INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2025
·
IF 4.6
Taotao Cai,Ying Zhang,Shili Zheng,Longkai Liu,Yi Zhang,Bin Yu
V Al master alloys are essential raw materials for producing high-quality titanium alloys, which are generally produced by aluminothermic reduction, metal-slag gravitational separation method. The conventional way faces the challenges of excessively high reaction temperatures, metallic inclusions in slag, and difficulties in fabricating higher-Al-content alloy in one step. To conquer these issues, this research has reported a new method to precisely fabricate V Al master alloy with a designated composition, which is an aluminum reduction coupled with an acid leaching process. The reduction byproduct of weak-acid-soluble calcium aluminate, the critical parameters for Al reduction, and the reaction routes are determined. This research has demonstrated that various V Al master alloys (expressed as AlV x ) are successfully prepared by heating the optimal mixture of V 2 O 3 + (2 + 2 x -)/ x Al + 2.0CaO + 1.35CaCl 2 (in molar ratio) at 1000 °C for 5 h in Ar and pickling the reduction material using HCl acid with pH controlled at 1.2. Oxygen in 6Al4V, 4Al6V, and 2Al8V alloy powders are 400 ppm, 500–700 ppm, and 1800–2000 ppm, respectively. The 4Al6V powder produced by this reported method is compared with the commercial one, with comparable phase and chemical compositions but with finer sizes preferred in powder metallurgy sintering. The main reactions or phase changes that happen during heating include stepwise removal of surface and crystalline water from CaCl 2 , melting of Al, reaction between V 2 O 3 and CaO, melting of CaO-CaCl 2 binary compound, and Al reduction reaction. The method developed in this study can also be used to prepare other alloys, such as Ti Al and Ti Fe alloy powders.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2023
·Vol. 15
·期 6
·e202300217
·
IF 4.5
Shanshan Chai,Denglei Gao,Jing Xia,Yanpeng Yang,Xi Wang
Graphical Alloy catalyst for acetylene hydrogenation: A palladium-silver dilute alloy catalyst (Pd x Ag/Al 2 O 3 ) was fabricated and showed an outstanding performance for acetylene hydrogenation, which contains the Pd 1 Ag single-atom-alloy (SAA) and Pd 2 Ag dimer-alloys (DA) species. Selective hydrogenation of acetylene (C 2 H 2 ) to ethylene (C 2 H 4 ) has been recognized as an important strategic reaction for the removal of trace acetylene from ethylene. Palladium-based alloys are one of the most commonly used catalysts for this reaction but bear a high price and unsatisfactory catalytic performance. Here, we develop a feasible strategy toward the synthesis of a palladium-silver dilute alloy catalyst (Pd x Ag/Al 2 O 3 ), which contains the Pd 1 Ag single-atom-alloy (SAA) and Pd 2 Ag dimer-alloy (DA) species. This catalyst exhibits a high ethylene (C 2 = ) yield of 90.1 % even after 100 hours at 60 °C, which is 11.9 times higher than that of the PdAg/Al 2 O 3 alloy catalyst. Based on in-situ spectroscopic investigations and theoretical calculations, both Pd 1 Ag SAA and Pd 2 Ag DA species in Pd x Ag/Al 2 O 3 are easier to desorb C 2 H 4 compared with PdAg/Al 2 O 3 , and they experience the possible hydrogenation paths with the low energy barriers to yield C 2 = . Furthermore, Pd x Ag/Al 2 O 3 is beneficial to restraining coking due to the endothermic C−H bond cleavage. Thus, these combined merits contribute to the superior catalytic performance for Pd x Ag/Al 2 O 3 .
