Xin Liu

Xin Liu
Institute of New Materials, Guangdong Academy of Sciences

Doctor of Philosophy

About

66
Publications
3,421
Reads
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454
Citations
Citations since 2017
59 Research Items
454 Citations
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
Introduction
My current research interest is powder metallurgy, which includes powder preparation, soft magnetic composites, additive manufacturing, and powder metallurgy Ti & rare metals
Additional affiliations
April 2021 - present
Institute of New Materials, Guangdong Academy of Sciences
Position
  • Deputy Director
August 2020 - April 2021
Institute of Materials and Processing, Guangdong Academy of Sciences
Position
  • Deputy Director
August 2019 - August 2020
Guangdong Institute of Materials and Processing, Guangdong Academy of Sciences
Position
  • Deputy Director

Publications

Publications (66)
Article
Low-loss Fe(Si) soft magnetic composites (SMCs) with atomic-layer-deposition coated layer were successfully prepared in this work. The continuous, compact and uniform Al2O3 layer is found to form tight bonding with the powder base. Evolution of the coating layers has been investigated under different annealing temperatures and closely linked to the...
Article
In this study, spherical tantalum (Ta) powders, having different oxygen contents, were fabricated by a radio frequency plasma spheroidization technique. A laser powder bed fusion (LPBF) technique was then used to consolidate these powders and the effects of different LPBF processing parameters on the densification, microstructure and mechanical pro...
Article
Full-text available
Compared to the equiatomic or near-equiatomic NiTinol alloys, Ni-rich NiTi alloys are suitable to be employed in structural applications as they exhibit higher hardness and are dimension�ally stable. This research aimed to process two different grades of Ni-rich NiTi alloys, 58NiTi and 60NiTi, from Ni–Ti powder mixtures having about 58 wt.% and 60...
Article
Here, the FeSiBNbCu/SiO2 soft magnetic composites (SMCs) with core-shell structure were successfully designed and fabricated using nanocrystalline powders as seeds and SiO2 were grown by sol-gel technique onto the surface of the seed particles. We systematically investigated the influences of annealing temperature and compaction pressure on the mic...
Patent
Full-text available
本发明公开了一种镍钛金属间化合物轴承材料及其制备方法与应用,属于粉末冶金技术领域。该方法包括以下步骤:将镍钛混合粉末原料制得的坯体于550‑850℃的条件下预烧结0.5‑8h,再于1035‑1065℃的条件下至少烧结1h。镍钛混合粉末原料中镍粉和钛粉的重量比为59:41‑61:39。通过采用先在特定条件下预烧结再在特定条件下复烧的方式,可避免具有大于50wt.%含量的镍元素的镍钛混合粉末原料直接进行烧结导致液相过度生成,使材料整体塌掉的问题,并且,该方法成本较低、操作容易,适于推广应用。由此得到的镍钛金属间化合物具有较高的组织均匀程度、致密性和硬度,适于制备轴承。
Article
Additive manufacturing exhibits great potentials for the fabrication of novel materials due to its unique non-equilibrium solidification and heating process. In this work, a novel nano-oxides dispersion strengthened Co28Cr9W1.5Si (wt.%) alloy, fabricated by laser powder bed fusion (LPBF), was comprehensively investigated. During the layer-by-layer...
Article
A novel soft magnetic composites (SMCs) was prepared by Fe-6.5 wt%Si/nano-MnZn ferrites composite powders in this work. The nano-MnZn ferrites (~ 20 nm) were synthesized by thermal decomposition method. The microstructure and electromagnetic characteristics of Fe-6.5 wt%Si/nano-MnZn ferrites SMCs were investigated in details. The results showed tha...
Article
Using atomic layer deposition and high-temperature annealing to fabricate coatings for Fe-6.5 wt.%Si powder reduce the hysteresis losses of the resultant composites drastically without sacrificing the permeability properties, and keep the eddy current losses at a relatively low value. The core loss of annealed FeSi SMCs is 39.67% lower than that of...
Article
NiTinol is considered to be an attractive candidate alloy for biomedical applications. The aim of this research was to obtain porous NiTinol parts that respected the general microstructural (having 30–80 vol% interconnected pores and pore sizes in the range of 100–600 μm), compositional (an impurity content of less than 500 ppm) and mechanical (an...
Article
Dual-grain WC/W2C-Cu-Ni composites were fabricated by selective laser melting using a mixture of Ni-coated WC-W2C and CuNi powders. The phase composition and microstructure of the processed composites were investigated by X-ray diffraction, scanning electron microscopy, electron backscattered diffraction and transmission electron microscopy techniq...
