[an error occurred while processing this directive]
[an error occurred while processing this directive]
Quick Search
Adv Search
2024 Vol. 29, No. 3
Published: 2024-06-15
Engineering and Technology
Theoretical Research
Review
Review
151
Research status and development prospect of extreme high-speed laser cladding technology
XIAO Mingying, FAN Zhenhong
DOI: 10.19976/j.cnki.43-1448/TF.2024023
As an alternative technology for electroplating and thermal spraying, extreme high-speed laser cladding technology has attracted more and more attention since its inception. The technical principle of extreme high-speed laser cladding was clarified by comparing with conventional laser cladding. The technical characteristics and advantages were analyzed by comparing with electroplating, thermal spraying, and conventional laser cladding. This work reviewed the current research status of extreme high-speed laser cladding, including equipment, material, process, microstructure, and application, etc., analyzed the shortcomings of this technology, and offered suggestions for the research and application development.
2024 Vol. 29 (3): 151-161 [
Abstract
] (
528
)
HTML
(0 KB)
PDF
(808 KB) (
255
)
Theoretical Research
162
First-principles calculation of electrochemical properties of Al/Mg co-doped Li
2
MnO
3
ZENG Zhiquan, ZHANG Shiwei, WANG Jianchuan
DOI: 10.19976/j.cnki.43-1448/TF.2024031
Dual-ion doping is an effective method to improve the electrochemical properties and cycle stability of Li
2
MnO
3
, a lithium-rich manganese-based cathode material. However, the influencing mechanism of the subtle interaction between doped ions on the performance of Li
2
MnO
3
is still unclear. This study investigated the lattice structure, electronic structure, O stability, and Li diffusion dynamics of Mg single doped and Mg/Al co-doped Li
2
MnO
3
through first-principles calculation. The results show that compared with Mg single doping case, Mg/Al co-doping can cause significant lattice distortion, enhance the electrochemical activity of local O, but also sacrifice some O stability, and promote the intralayer diffusion of local Li. This study highlights the differences in the effects of Mg/Al co-doping and Mg single doping on the electrochemical properties of Li
2
MnO
3
, providing a theoretical basis for optimizing the design of lithium-rich manganese-based cathode materials.
2024 Vol. 29 (3): 162-171 [
Abstract
] (
79
)
HTML
(0 KB)
PDF
(874 KB) (
86
)
172
Hot isostatic pressing forming performance of titanium alloy powder impeller disc
HE Shan, CAI Gaoshen, PAN Yufeng
DOI: 10.19976/j.cnki.43-1448/TF.2024028
Numerical simulation analysis was conducted on the hot isostatic pressing of titanium alloy powder to form impeller discs. The distribution of equivalent plastic strain and the variation of node density over time, as well as the distribution of relative density of pressed parts were studied, and impeller disc samples were prepared using hot isostatic pressing technology. The results show that the numerical simulation results show good consistency with the experimental data. This discovery fully demonstrates the effectiveness of numerical simulation technology in the hot isostatic pressing process of impeller discs, and the accuracy of predicting the forming characteristics. This not only provides strong data support for optimizing the production process of impeller discs, but also lays a solid foundation for the subsequent prediction of complex parts.
2024 Vol. 29 (3): 172-180 [
Abstract
] (
55
)
HTML
(0 KB)
PDF
(694 KB) (
82
)
Engineering and Technology
181
Effect of plasma boriding on diamond coating of cemented carbide surface
DING Sheng, WANG Hailong, MA Li, WEI Qiuping
DOI: 10.19976/j.cnki.43-1448/TF.2024029
After plasma boriding pretreatment, the diamond coating was deposited onto the surface of cemented carbide through hot filament chemical vapor deposition. The effects of pretreatmens on the growth quality and bonding properties of the diamond coating were investigated using scanning electron microscope, X-ray diffractometer, Raman spectrometer, and Rockwell hardness tester. The results indicate that as the plasma boriding temperature increases, CoWB content of the substrates surface increases while WC undergoes decarburization to form W. Plasma bombarding can increase the surface defect density of substrate and improve the nucleation rate of diamond. CoWB passivation layer and W transition layer can inhibit Co atom diffusion and improve the growth quality of diamond. Compared with an acid and alkali two-step method, the graphite phase content of diamond coating on cemented carbide surface after plasma boriding is significantly reduced, and the residual stress decreases with the increase of plasma boriding temperature. The reduction of graphite phase content and residual stress can improve the bonding properties between diamond coating and cemented carbide substrate, after pretreatment at 1 000 ℃, the bonding force of diamond coating on cemented carbide surface can reach the level of HF1.
