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2022 Vol. 27, No. 1
Published: 2022-02-15
Engineering and Technology
Theoretical Research
Review
Review
1
Research progress of synergistic reinforced copper matrix composites prepared by powder metallurgy
BAO Rui, ZHANG Wenfu, YI Jianhong, GUO Shengda
DOI: 10.19976/j.cnki.43-1448/TF.2021091
Copper materials occupy an important position in modern industry, but it is limited by performance shortages such as strength, wear resistance and stability, etc. Therefore, introducing the reinforcement into the copper matrix to prepare copper composite materials with excellent comprehensive performance through powder metallurgy technology has become a hot spot in the field of copper materials research. Even, multi-component and multi-scale synergistic enhancement is employed to design copper-based materials and obtain copper-based composite materials with better comprehensive performance to meet the requirements of more application fields. This paper reviews the research progress of common synergistically strengthened copper matrix composites, the method of introducing the reinforcing phase into the copper matrix, the synergistic enhancement effect, and mechanism, etc. At last, the development direction of synergistically strengthened copper matrix composites and the problems that need to be solved are given.
2022 Vol. 27 (1): 1-12 [
Abstract
] (
1699
)
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2639
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Theoretical Research
13
Phase equilibrium investigation of the Fe-Nb-Si ternary system
NIE Yusong, WEN Andong, ZHANG Ligang, DENG Zixuan, LIU Libin
DOI: 10.19976/j.cnki.43-1448/TF.2021086
Because of high coercivity, low permeability and large resistivity, silicon steel is widely used in the manufacture of iron core materials for transformers and various motors. On the basis of silicon steel, the addition of Nb element can improve the electromagnetic properties of silicon steel, and at the same time refine the grains and improve its mechanical properties. The research and application of Fe-Nb-Si ternary alloy is based on the study of ternary phase diagram. X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe microanalysis (EPMA/WDS) were used to analyze the Fe-Nb-Si ternary system at 1 173 K and 1 073 K. The following phase equilibrium was experimentally investigated. The results show that 11 three-phase equilibrium zones are measured at two temperatures, and three ternary compounds τ
2
(FeSi
2
Nb
2
)、τ
5
(Fe
4
Si
7
Nb
4
)、τ
6
(FeSiNb)are found. Themaximum solid solubility of Nb in η phase (Fe
5
Si
3
) is about 1.6% (mole fraction, %, the same below) at 1 173 K and 0.5% at 1 073 K. The maximum solid solubility of Fe in αNb
5
Si
3
is about 5.8%at 1 173 K and 4.9% at 1 073 K. The maximum solid solubility of Si in Fe
2
Nb is 24.3% at 1 173 K and 25.2% at 1 073 K. The maximum solid solubility of Si in μ phase (FeNb) is up to 13.4% Si at 1 173 K and only about 11.3% at 1 073 K. This work improves the phase diagram information of the Fe-Nb-Si ternary system and provides a theoretical basis for the subsequent development of new silicon steel.
2022 Vol. 27 (1): 13-23 [
Abstract
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710
)
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1299
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Engineering and Technology
24
The microstructure and mechanical properties ofAl-4.5Cu alloy fabricated by spark plasma sintering
MU Dikunqi, CAO Lei, ZHANG Zhen, LIANG Jiamiao, ZHANG Deliang, WANG Jun
DOI: 10.19976/j.cnki.43-1448/TF.2021088
Al-4.5Cu (mass fraction, %) alloy was prepared by spark plasma sintering (SPS) followed by solution, quenching and aging. The X-ray diffraction, scanning electron microscopy, transmission electronmicroscopy and tensile tests were carried out. The effect of interparticle boundary (IPB) and precipitation behavior on mechanical properties of the Al-4.5Cu alloy were investigated in detail. The results show that the IPB consists of Al
2
O
3
nanoparticles, CuAl
2
phase and residual nanopores. After T6 aging, coarse CuAl
2
phases with a diameter of 150-600 nm precipitate at the IPB, and the precipitation free zone (PFZ) with a width of 40-60 nm is formed. An improvement of yield strength and ultimate tensile strength from 95 MPa and 229 MPa to 280 MPa and 378 MPa is achieved respectively after T6 aging, while the elongation to fracture decreases from 11.8% to 6%. The increase in strength is mainly due to the well dispersion of precipitates and the densification of the material during T6 aging. The decrease in plasticity may result from the earlier plastic deformation in the PFZ during tensile deformation, leading to the accumulation of dislocations from PFZ to CuAl
2
phase nearby the IPB, as a result, stress concentrationis formed, which consequently promotes cracksexp and along the IPB and decreases the ductility of the material.
