipitates with higher number density, followed by a lowering of hardness in a narrow heat-affected zone. A marginal reduction in tensile strength of ∼6% with a considerable decrease in ductility of ∼29% was noticed for the welded sample. However, fracture occurred in the BM region, indicating good weld integrity. Furthermore, formability of the welded blanks was evaluated in terms of limiting dome height (LDH), forming limit diagram, and deep drawn cup depth. The effect of the presence of WZ on the formability of the C-103 sheet was estimated under uniaxial, plane strain, and biaxial tensile strain paths for the first time, and the results were compared with the monolithic sample. It was noted that the failure limit of the welded specimens decreased compared to that of the monolithic sample, resulting in a lower LDH of approximately 69% and 62% when deformed along plane strain and biaxial tensile strain paths, respectively. However, a marginal variation in LDH was observed for the uniaxial strain path. Also, the welded blank had more resistance to material flow into the die cavity due to the harder weld region, resulting in a reduction of deep drawn cup depth by 52% than that of the monolithic blank. The overall results concluded that the presence of the WZ significantly affected the formability of the C-103 sheet, especially in plane strain and biaxial strain paths. However, the fracture was never found to be propagating along the weld line, indicating the ability of the weld to sustain large plastic strains. This study provides insightful information on the formability of electron beam welded C-103 sheets for the successful fabrication of space components.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106912"},"PeriodicalIF":4.2,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527915","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}

{"title":"Corrigendum to “Tribological behavior of duplex CrN/DLC and nano-multilayer DLC-W coatings on valve tappet under elevated temperature and varying load” [International Journal of Refractory Metals and Hard Materials, 121 (2024) 106660","authors":"Funsho Olaitan Kolawole","doi":"10.1016/j.ijrmhm.2024.106911","DOIUrl":"10.1016/j.ijrmhm.2024.106911","url":null,"abstract":"","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106911"},"PeriodicalIF":4.2,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527916","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}

{"title":"Preparation of ultrafine WC-V8C7-Cr3C2-co cemented carbides by spark plasma sintering in-situ synthesis of composite grain growth inhibitors","authors":"Hao Jiang ,&nbsp;Zhiwei Zhao ,&nbsp;Panjun Wang ,&nbsp;Xiaowei Liang ,&nbsp;Qiujun Hu ,&nbsp;Liuyang Bai ,&nbsp;Hongjuan Zheng ,&nbsp;Zheng Chen","doi":"10.1016/j.ijrmhm.2024.106910","DOIUrl":"10.1016/j.ijrmhm.2024.106910","url":null,"abstract":"<div><div>The growing high-precision manufacturing industry is increasing the demand for cemented carbide which has fine grain size and excellent machinability. In this research, ultrafine cemented carbide was successfully prepared by the method of <em>in-situ</em> synthesis using spark plasma sintering as densification method, V, Cr, WC and carbon black as raw materials. The formation mechanism of <em>in-situ</em> preparation of grain growth inhibitors (GGIs) and its influence on the properties of alloys were investigated. An excellent mechanical property (<em>H</em>_<em>V</em> 2254 kgf/mm², <em>K</em>_<em>IC</em> 9.20 MPa·m^1/2) and uniform microstructure of the alloys (0.8 wt% V₈C₇–0.8 wt% Cr₃C₂) prepared under 1350 °C, 6 min, 25 MPa were demonstrated by the results. The WC grain growth was significantly inhibited (about 200 nm). The <em>in-situ</em> synthesized GGIs significantly inhibited grain coarsening by interfering with the dissolution-precipitation process of WC during liquid-phase sintering. The combination of SPS and <em>in-situ</em> synthesized GGIs offers a novel approach to exploration of the preparation of high-performance ultrafine or nanocrystalline cemented carbides.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106910"},"PeriodicalIF":4.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419674","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}