Article
The coarsening and inhomogeneous distribution of nano-grains caused by traditional heat treatment processes are the biggest obstacles for obtaining ultrahigh permeability and excellent comprehensive soft magnetic properties in Fe-based nanocrystalline alloys. Here, we propose a new strategy to control grain growth and magnetic anisotropy, by introd...
Article
Fe-Si/MnO-SiO2 soft magnetic composites (SMCs) are prepared by sintering ball milled Fe-Si/MnO2 core–shell structured composites. The correlation between the coating uniformity and electromagnetic properties have been investigated via adjusting ball milling parameters in detail. The results indicate that uniform MnO2 coating can be transformed into...
Article
Fe-based metallic glass has been reported to exhibit high degradation ability for azo dye due to its unique atomic structure. In this work, we show that the degradation efficiency of Fe-based alloy can be further improved via simple heat treatment. Fe82Si2.5B12P2.5C amorphous ribbons were prepared by arc melting and melt spinning and then annealed...
Article
In this paper, silicone-resin coating Fe-Si soft magnetic composites (SMCs) with high magnetic permeability, low core losses and good temperature/frequency stability were successfully fabricated. Microstructural characterizations suggest that the thin, continuous and heat-resistant silicone-resin coatings are constructed surrounding magnetic partic...
Article
This research aimed to process 60NiTi with a dense and homogeneous microstructure from a Ni–Ti powder mixture. It was noted that the optimum route, amongst the ones studied in this research, for obtaining parts having a homogeneous microstructure and the highest amount of relative density is as follows: The powder mixture being initially CIPed was...
Article
Fe-Si soft magnetic composites (SMCs) coated with MnO-SiO2 composite coatings were fabricated via sintering the ball milled Fe-Si/MnO2 composite powders. The transformation mechanism from MnO2 coating to MnO-SiO2 composite coatings was studied. The effect of MnO2 content on the microstructure and magnetic properties of Fe-Si soft magnetic composite...
Article
58Ni39Ti-3Hf alloy system has been proposed as an alternative for superelastic 60NiTi used in load-bearing applications. This research was focused on the development of heat treatment procedures leading to 58Ni39Ti-3Hf parts with maximum possible hardness values. Meanwhile, the relations existing between the heat treatment – microstructure – hardne...
Article
In this study, spherical Ni-Ti composite powder was synthesized from blended elemental Ni and Ti powders using radio frequency plasma spheroidization process. The effects of powder feeding rate and carrier gas flow rate on the spheroidization efficiency and Ni content of the obtained powders were investigated. The spherical Ni-Ti composite powder w...
Article
Insufficient amorphous forming ability (AFA) and thermal instability have always been the bottleneck restricting the application of high Fe content iron-based nanocrystalline soft magnetic materials. In this work, the effects of micro-compressive stress annealing (MCSA) on microstructure, soft magnetic and mechanical properties of high Fe content F...
Patent
摘要 本发明提供了一种镍钛合金材料的制备方法,包括以下步骤:(1)将镍钛合金材料置于密闭容器中在900~1050℃和150~180MPa下保温保压不少于4小时;所述镍钛合金材料以镍和钛元素混合粉末为原料经选区激光熔化制备,所述镍和钛元素混合粉末中的镍含量为50at.%~55at.%;(2)将步骤(1)处理后的镍钛合金材料置于密闭容器中在1120~1140℃和180~200MPa下保温保压不少于1小时;自然冷却得到所述选区激光熔化制备镍钛合金材料。本发明的制备方法针对镍含量在50at.%~55at.%的镍钛合金材料,将经过选区激光熔化制备的镍钛合金材料进行两个阶段的高温高压处理,并且限定高温高压处理的温度和压力,消除了经过选区激光熔化制备的镍钛合金材料中的残余单质相、孔隙和微裂纹,提升了产品质...
Article
The effects of Co on microstructure, crystallization behavior and magnetic properties of (Ni0.5Fe0.5-xCox)80B10Si2Cu1Zr7 (x = 0~0.5) alloys were investigated. The results show that, the as-spun alloys remain lower coercivity (Hc) values (5 A/m ~ 14 A/m) over the whole Co content range, owing to their amorphous structure. After being annealed for 20...
Article
Equiatomic and near-equiatomic NiTinol alloys, mainly due to the exhibition of adjustable mechanical and thermal shape memory properties, are widely exploited to produce different smart and functional devices. Laser powder bed fusion technique was used in this research to process dense NiTinol parts from a prealloyed near-equiatomic NiTi powder, us...