2022 Vol. 27 (1): 24-33 [
Abstract
] (
681
)
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715
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34
Effect of Cr content on microstructure and properties of ZK30-0.2Cu-Cr alloys prepared by microwave sintering
XU Yan, ZHANG Zhizhen, JI Jie, JIA Yunyi, WU Jiani, PEI Yingluo, JI Hairui, ZHAO Mingchun
DOI: 10.19976/j.cnki.43-1448/TF.2021073
Using ZK30 powders, copper powders and Cr powders as raw materials, ZK30-0.2Cu-Cr alloy with Cr content of 0-0.40% (mass fraction, the same below) was prepared by microwave sintering. The microstructure of the alloy was observed and analyzed by metallographic microscope, scanning electron microscope and X-ray diffracto meter. The mechanical properties, degradability, antibacterial properties and biocompatibility of the alloy were determined as well. The effect of Cr content on the microstructure and properties of ZK30-0.2Cu-
x
Cr alloy was studied. The results show that the hardness of the alloy increases with the increase of the solid solubility of Cr in the matrix. With the increase of Cr content, the biodegradation rate fluctuates. When
w
(Cr) is 0.1%, a Cr
2
O
3
oxide film forms on the alloy surface to protect the matrix from corrosion, and the biodegradation rate of the alloy reaches the lowest. But when
w
(Cr) exceeds 0.1%, the solid phase diffusion is not complete, and the residue of Cr element increases galvanic corrosion. Itadversely affects the corrosion resistance of the alloy and increases the biodegradation rate. In addition, all of the ZK30-0.2Cu-
x
Cr alloys have good cytocompatibility and antibacterial ability (antibacterial rate > 93%). Among them, ZK30-0.2Cu-0.05Cr has the best antibacterial performance with antibacterial rate as high as 99.38%. Taken into account, ZK30-0.2Cu-0.1Cr alloy has good mechanical properties, appropriate degradation rate, excellent cytocompatibility and antibacterial properties, so it is a potential antibacterial biological implant material.
2022 Vol. 27 (1): 34-44 [
Abstract
] (
768
)
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(797 KB) (
538
)
45
Microstructures and mechanical properties of 5083 aluminum alloy repaired by laser directed energy deposition
ZHU Hongbin, HUA Qian, LI Ruidi, XU Rong, LIN Zeheng, NIU Pengda, YUAN Tiechui
DOI: 10.19976/j.cnki.43-1448/TF.2021095
In this paper, the slotted 5083 aluminum-magnesium alloy was repaired by laser direction energy deposition (DED) method, in which Al-Mg-Sc-Zr alloy powders was used as the repairing material. The microstructure and mechanical properties of 5083 alloy samples before and after repairing were studied by means of metallurgical microscope, scanning electron microscope, electron backscatter diffraction, room temperature tensile test and microhardness measurement, etc. Meanwhile, the mechanical properties of samples with different repairing volumes were compared. The results show that the columnar crystals near the fusion line in the repaired area are dendritic and grow epitaxially to the matrix perpendicular to the fusion line. The repaired zone shows a typical molten pool distribution with grain size of 4-9 μm and abundant pores. A large number of Al
3
(Sc,Zr) particles are precipitated near the fusion line and scanning orbit. The tensile strengths of the 5083 matrix material and the grooved restorations are not much different, which are 190.80 MPa and 197.73 MPa, respectively, but the elongation of the repaired specimens is greatly reduced. In the range of 2 mm from the matrix to the repaired zone, the average hardness (HV) value increases gradually from 50 to 100.