2024 Vol. 29 (3): 181-190 [
Abstract
] (
58
)
HTML
(0 KB)
PDF
(1796 KB) (
79
)
191
Microstructure and ablation properties of ZrC nano-powder modified C/C-SiC composites
TANG Lei, BAI Kailun, XIONG Xiang, YIN Jian, ZHANG Hongbo, ZUO Jinlü
DOI: 10.19976/j.cnki.43-1448/TF.2024027
In order to improve the ablation resistance of C/C-SiC composites, ZrC nano-powder modified C/C-SiC composites were prepared by the reactive melt infiltration (RMI) with ZrC nano-powder and Si powder as raw materials. X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometer were used to investigate the effects of ZrC nano-powder contents on the microstructure and ablation properties of C/C-SiC composites. The results indicate that with the increase of ZrC nano-powder content, the porosity of the composite increases, but the density changes little. Meanwhile, part of ZrC nano-powders are diffusely distributed in the SiC matrix, and part of them are agglomerated. After ablation for 30 s, when the mole fraction of ZrC nano-powder is 6%, the composite exhibits the lowest mass and linear ablation rates of 2.0 mg/s and 3.9 μm/s, respectively. And with the increase of ZrC nano-powder content, the content of ZrO
2
formed during ablation increases, this leads to a notable enhancement in the pinning effect on SiO
2
, effectively improving the ablation resistance of C/C-SiC composites.
2024 Vol. 29 (3): 191-200 [
Abstract
] (
69
)
HTML
(0 KB)
PDF
(1928 KB) (
92
)
201
Gas carburization and mechanical properties of radial composite tungsten alloy rods
LI Bo, WANG Meng, YANG Mingchuan, LUO Rongmei, WU Hailong, DU Zhonghua
DOI: 10.19976/j.cnki.43-1448/TF.2024026
The surface heat treatment of a radial composite tungsten alloy rod was carried out by gas carburization method, and a carburized layer with a certain thickness was obtained on the surface. The effects of carburizing temperature and time on the microstructure and mechanical properties of the alloy were studied by scanning electron microscopy, X-ray diffraction, nanoindentation, and room temperature static compression experiments. The results show that in the range of 1 150-1 250 ℃, with the increase of carburizing temperature and time, the thickness of carburized layer increases obviously, and WC phase is fully formed. When the carburizing temperature is 1 200 ℃ and the carburizing time is 3-5 h, the thickness of the carburized layer of the alloy can reach 70.5-94.1 μm, and the Vickers hardness reaches 599.6-1 128.6. After carburization the radial composite tungsten alloy rod maintains good compressive toughness during compression at room temperature. When the carburized layer is thick, the outer material W70Cu undergoes obvious shear failure.
2024 Vol. 29 (3): 201-209 [
Abstract
] (
75
)
HTML
(0 KB)
PDF
(1087 KB) (
76
)
210
Effects of warm pressing temperature on the compression and magnetic properties of FeSiBC amorphous magnetic powder cores
LIU Shijie, GENG Zhaowen, CHEN Chao, LUO Wulin, ZHOU Kechao
DOI: 10.19976/j.cnki.43-1448/TF.2024025
High resistivity inorganic oxide nanoparticles are widely used as insulation materials for soft magnetic powder cores to reduce the eddy current loss at high frequency, as well as enhance the operational stability and energy utilization efficiency of the devices. In this research, the warm pressing process was introduced into the preparation of FeSiBC amorphous magnetic powder cores aiming at the problem that the presence of nonmagnetic oxide nanoparticles leads to a decrease in the densification and permeability of powder cores. It focused on the effects of warm pressing temperature on the formability, magnetic properties, and mechanical properties of FeSiBC amorphous magnetic powder cores. The results demonstrate that the softened resin can effectively fill the gap between the magnetic powders and enhance the bonding effect at a warm pressing temperature of 120 ℃, so that the powder core has the best compression performance and comprehensive magnetic properties. In this condition, the compressive strengths are 220.0 MPa and 269.1 MPa for the raw and coated powder cores, respectively, which are 107.5% and 47.8% higher compared to room temperature pressing powder core; the effective permeability stabilize to 20.8 H/m and 18.7 H/m in the range of 100 kHz-10 MHz, respectively, which are 20.9% and 16.9% higher compared to room temperature pressing powder core; the alternating current losses are 2 693.5 kW/m
3
and 2 228.0 kW/m
3
at 1 MHz and 0.05 T, respectively, which are 13.9% and 21.3% lower compared to room temperature pressing powder core. In this work, the optimized parameters in the warm pressing process are explored to enhancing the application frequency and energy utilization efficiency of magnetic powder cores, which provides insights for the preparation of FeSiBC magnetic powder cores with excellent performance.