Article
Full-text available
Fe−6.5Si soft magnetic composites (SMCs) with hybrid phosphate-silica insulation coatings have been designed to improve their comprehensive property via chemical coating combining sol-gel method in this work. The microstructure and magnetic performance of the Fe−6.5Si SMCs with hybrid phosphate-silica insulation coatings were investigated. The hybr...
Article
To obtain spherical cemented carbide powders suitable for the additive manufacturing process, granulated WC-Co powders made by spray drying were spheroidized by radio frequency inductively coupled plasma. The influence of powder feed rate on the sphericity of the obtained powders was investigated. Results show that spheroidization efficiency of nea...
Article
17-4PH stainless steel parts, fabricated by selective laser melting, were subjected to the solution and aging treatments conducted under vacuum and hot isostatic pressing (HIP) conditions. The microstructure of as-built and heat-treated specimens were characterized using X-ray diffraction, scanning electron microscopy and transmission electron micr...
Article
Full-text available
In this study, spherical tantalum powder fabricated by radio frequency plasma spheroidization system was used for selective laser melting densification. Through optimizing the processing parameters, the fully dense Ta sample was obtained at the scanning speed of 650 mm/s and the laser power of 240 W. Attributed to the high sphericity, the Ta sample...
Article
In this paper, Fe-6.5 wt%Si powders were oxidized with different temperatures, and Fe-Si soft magnetic composites with Fe2SiO4 coating layer were transformed successfully by high temperature solid state reaction sintering between the surface oxides and Si element in Fe-6.5 wt%Si powders. The influence of the oxidation temperature on the microstruct...
Article
Effects of the minor addition of similar ferromagnetic elements (Fe, Co, Ni, and Gd), metal element with strong non-metallic properties (Al), and transition metal elements with large atomic radius (V, Hf, Ti, and Cr) on crystallization behavior, magnetic properties and bending ductility of Fe 85 Si 0$5 B 9 P 4 Cu 0$5 C 0.1 M 0.9 alloys were systema...
Article
This paper aimed at improving high-frequency magnetic properties and decreasing material cost of “Finemet”alloy without sacrificing saturation magnetization (Ms) and coercivity (Hc) by minor V and Mo substitution of Nb. Both V and Mo enhanced glass forming ability (GFA) and promoted the precipitation of primary α-Fe particles. Meanwhile, V addition...
Article
Full-text available
Ni-rich Ni-Ti alloys, such as 60NiTi, show a higher hardness and dimensional stability than equiatomic or near-equiatomic NiTinol ones. These make them suitable to be employed in structural applications. Laser powder bed fusion technique (LPBF) was used in this research to print parts from a Ni-rich Ni-Ti powder mixture consisting of about 63 wt.%...
Article
Co–Cr based alloys are recognized as one of the most widely used category of alloys amongst the biomedical materials. This is because these alloys show a high strength, corrosion resistance and good biocompatibility suitable for biomedical applications. Many researchers have been focused on the processing of these alloys using a selective laser mel...
Article
A new one-pot highly efficient synthesis method implemented using an industry-oriented roboticized coating device was designed and developed for obtaining high quality SiO2-coating on the surface of commercial Fe78Si13B9 (FeSiB) amorphous flaky powder at the room temperature. Hereinto, the conventional instilling method was modified as directly pou...
Article
The effect of Fe nanoparticles with mass fraction of 0-7 wt% on the microstructure and soft magnetic properties of the Fe-6.5 wt%Si soft magnetic composites (SMCs) was investigated. The results show that the pores between Fe-6.5 wt%Si powders can be effectively filled by Fe nanoparticles, thereby correspondingly increasing the density of the SMCs....
Article
Titanium hydride powder was used to completely or partly replace the spherical titanium powder in order to reduce the cost. The microstructure and mechanical properties after debinding and sintering were investigated. The results showed that with the addition of the titanium hydride powder, the microstructure gradually changed. The fabricated alloy...
Article
Co element was doped in Fe-6.5Si alloy and the corresponding soft magnetic composites were fabricated successfully by conventional powder metallurgy techniques in this work. Saturation magnetization of Co-doped Fe-6.5Si powder increases compared to powders without Co and the coercivity increases because of grain refinement. Co addition is helpful t...