2022 Vol. 27 (1): 45-55 [
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829
)
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1798
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56
Microstructure and properties of high-throughput in situ network structure TiC reinforced TC4 composite materials
DU Kanghong, LIU Zhongqiang, ZHANG Jiantao, WEN Liping, XIAO Zhiyu
DOI: 10.19976/j.cnki.43-1448/TF.2021070
Using TC4 alloy powders with different particle sizes as the matrix material, using VC as the carbon source, using high throughput hot press sintering process, TiC/TC4 composites were prepared with different network structure sizes and TiC volume fractions (2%, 4%, 6%). The effect of TiC content and TC4 powder particle sizes on the microstructure and properties of composite materials were studied. The results show that the TiC reinforcement particles in TiC/TC4 titanium matrix composites are distributed in a network. Compared with TC4 alloy, the microstructure of TiC/TC4 composite materials are significantly refined. As the TiC content increases, the thickness of the TiC network layer increases, and the tensile strength and elongation of the material first increase and then decrease. The material with 2%TiC has the best overall performance. As the particle size of TC4 decreases, the microstructure of the TiC/TC4 composite is gradually refined, the connectivity of the matrix increases, and the tensile strength and elongation of the material increase at the same time. 2%TiC/TC4 composite material prepared by TC4 alloy powders with a particle size of 40-80 μm has a small network structure and the best overall performance. The yield strength, tensile strength and elongation reach 946 MPa, 1058 MPa and 18.1%, respectively, which are 29.6%, 31.6%, and 118.1% higher than TC4 alloy.
2022 Vol. 27 (1): 56-65 [
Abstract
] (
937
)
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1192
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66
Optimization of process parameters for selective laser melting of Cu-Cr-Nb alloy
REN Yake, LIU Zuming, ZHANG Yazhou, AI Yongkang, YE Shupeng, LI Jian, PENG Weicai
DOI: 10.19976/j.cnki.43-1448/TF.2021052
Cu-1.93Cr-0.74Nb (mole fraction, %) alloy was prepared by selective laser melting (SLM) using Ar-gas atomized powders. The effects of laser power, scanning speed and scanning spacing on the relative density, molten pool morphology, and microstructure of as-built samples were investigated. The results show that the effects of SLM process parameters on the relative density, metallurgical defects and microstructure of as-built Cu-1.93Cr-0.74Nb alloy are nonlinear. The relative density of as-built sample increases first and then decreases with increasing the laser power from 300 W to 400 W, or the scanning speed from 500 mm/s to 1 100 mm/s. The number and size of pore also shows a similar change rule. The relative density is closely related to the continuity of melting pool, the number and size of pore. The relative density of as-built Cu-1.93Cr-0.74Nb alloy prepared by optimum parameters of the laser power of 330 W, the scanning speed of 800 mm/s and the scanning space of 0.1 mm, reaches 99.3%. It has a bimodal core-shell structure and a strong {110} texture with a large-sized grain as the center and fine grains distributed on the shell. The texture index and texture strength are 9.319 and 7.812, respectively.