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2025
·
IF 5.5
Xinxin Xia,Cheng Zhang,Wenyi Lai,Zhenglin Zou,Peigen Zhang,Jingwen Tang,Ying Guan,Shuang Tian,Balázs Illés,ZhengMing Sun
The spontaneous growth of metal whiskers has long posed reliability challenges in electronic devices, often resulting in short-circuit failures. Recent findings on the rapid and extensive formation of tin (Sn) whiskers on Ti₂SnC substrates underscore the critical role of atomized Sn in whisker growth. In this study, mechanochemically decomposed Ti₂SnC, capable of quantitatively and efficiently generating large amounts of atomized Sn, was implanted to Sn, Bi, and Pb metal matrices. After three days of being annealed at 60 °C, numerous whiskers grown on all implanted matrices, proving the critical role of atomized Sn in whisker growth. Notably, SnBi bimetallic and solid solution whiskers were detected. TEM analysis proved that the formation of SnBi whiskers was caused by the released latent heat of crystallizing atomized Sn, which creates SnBi micro-melt pools at the interface, facilitating interface flow and supplying the necessary constituents for SnBi bimetallic and solid solution whisker formation. Likewise, SnPb bimetallic whiskers were observed in Pb matrices implanted with the mechanochemical decomposed Ti 2 SnC. These findings provide two contrasting strategies for future applications: effectively suppressing whisker formation and intentionally synthesizing bimetallic nanowires.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
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
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Liangcai Du,Qianqian Kong,Lichao Gong,Huachen Liu,Song Huang,Yunqi Xie,Zhenhua Yao
High entropy alloys (HEAs) exhibit distinctive core effects and excellent properties, presenting promising prospects for various applications, particularly as potential cermet adhesives. (Ti,W)C-HEA cermets were synthesized using vacuum sintering, employing mechanically alloyed CoCrFeNiTi HEA powder as a binder. The microstructure and mechanical properties of the produced cermets were systematically analyzed, with a particular focus on the effect of the HEA binder on the mechanical properties of the cermets. The findings indicated a decreasing trend in relative density, Rockwell hardness, and transverse rupture strength (TRS) of the cermets. Notably, the CM1 group ((Ti,W)C-30 wt% Co 20 Cr 20 Fe 20 Ni 35 Ti 5 ) demonstrated the most favorable overall properties, with values of 97.0 % for relative density, 83.2 HRA for Rockwell hardness, and 776.6 MPa for TRS. The phase transformation of HEAs at elevated temperatures was meticulously investigated using differential scanning calorimetry (DSC) and heat treatment. Combined with X-ray diffraction (XRD), the phase transformation of Co 20 Cr 20 Fe 20 Ni 25 Ti 15 and Co 20 Cr 20 Fe 20 Ni 15 Ti 25 , heat treated at increasing temperatures, is as follows: FCC + BCC (milled) → FCC + σ (700°C–1100 °C) → FCC (bulk).
研究领域:
材料科学
·
冶金学
✓ 已验证
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
MATERIALS CHARACTERIZATION
·
2022
·
IF 4.537
Z. Sun,X.X. Zhu,H.Z. Chen,L.X. Zhang
To address the excessive formation of brittle compounds when brazing TiAl alloys, a TiZrHfCoNiCu high-entropy brazed filler was developed to realize the brazing of TiAl/Ti 2 AlNb couples. The TiAl/Ti 2 AlNb brazed joints can be divided into 4 zones, i.e., 2 diffusion zones at the TiAl/braze filler, Ti 2 AlNb/braze filler interfaces and 2 zones divided inside the brazed seam. α 2 + γ-TiAl were the main reaction products formed at the TiAl/braze filler interface and α 2 + Ti 0.5 Al 0.12 Nb 0.38 were the main reaction products at the Ti 2 AlNb/braze filler interface. Effects of brazing temperatures on the interfacial microstructure and mechanical properties of the TiAl/Ti 2 AlNb brazed joints were investigated. When brazing at 1100°C/15 min, the highest shear strength can reach 157 MPa (room temperature), and 123 MPa (650°C) respectively. The relationship between the microstructure and the corresponding mechanical response were discussed in detail. This research can offer new insights on developing desirable brazing filler when joining TiAl and TiAl based alloys.
研究领域:
材料科学
·
焊接工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Yongyang Zhu,Shaoyang Shen,Xu-Sheng Yang,Liming Zeng,Gary Tsui,Zheng-Long Xu,Qing Zhou,Renheng Tang,K.C. Chan
Lithium borohydride (LiBH4) is a promising hydrogen storage material, but the irreversibility of hydrolysis and the high cost of regeneration have severely restrained its commercial applications. Herein, we reported a cost-effective method to regenerate LiBH4 by ball milling hydrous lithium metaborate (LiBO2·2H2O) with low-cost Mg-based alloys, instead of MgH2, under ambient conditions. An effective strategy is developed to improve the regeneration kinetics of LiBH4 by introducing the light rare-earth metals into Mg to facilitate the breakage of B–O and conversion of H+ into H–. A yield of 40% can be achieved for a relatively short ball milling duration (10 h) for the LiBO2·2H2O-CeMg12 system. The optimized regeneration of LiBH4 is believed to be efficient and economical since it utilizes an intrinsic hydrogen source in LiBO2·2H2O and cheap reducing agents. Our finding is expected to enable a wide deployment of LiBH4 for hydrogen storage.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2023
·
IF 6.4
Sijie Liu,Renda Wang,Li Wang,Fangfang Ge,Mengyu Gao,Yang Si,Bingsheng Li
