Journal of Materials Research and Technology-JMR&T
·
2024
·
IF 6.2
Ruxia Liu,Wei Zhao,Ye Tian,Jian Zhang,Guoqiang Luo,Qiang Shen
TaC enhancement particles and Re alloy were used to improve the strength and ductility of the tungsten alloy. The synergetic effect of TaC addition and Re alloying on relative density, microstructure, and mechanical properties of tungsten alloy were investigated. The results indicated that a W-based composite with 2.5 wt% TaC addition and 25 wt% Re alloying exhibited yield stress of 1.23 GPa, the ultimate compressive stress of 2.86 GPa, bending strength of 1.30 GPa and strain capacity of 42 %, which was increased by 114 %, 140 %, 226 %, and 133 % than those of pure W. Further analysis revealed that the grain boundary purification, grain refinement, and kinematic strain gradient contribution because of the addition of TaC, lattice distortion, and the generation of dislocations because of the addition of Re alloying are the main strengthening mechanisms in W–TaC-Re composite.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2016
·
IF 2.647
S. Miao,Z.M. Xie,T. Zhang,X.P. Wang,Q.F. Fang,C.S. Liu,G.N. Luo,X. Liu,Y.Y. Lian
In this paper, hot rolled W-0.5 wt% TiC alloys are fabricated via a combination of powder metallurgy and subsequent hot rolling with 65% thickness reduction. The as-rolled alloys show high strength of 789 MPa at 200 °C with a total elongation of 4.8%. We have explored the mechanical properties and thermal stability of W-0.5 wt% TiC alloys after annealing at various temperature. The corresponding results show that hardness and fracture strength slightly decrease with increased annealing temperature up to 1500 °C owing to recovery. While after annealing at 1600 °C for 1 h, the fracture strength of W-0.5 wt% TiC alloys decreases significantly due to full recrystallization and grain growth. The thermal conductivity increases with increased annealing temperature. The observed incubation time for recrystallization and the corresponding recrystallization thermal activation energy (~612 kJ/mol) for this rolled plates indicate a sufficient thermal stability at service temperature below 1200 °C. This good thermal stability is attributed to the nanosized TiC dispersion strengthened structures.
研究领域:
材料科学
·
力学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2015
·
IF 1.989
Z.M. Xie,T. Zhang,R. Liu,Q.F. Fang,S. Miao,X.P. Wang,C.S. Liu
Dense fine-grained pure W, W–1.0 wt.%Zr (WZ), W–1.0 wt.%ZrC (WZC) and W–1.0 wt.%Zr–1.0 wt.%ZrC (WZZC) alloys were fabricated by spark plasma sintering . The grains in WZ and WZZC alloys are stable at annealing temperatures below 1400 °C (1 h), while the grains in pure W grow significantly above 1100 °C annealing. The tensile tests indicate that WZ is ductile already at 400 °C, which is about 200 °C lower than that for pure W. WZC exhibits higher hardness at room temperature than pure W. The ultimate tensile strength of WZC at 600 °C is 798 MPa, about 2.6 times that of pure W. Based on microstructural analysis , the good thermal stability of tungsten grains in WZ and WZZC samples is suggested to be originated from the W–Zr–O and/or Zr–C–O particles which are dispersed on or near the grain boundaries of tungsten and inhibit their migration. The improved tensile properties of the WZ, WZC and WZZC alloys originate (i) from the enhanced GB cohesion by Zr micro-alloying and (ii) from dispersion strengthening by nano-sized ZrC particles.