2022 Vol. 27 (1): 66-76 [
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] (
775
)
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77
Interface performance of Ni/Bi
0.4
Sb
1.6
Te
3
thermoelectric material
KUANG Zhixiang, MA Yan, XU Chenhui, KONG Dong, FENG Bo, FAN Xi'an
DOI: 10.19976/j.cnki.43-1448/TF.2021085
The barrier layer between the Bi
0.4
Sb
1.6
Te
3
thermoelectric material and the metal electrode is the controlling factor for the stable service of the thermoelectric device. In this paper, the spark plasma sintering diffusion welding method was used to prepare a Ni layer on the Bi
0.4
Sb
1.6
Te
3
surface as a barrier layer for the Ni/Bi
0.4
Sb
1.6
Te
3
electrode joint, in which high-density Ni foil and Bi
0.4
Sb
1.6
Te
3
alloy were used as the raw materials. The phase analysis of the barrier layer was performed using X-ray diffractometer. The interface morphology and element distribution of the electrode joints were analyzed by the scanning electron microscope and its energy spectrometer. The results show that the Ni foil annealed at 700 ℃ has excellent anti-diffusion effect, and the diffusion thickness is as low as 9 μm. The Ni foil annealed at 700 ℃ is combined with Bi
0.4
Sb
1.6
Te
3
by diffusion welding to obtain a bonding strength of 13.19 MPa. As the annealing temperature of Ni foil increases, Ni/Bi
0.4
Sb
1.6
Te
3
interface cracks are significantly improved. This is because the lattice mismatch between Ni/Bi
0.4
Sb
1.6
Te
3
can be improved with the incresing annealing temperature of Ni foil, thereby the connection performance of the Ni layer and Bi
0.4
Sb
1.6
Te
3
is improved.
2022 Vol. 27 (1): 77-82 [
Abstract
] (
663
)
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(483 KB) (
803
)
83
Electrochemical properties of two-site coordination polymer modified Co-free Li-rich manganese-based cathode
ZHANG Siyu, CHEN Minjian, MA Cheng, ZHANG Chunxiao, WEI Weifeng
DOI: 10.19976/j.cnki.43-1448/TF.2021077
Using cobalt-free Li
1.2
Mn
0.53
Ni
0.27
O
2
(LMNO) cathode material and Acetoacetate ethylene glycol methacrylate (AAEM) as raw materials, in-situ solution polymerization of AAEM was used to form an organic coating layer on the surface of cobalt-free LMNO cathodematerial to improve its cycling stability and interfacial stability. The influence of AAEM on LMNO layered cathode materials were studied using Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and Electrochemical Impedance Spectroscopy (EIS), etc. Theresults show that the capacity retention rate of the modified sample is as high as 82% after 300 cyclesat 1C cycle within the voltage range of 2-4.7 V, which is much higher than that of the pristine sample (67% after 300 cycles).The refore, the coordination group on the double-site chelating polymer layer can coordinate with the Transition Metal (TM) ion, which enhances the electrode/electrolyte interfacial stability, increases the cycle stability of cathode materials, and improves the electrochemical performance of the material.
2022 Vol. 27 (1): 83-91 [
Abstract
] (
820
)
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(885 KB) (
1378
)
92
Microstructure and mechanical properties of rapid prepared C
f
/SiC composites
WANG Yang, LI Guodong, YU Shijie, JIANG Yi
DOI: 10.19976/j.cnki.43-1448/TF.2021083
C
f
/SiC ceramic matrix composites were prepared byslurry brushing-needle punching-warm pressure curing- high temperature carbonization proces using SiC powders, alcohol-soluble phenolic resin powders, carbon fiber felt and carbon fibers weft free cloth as raw materials. The C
f
/SiC porous preform was prepared by slurry brush coating, puncture, temperature pressure curing and high temperature carbonization. The volume fraction of phenolic resin in the slurry was respectively 10% and 15%, and temperature and pressure curing pressures was 8 MPa and 20 MPa, respectively. And then SiC was deposited by chemical vapor infiltration method to quickly prepare C
f
/SiC ceramic matrix composites. The morphology and microstructure of the materials were observed and analyzed. The properties such as density, porosity, bending strength and fracture toughness of the materials were measured. The results show that the properties of C
f
/SiC composites are better when the volume fraction of phenolic resin in the slurry is low, and the properties increase with the increase of curing pressure. When the volume fraction of phenolic resin was 10% and the curing pressure was 20 MPa, a high density C
f
/SiC composite with open porosity of 13.1% is obtained. The matrix of C
f
/SiC composite was relatively compact, and there was almost no pores between the fiber bundles and the matrix. When the composite was subjected to the applied load, the strength and toughness of the composite were improved by fiber pulling out, fiber debonding and crack deflection. The fracture mode of the composite was pseudoplastic fracture, with the highest bending strength and fracture toughness of 570 MPa and 18.6 MPa·m
1/2
, respectively.