In this work, static immersion and gravimetric methods were used to study the corrosion behavior of three common stainless steels and four Ni-based alloys in a NaCl–MgCl 2 –KCl mixed molten salt under vacuum atmosphere. The corrosion test was conducted at 700 °C, with a maximum exposure time of 100 h. Corrosion behavior was determined by measuring the mass loss of the sample at different time intervals and the corrosion rates at 100 h. The microstructure of the alloy was analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic force microscope (AFM), and X-ray diffraction (XRD). The results showed that stainless steels were generally more severely corroded than Ni-based alloys. 304 stainless steel and In800H exhibited the worst corrosion resistance, whereas Ni-based alloy In625 had the best corrosion resistance. Fe and Cr were dissolved in the molten chloride salts and reacted with the molten chloride salts. Mo played a positive role in suppressing the corrosion of the alloys in molten chloride salts by inhibiting the outward diffusion of the elements.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Defence Technology
·
2024
·
IF 5
Zhanjun Yang,Hao Liu,Li Mi,Xiaoqian Wang,Oisik Das,Zhong xuan Han,Lin Jiang
To investigate the differences in combustion and energy release characteristics of metastable intermolecular composite materials composed of aluminum alloys and polyvinylidene fluoride (PVDF) with different compositions, two types of alloys were selected: Al-Mg and Al-Si. Pure aluminum powder of the same size was also chosen for comparison. The PVDF-coated metal particle composites and the mixtures of PVDF with metal particles were prepared using electrospray (ES) and physical blending methods (PM), respectively. A systematic study was conducted on the morphology, compositional structure, combustion performance, energy release characteristics, and thermal reactivity of the fabricated composites and their combustion products through scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), combustion performance experiments, closed vessel pressure tests, and simultaneous thermogravimetric-differential scanning calorimetry (TG-DSC). The experimental results indicated that the PVDF-coated metal particles prepared by the electrospray method exhibited a distinct core-shell structure, with the metal particles in close contact with the PVDF matrix. Compared to the PM blended materials, the ES composites demonstrated superior combustion performance and energy release characteristics during combustion. Analysis of different metal fuel systems under identical preparation conditions revealed that Al-Mg and Al-Si fuels modulate the combustion and energy release properties of aluminum alloy-PVDF MICs through two distinct pathways.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Acta Metallurgica Sinica-English Letters
·
2024
·Vol. 37
·期 7
·1147-1160
·
IF 2.9
Cheng Bishan,Li Depeng,Xing Baikang,Hou Ruiqing,Jiang Pingli,Zhu Shijie,Guan Shaokang
Magnesium and its alloys have attracting rising attention as one of biodegradable metallic materials. However, the rapid corrosion and severe localized corrosion still hinder their extensive applications in clinics. In this study, micro-alloying of Ca (≤ 0.1 wt%) into Mg0.5Zn0.2Ge alloy developed in our previous work was explored to further enhance the corrosion resistance and alleviate the localized corrosion of the alloy. The results reveal that the addition of Ca leads to the transformation of the cathodic Mg 2 Ge phase in Mg0.5Zn0.2Ca alloy into anodic MgCaGe phase in Ca-containing alloys, thereby changing the galvanic couples in alloys during immersion. The preferential dissolution of MgCaGe phase promotes the participation of Ca and Ge into the formation of corrosion products, resulting in the enrichment of Ca and Ge in the outmost of corrosion product layer, which stabilizes and passivates the corrosion product layer on Mg alloy surface. Additionally, the enrichment of Zn at the corrosion interface seems to further hinder the corrosion of Mg matrix. All of these factors confer a slower and more uniform corrosion on Mg0.5Zn0.2Ge x Ca ( x < 0.1 wt%) alloy, which provides favorable candidates for the further processing to gain suitable biodegradable Mg alloys.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
Qi Zou,Qichi Le,Xingrui Chen,Yonghui Jia,Chunyan Ban,Tong Wang,Henan Wang,Ruizhen Guo,Liang Ren,Andrej Atrens
This paper investigates the microstructure, corrosion, electrochemical behavior, and the discharge performance of Gallium (Ga) alloyed Mg-Al-Zn alloys using the gravimetric method, electrochemical measurements, and battery test. The average grain size of AZ80–2.5Ga (Mg-8Al-0.5Zn-2.5Ga alloy) is 36% smaller than that of AZ80 (Mg-8Al-0.5 Zn alloy). The number and size of the Mg 17 Al 12 phase particles are smaller and more homogeneously distributed. Ga reduces the self-corrosion rate, increases the electrochemical activity and the discharge performance. The grain refinement generates many grain boundaries on the surface and promotes discharge performance. The decrease of the self-corrosion rate is attributed to the suppression of the protective film that inhibits the anode consumption. The AZ80–2.5Ga anode has the optimal discharge capacity of 1437 mAh g − 1 and anode efficiency of 61% at 50 mA cm −2 , which are 25% and 29% higher than for the AZ80 anode.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）