2024 Vol. 29 (3): 210-220 [
Abstract
] (
98
)
HTML
(0 KB)
PDF
(921 KB) (
105
)
221
Preparation of foam SiC-based titanium suboxide electrode and the performance of electrocatalytic oxidation acid orange G
YU Zhangjun, WANG Xiang, DENG Zejun, MA Li, WEI Qiuping
DOI: 10.19976/j.cnki.43-1448/TF.2024030
Three dimensional foam SiC based titanium suboxide (SiC/Ti
n
O
2
n
-1
) electrode was prepared by sol-gel sintering method. The surface morphology, phase composition, and electrochemical property of titanium suboxide electrodes were characterized by scanning electron microscopy, X-ray diffraction, and electrochemical workstation. The degradation effect of organic pollutants was tested using a ultraviolet-visible spectrophotometer. The results show that the coating of foam SiC based titanium suboxide electrode prepared at 1 050 ℃/2 h sintering condition has good quality, continuous and uniform distribution, and the content of conductive phase Ti
4
O
7
is the highest (mass fraction is 37.5%), the film charge transfer resistance is the lowest (16.75 Ω). It shows a faster degradation rate (reaction rate constant is 0.60 h
-1
) and lower energy consumption (11.63 (kW∙h)/m
3
) for simulated pollutant acid orange G. Both •OH and $ \mathrm{SO}_{4}^{.-}$ are involved in the degradation of acid orange G, and their contributions to the removal of acid orange G are almost the same. The presence of inorganic ions $ \mathrm{HCO}_{3}^{-}$, $ \mathrm{NO}_{3}^{-}$, $ \mathrm{H}_{2} \mathrm{PO}_{4}^{-}$ has an inhibitory effect on the degradation of acid orange G, while Cl
-
promotes the degradation. The electrode exhibits high stability in multiple degradations.
2024 Vol. 29 (3): 221-230 [
Abstract
] (
69
)
HTML
(0 KB)
PDF
(1340 KB) (
71
)
231
Rare earth ion doping regulates the electronic structure of MIL-101 to promote electrocatalytic nitrogen reduction reaction
YANG Tonghui, YUE Song, GONG Weiwei, WANG Renqing, HU Weida, LIU Xiaopan, GAO Pengzhao, QIN Hang, GUO Wenming, XIAO Hanning
DOI: 10.19976/j.cnki.43-1448/TF.2024033
Electrocatalytic nitrogen reduction reaction (eNRR) is considered as an effective strategy for producing $NH_{3}/NH_{4}^{+}$ with low concentrations under environmental conditions, and designing appropriate catalysts is the key to efficiently driving eNRR. This study used a hydrothermal method to prepare MIL-101 catalyst and investigated the effects of hydrothermal temperature and Gd element doping on the eNRR performance of MIL-101 catalyst. The results show that 150-M-101 has the highest crystallinity and eNRR performance (NH
3
yield of 11.5 μg/(h·mg), Faraday efficiency of 30.5%). The surface of MIL-101-0.5Gd is concave, exposing the internal rough pore structure, improving the apparent activity of the catalyst. At the same time, the increase of oxygen vacancy concentration optimizes the characteristic activity of the catalyst, the NH
3
yield and Faraday efficiency at 0.1 mol/L LiClO
4
electrolyte and -1.3 V potential are 16.7 μg/(h·mg) and 37.6%, respectively, which are better than undoped 150-MIL-101. The catalyst also has good long-term stability.
2024 Vol. 29 (3): 231-245 [
Abstract
] (
62
)
HTML
(0 KB)
PDF
(1315 KB) (
92
)
246
Effects of annealing temperature on microstructure and mechanical properties of Ti-2Mn-2Sn-0.1B alloy by powder metallurgy
FANG Haoyu, WU Qiumei, YUAN Tiechui
DOI: 10.19976/j.cnki.43-1448/TF.2024041
Powder metallurgy process has significant advantages in production cost, freedom of composition design and so on, and is an effective way to manufacture low-cost and high-performance titanium alloys. In this paper, Ti-2Mn-2Sn-0.1B alloys were prepared by powder metallurgy, and the effects of annealing temperature on microstructure and mechanical properties of the alloy were studied. The results show that all of the Ti-2Mn-2Sn-0.1B alloys are composed of α, β, and TiB phases. Compared with the unannealed alloy, the β phase content in the alloy annealed at 750 ℃ increases, the flake and needle α′ phases are deposited in the alloy annealed at 850 ℃, and the α and β phases are distributed in layers in the alloy annealed at 950 ℃. All the alloys are mainly ductile fracture, and the alloy annealed at 950 ℃ has better mechanical properties, the layered α and β phase can provide good strengthening and hardening effects, and the microhardness (HV), ultimate tensile strength, and elongation are 335±16, (803±4) MPa, and (11.3±2.2)%, respectively.
2024 Vol. 29 (3): 246-254 [
Abstract
] (
73
)
HTML
(0 KB)
PDF
(1632 KB) (
71
)
[an error occurred while processing this directive]
[an error occurred while processing this directive]