研究领域:
材料科学
·
金属学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2020
·
IF 3.407
Longqing Chen,Wenbin Qiu,Hao Deng,Xiaoliang Yang,Yangyipeng Song,Jun Zhu,Jun Tang
The shrinkages presented in sintering process of tungsten alloys are extremely detrimental to their practical applications in fusion reactors. Positively in this work, we effectively reduced the shrinkages via synergistically applying Ti-doping and annealing process on tungsten‑potassium (WK) alloys. This shrinkage-fill effect only works in the one with trace amount of titanium doping, such as 0.05 wt%Ti or 0.5 wt%Ti. Due to such effect, the compressive strength was improved by ~18%. Based on morphological and elementary analyses, we speculated that the Ti-rich particles along the grain boundaries of WK alloys were activated and migrated into shrinkages during annealing. Further Ti doping (e.g. 1wt.%Ti) led to nanoscale grain refinement in WK alloys, which almost doubled the compressive strength. In this case, an unconventional grain-refinement model was proposed. Furthermore, anomalous grain growth was observed in WK-3wt.%Ti, which was attributed to the formation of Ti-rich regions and the corresponding raise of energy in grain boundaries. The fabricating strategies in this work may benefit the design of refractory tungsten alloys with less shrinkages and ultra-fine grains.
研究领域:
材料科学
·
核能工程
✓ 已验证
产品关联
DOI
高影响因子
Radiation Effects and Defects in Solids
·
2024
·
IF 1.1
X.L. Ren,G. Yao,L.M. Luo,Y. Xu,A. Yabuuchi,Q. Xu
In the present study, we developed Mo- and Zr-added W-Y2O3 composites, and investigated their surface damage, including commercially available W induced by He and D as well as He and D mixture plasmas. Blistering was not observed in the D-plasma-irradiated W and W composites. The thickness of the damaged surface layer due to He plasma exposure of the W-Mo-Y2O3 composite was similar to that of W. However, the thickness of the damaged surface layer of the W-Y2O3 composite was half that of W. In addition, the thickness of the damaged surface layer of the W-Zr-Y2O3 composite was further improved by 5 times. Y2O3 nanoparticles, especially refined Zr-Y-O nanoparticles, act as He trap sites to suppress the formation and growth of He bubbles. Furthermore, the W-O-Y and W-O-Zr-Y nanoparticles increased the solubility of He and delayed He diffusion, hindering the formation of He bubbles.
研究领域:
材料科学
·
核能工程
✓ 已验证
产品关联
DOI
高影响因子
RARE METALS
·
2020
·Vol. 40
·期 7
·1940-1948
·
IF 2.161
Li Jia-Xin,Chen Yu-Hong,Bai Zhang-Jun,Zhao Bao-Jun,Jiang Liang,Wu Lan-Er
Ta–W alloys have unique properties but their applications at high temperatures are restricted due to their poor oxidation resistances. The addition of Al and Ti decreases the oxidation rate of the alloy, as Al-contained protective oxide layer could be formed. In this study, ternary and quaternary Ta–W alloys containing Al and Ti were prepared by hot press sintering. The microstructures and oxidation behaviors of the alloys were studied at 1173 K. The results show that the oxidation kinetics of all alloys follows a parabolic law at short oxidation periods. After cyclic oxidation, the kinetics of quaternary alloys still obeys the parabolic law but that of ternary alloy has been changed into linear law kinetics after 8-h oxidation. For ternary alloy, an outer layer with dense and continuous alumina was formed during the initial stage, and phase transformation caused the oxides to peel off. By comparison, the quaternary alloys depicted continuously solid solution of the oxides layer. Overall, Al and Ti played key roles in oxidation degree and affected the oxidation kinetics of ternary and quaternary alloys.