2022 Vol. 27 (1): 92-101 [
Abstract
] (
694
)
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(1124 KB) (
848
)
102
Preparation and properties of biodegradable Fe-Mn alloy by injection molding
ZHANG Ye, LI Dongyang, LI Yimin, LUO Fenghua, SHU Chang, LI Song
DOI: 10.19976/j.cnki.43-1448/TF.2021089
Fe-Mn alloy as a kind of biodegradable material has attracted extensive attention owing to its good mechanical properties and biocompatibility. In this paper, the Fe-
x
Mn (
x
=25, 30, 35,mass fraction, the same below) alloys were prepared by injection molding. The effect of sintering time on the microstructure, mechanical properties and in vitro static degradation properties of Fe-Mn alloys was studied. The results show that sintering time has few effects on the phase composition of Fe-Mn alloys. However, Mn content affects the phase composition of the alloys. Fe-35Mn alloys are mainly composed of austenite. The average grain size of Fe-Mn alloys prepared by injection molding is about 10-20 μm, and Mn loss is about 5.8%-10.82% on the surface. When the sintering time is 7 h, the Fe-35Mn alloy possesses the optimal mechanical properties involving the tensile breaking strength of 358 MPa and the elongation of 10.83%. The 30-day static immersion degradation tests show that the degradation rate of the alloy is 1 mm/y after soaking for one day, and gradually decreases with the accumulation of corrosion products.
2022 Vol. 27 (1): 102-110 [
Abstract
] (
793
)
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850
)
111
Microstructure and mechanical property of Al-Zn-Mg-Cu aluminum alloy substrate repaired by laser directed energy deposition with Al-Mg-Sc alloy powder
TANG Haozhou, LI Ruidi, ZHU Hongbin, YUAN Tiechui, ZHI Shengxing, YUAN Xiaoxing
DOI: 10.19976/j.cnki.43-1448/TF.2021101
Laser additive repair technologyis of great strategic significance to save cost and improve service performance of materials. In this paper, laser directional energy deposition method was used to study the laser repair of Al-Zn-Mg-Cu aluminum alloy substrate in preset slots. After repairing, the microstructure evolution, metallurgical defects and mechanical properties of Al-Zn-Mg-Cu aluminum alloy were studied by means of scanning electron microscopy, electron backscatter diffraction and universal mechanical testing machine. The results show that the crack is easy to occur when the laser scanning distance increases in repair zone. With the increase of laser energy input, the number of holes in the repair zone increases, and the formation of holes is related to the evaporation of Mg. The Al
3
(Sc,Zr) particles precipitate in the partial melting zone and the boundary of the molten pool in the repaired zone .The Al
3
(Sc,Zr) particles play a role of grain refinement. The grain orientation of the zone between the interior and boundary of repair zone is different obviously. The grain orientation of the repaired zone is random while that of the boundary of repair zoneis consistent. Most of the tensile samples fracture in the substrate region that is thermally cycled by the laser. When the scanning rate is 600 mm/min and the scanning spacing is 0.8 mm, the tensile samples fracture in the repaired zone, and there are a certain number of holes in the fracture of the sample.
2022 Vol. 27 (1): 111-120 [
Abstract
] (
819
)
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(1120 KB) (
1436
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