Article
In this work, Fe2SiO4/SiO2 coated Fe-Si soft magnetic composites (SMCs) have been prepared successfully via ball milling Fe-6.5wt%Si/Fe3O4 composite particles combined with subsequent spark plasma sintering (SPS) process. The formation mechanism of Fe2SiO4/SiO2 insulating layer and effect of Fe3O4 coating content on the microstructure and propertie...
Article
Full-text available
In this present work, Nickel-coated tungsten carbide powder was prepared by high concentration electroless nickel plating without noble metal catalysis and the WC/W2C based composites were successfully prepared by Selective laser melting (SLM). The Ni layers covering on tungsten carbide particles were controlled by the reagent type of complexing ag...
Article
In this paper, a novel core–shell structured [email protected]/Al2O3 soft magnetic composites (SMCs) has been fabricated by the combination of ball milling with MnO2 and spark plasma sintering (SPS) process. The structure and phase evolution of MnO/Al2O3 insulation layer also were investigated. Meanwhile, the influences of various MnO2 content on m...
Article
In this study, effects of Mo and V substitution for Fe on a direct aim of synchronously optimizing glass forming ability (GFA) and soft magnetic properties of Fe-based amorphous/nanocrystalline alloys fabricated by melt-spinning technology are investigated. The introduces of Mo and V had an effective impedance of atoms migration and contributed to...
Article
Fe-Si soft magnetic composites (SMCs) coated with novel insulating-magnetic-insulating (IMI) layer were prepared via ball milling Fe-Si/γ-Fe2O3 powders and subsequent spark plasma sintering (SPS) process. We had investigated the formation mechanism of the IMI layer and optimized the microstructure and magnetic properties of the Fe-Si/IMI SMCs by ad...
Article
In this work, Fe–Si/Fe2SiO4 soft magnetic composites (SMCs) are prepared successfully via sintering Fe-6.5 wt%Si/α-Fe2O3 core-shell composite powders obtained by ball milling. The transformation mechanism from Fe-6.5 wt%Si/α-Fe2O3 to Fe–Si/Fe2SiO4 is revealed in detail. The effect of α-Fe2O3 coating content on microstructure and magnetic properties...
Article
Fe1.82Si0.18@Al2O3 soft magnetic composites (SMCs) have been fabricated by NaOH oxidation combined with subsequent spark plasma sintering (SPS). The microstructure and generation mechanism of Fe3O4 coatings on the surface of FeSiAl powders have been investigated systematically. Effects of oxidation time on the magnetic properties also have been rev...
Article
Fe-Si SMCs with different insulating layer (Fe2SiO4/SiO2) have been prepared successfully via sintering the oxidized Fe-Si powders at different temperature. We have investigated the effect of sintering temperature on microstructure and magnetic properties for the Fe-Si SMCs in detail. The insulating layer is mainly Fe2SiO4 when the sintering temper...
Article
Polycrystalline diamond compact (PDC) bit matrix materials were fabricated by pressureless infiltration method using the cast tungsten carbide powders mixed with nickel powders as the skeleton powders. The effects of the morphologies, particle sizes and content of the cast tungsten carbide powders on the microstructure and mechanical properties of...
Article
FeSiAl/Fe 3 O 4 core-shell composite particles and transformed Fe 3 Si/Al 2 O 3 composite compacts have been prepared via ball milling coating combined with subsequent spark plasma sintering (SPS) process. The formation mechanism of the Al 2 O 3 insulating layer and the magnetic properties of the Fe 3 Si/Al 2 O 3 composite compacts have been invest...
Article
In this paper, Ti600 alloy was successfully prepared by elemental powder metallurgy method followed by subsequent hot extrusion (950 °C, extrusion ratio of 9:1) and vacuum annealing. The microstructure and mechanical properties were systematically investigated. The as-sintered alloy presented Widmanstatten microstructure and large amount of pores....
Article
Ti600 alloy (with a nominal composition of Ti-6Al-2.8Sn-4Zr-0.5Mo-0.4Si-0.1Y) was prepared by cold isostatic pressing and vacuum sintering using the mixed element powder method. The effects of sintering temperature on the microstructure, density and mechanical properties of the alloy were investigated. The results show that the microstructure of Ti...
Article
The effects of the amount of Fe-6.5%Si powder on the magnetic properties of the composite magnetic powder cores successfully prepared by mixing Fe-6.5% Si powder to Fe73.5Cu1Nb3Si13.5B9 nanocrystalline powder were discussed. The results showed that with the amount of Fe-6.5%Si powder increasing from 20% to 80%, the density of composite magnetic pow...