研究领域:
材料科学
·
金属学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2025
·
IF 6.6
Y. He,S.W. Xin,Y.P. Lin,L.W. Kong,K.K. Wen,X. Shen,X.C. Cai,B.R. Sun,T.D. Shen
The preparation of bulk nanocrystalline (NC) tungsten alloys with excellent thermal stability and ultrahigh strength at elevated temperatures is a challenge. In this study, bulk NC W-3at%Y (W-3Y) with an average grain size of 16 ± 4 nm was successfully prepared via mechanical alloying and high-pressure/high-temperature sintering. The NC W-3Y alloy not only has ultrahigh Vickers hardness of 22.0 ± 0.3 GPa - which is close to the hardness of ceramic tungsten carbide, but also can maintain high hardness of 16.0 ± 0.2 GPa and a small grain size of 37 ± 12 nm after annealing at 1300 °C for 50 hours. The compressive strength of NC W-3Y at 900, 1000, and 1100 o C are as high as 1116, 571, and 345 MPa, respectively, much higher than those of previously reported tungsten and tungsten alloys. Doping Y into W increases the GB diffusion activation energy, lowers the GB diffusion coefficient and in turn the GB sliding rate, and thus increasing the strength at elevated temperatures. Partial alloying Y element segregated at grain boundaries (GBs) reduces the GB energy, leading to an excellent thermal stability, as revealed by our experimental observation and theoretical calculation. The utilization of high pressure has direct and indirect effects on lowering the grain growth rate of W-3Y during sintering: directly reducing diffusion coefficient, indirectly enhancing the plastic deformation, thus shortening the atomic diffusion distance required to fill the gaps between powder particles and leading to a lower sintering temperature.
研究领域:
材料科学
·
金属学
✓ 已验证
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2023
·
IF 4.7
Weiqiang Hu,Lianfeng Wei,Jun He,Songhua Chen,Shaocun Liu,Zongqing Ma,Yongchang Liu
In this work, we creatively introduced MAX additives (Ti 2 AlC) into W alloy system to break the development bottleneck of ball milling technology: a large amount of oxygen impurities and large-sized second phase particles at grain boundaries (GBs). Unlike traditional oxides/carbides, Ti 2 AlC can undergo self-decomposition during high-temperature sintering stage (>1400 °C) on the basis of hydrogen sintering, and continue to adsorb a number of stubborn oxygen impurities to form various smaller, more dispersed, and stronger in-situ Ti x C y , TiO x , Al 2 O 3 , and Al x Ti y O z nanoparticles . Furthermore, these in-situ nanoparticles could maintain stable coherent interfaces with W, thereby more effectively refining, purifying, and strengthening matrix. Compared to traditional W-carbide/oxide alloys, MAX additives render our alloy with high hardness (521 ± 24 HV 0.2 ), a remarkable combination of high compressive strength (1262.9 ± 35.1 MPa) and large ductility (9.88%). This work provides a new perspective for the preparation of high-performance refractory metals and relevant engineering application.
研究领域:
材料科学
·
金属材料
·
纳米材料
·
粉末冶金
·
结构合金
✓ 已验证
DOI
高影响因子
PLASMA SCIENCE & TECHNOLOGY
·
2015
·Vol. 17
·期 12
·1066
·
IF 0.579
Zhuoming Xie,Rui Liu,Qianfeng Fang,Tao Zhang,Yan Jiang,Xianping Wang,Changsong Liu
W-(0.2, 0.5, 1.0)wt% ZrC alloys with a relative density above 97.5% were fabricated through the spark plasma sintering (SPS) method. The grain size of W-1.0wt% ZrC is about 2.7 μm, smaller than that of pure W and W-(0.2, 0.5)wt% ZrC. The results indicated that the W-ZrC alloys exhibit higher hardness at room temperature, higher tensile strength at high temperature, and a lower ductile to brittle transition temperature (DBTT) than pure W. The tensile strength and total elongation of W-0.5wt% ZrC alloy at 700 °C is 535 MPa and 24.8%, which are respectively 59% and 114% higher than those of pure W (337 MPa, 11.6%). The DBTT of W-(0.2, 0.5, 1.0)wt% ZrC materials is in the range of 500°C–600°C, which is about 100 °C lower than that of pure W. Based on microstructure analysis, the improved mechanical properties of the W-ZrC alloys were suggested to originate from the enhanced grain boundary cohesion by ZrC capturing the impurity oxygen in tungsten and nano-size ZrC dispersion strengthening.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Xingzhan Yuan,Shi Hong,Jing Wang,Bing Ma,Yifan Zhang,Man Niu,Laima Luo,Yucheng Wu
In this study, we propose a model to evaluate the ductile-to-brittle transition (DBT) of W based alloy using small tensile test and dislocation density measurement. The new model is built upon the high correlation between the DBT and the dislocation multiplication. Compared the measured results from the typical testing methods such as small tensile test, three-point bending test, it reveals that the new model is close to the bending test results. Interestingly, the equivalent transition temperature (ETT) of W-Y 2 O 3 alloy measured by three-point bending test and the new model is lower than that of pure W. The effect of grain boundary and Y 2 O 3 particles on DBT were discussed, and the lower transition temperature of W-Y 2 O 3 alloy is attributed to the easier dislocation multiplication near grain boundary as well as the increase of small angle grain boundary.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2023
·
IF 3.6
Yanan Wang,Man Wang,Honghong Sun,Kangyao Tang,Xiaoli Xi,Zuoren Nie
Oxide dispersion strengthened tungsten (ODS-W) alloys are promising plasma facing material in future fusion reactors. In this study, composite powders of W-Er 2 O 3 were prepared by co-deposition method and hydrogen reduction, and then consolidated by spark plasma sintering (SPS). Microstructure evolution during co-deposition process was investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and Fourier transform infrared spectrometer (FTIR). Also, simulation using DMol3 module in Materials Studio was carried out to understand the co-deposition mechanism. The results showed that H + of W-OH bond in white tungstic acid was replaced by Er 3+ due to coordination reaction during co-deposition process, leading to formation of ring-like chelate of (WO) n Er. This indicates that doping of Er 3+ was achieved at a molecular level. Consequently, Er 2 O 3 particles were relatively uniformly distributed in W-Er 2 O 3 alloy, and the hardness and compressive strength reached 627 ± 19 HV and 1640 ± 40 MPa, respectively.
研究领域:
材料科学
·
核能工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2025
·
IF 7
Yu He,Shengwei Xin,Baoru Sun,Xuecheng Cai,Yapeng Lin,Lingwei Kong,Xun Shen,Congcong Du,Xiaoyuan Yuan,Kangkang Wen,Tongde Shen
Metals are often soft while ceramics are often hard. To make metals as hard as ceramics has been long-awaited in metals and ceramics communities. In this study, bulk nanocrystalline (NC) tungsten-1 wt% yttrium-0.7 wt% titanium (WYT) was fabricated via mechanical alloying followed by high-temperature/high-pressure sintering. The high pressure directly inhibits grain growth by suppressing atomic diffusion and indirectly inhibits grain growth by lowering sintering temperature, enabling the synthesis of dense NC WYT bulks with an average grain size of ∼ 9.0 nm. The high temperature causes annealing- and segregation-induced structural relaxation of grain boundaries (GBs) in sintered bulk NC WYT, resulting in GBs with a small excess volume of only ∼ 0.005 nm, one fifth that of bulk NC tungsten. The small grain size and the relaxed GBs in the bulk NC WYT make it hard for GBs to emit dislocations, resulting in extremely high hardness of 23.2 ± 0.3 GPa, yield strength of 9.4 ± 0.3 GPa, and ultimate compressive strength of 13.1 ± 1.1 GPa. The hardness of metallic bulk NC WYT is comparable to that of ceramic tungsten carbide (WC) whereas the wear rate of bulk NC WYT is even lower than that of WC. The structure-relaxed GBs lower the thermodynamic driving force for grain growth and result in an extremely high thermal stability - no grain growth occurs in bulk NC WYT annealed at a high temperature of 1500 °C, which is above the recrystallization temperature of tungsten. The present strategy - multifunctional treatments of NC alloy powders by high-temperature/high-pressure - provides a huge potential to manufacture dense bulk NC materials with exceptional mechanical property and thermal stability for practical applications.
研究领域:
材料科学
·
金属学
✓ 已验证
产品关联
DOI
高影响因子
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