Article
In this study, the intergranular insulating Fe-6.5wt.%Si/SiO2 soft magnetic composites (SMCs) were prepared successfully using in-situ chemical deposition followed by the spark plasma sintering (SPS) process. The effects of ammonia concentration on the microstructure and magnetic properties of the composites have been studied systematically. The Fe...
Article
The intergranular insulating Fe-Si soft magnetic composites (SMCs) with uniform three-shell SiO2-Fe2SiO4-SiO2 insulating layer were prepared successfully via simple water oxidation combined with the spark plasma sintering process (SPS). The formation mechanism of the insulating layer and the magnetic properties of the Fe-Si SMCs have been studied s...
Article
xTi/Fe-3Si-0.5Al-2Ni (x=0, 1, 2) soft magnetic composites were prepared by gas atomization and compression molding. The phase structures, morphologies and magnetic properties of the both powders and Ti/Fe-3Si-0.5Al-2Ni soft magnetic composites were analyzed by XRD, SEM, physical property measurement system (PPMS) and soft magnetic alternating curre...
Article
A novel Ti-doped Fe-6.5Si soft magnetic composites (SMCs) was prepared in this work. Effects of doping Ti on magnetic performances of Fe-6.5Si SMCs were investigated. The results show that only α-Fe(Si,Ti) phase can be detected in Ti-doped Fe-6.5Si particles and SMCs. After doping Ti the saturation magnetization of Fe-6.5Si powders significantly re...
Chapter
Full-text available
High quality Ti–6Al–4V alloy powders were prepared by plasma rotating electrode process (PREP). Three different rotating speed were selected. After sieved, three kinds of powder with different size distribution were consolidated by hot isostatic pressing (HIP). The phase compositions, morphologies and microstructures of the powders and HIPed sample...
Article
Full-text available
The objective of this paper is to improve the performance of high temperature titanium alloys with a high Si content by powder metallurgy. Firstly Ti-6.5Al-1.4Si-2Zr-0.5Mo-2Sn alloy powders were prepared using two different rotating speeds by plasma rotating electrode process (PREP). Then two sintering temperatures were selected to fabricate titani...
Article
This research aims to prepare high quality powder of Ti-6.5Al-1.4Si-2Zr-0.5Mo-2Sn, which lays foundation for the following preparation of powder high temperature titanium alloy component.Ti-6.5Al-1.4Si-2Zr-0.5Mo-2Sn alloy ingots were prepared by vacuum arc remelting (VAR). The chemical compositions of ingots were examined. The loss of alloy element...
Article
Full-text available
In order to ensure high wear resistance of parts and tools, operating at significant dynamic loads in the extreme conditions, the layers different in their function purpose obtained using surfacing methods are widely used. In such surfacing compositions, the powders of high-melting compounds characterized by high hardness and strength, are used as...
Article
Full-text available
Tungsten carbide powders with different particle sizes were prepared by different methods, and then they were added into Fe alloy powders. The laser cladding technique was used to form an alloyed layer with high hardness and wear resistance on 45# steel with such mixed powders to study the effects of cast tungsten carbide powders on wear resistance...
Article
The microstructure and magnetic properties of Fe-6.5% Si phosphate powder and powder cores were analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), physical property measurement system (PPMS) and soft magnetic alternating current measuremen...
Article
Four kinds of spherical Ti-6Al-4V powders prepared by PREP method were vacuum hot pressed. The phase composition, microstructure, fracture morphology and mechanical properties of sintered samples were investigated by XRD, SEM and mechanical tests respectively. The effects of the particle size on microstructures and mechanical properties of Ti-6Al-4...
Article
Fe-3%Si-2%Ni-0.5%Al-1%Ti soft magnetic alloy powders were prepared by inert-gas atomization. The composition, size distribution, and surface morphology of the powder were characterized by chemical analysis, laser scattering particle size distribution analyzer and electron probe microanalyzer, respectively. The effects of atomization pressure, tempe...
Conference Paper
Fe100-xCox-6.5wt%Si (x=0, 1, 3, 5, 7, 10, 15, 35, 50) magnetic powder cores (MPCs) were prepared by gas atomization,insulation, compression molding, and heat treatment. The effects of Co element on microstructure and magnetic properties of the Fe-6.5wt%Si MPCs were investigated. The results showed that the addition of Co element doesn’t change the...
Article
Fe-3Si-2Ni-0.5Al-2Ti magnetic powder cores were prepared by gas atomization and compression molding. The thermal stability of insulation binder, phase composition, carbon and oxygen content, magnetic properties of magnetic powder cores were analyzed by thermal analyzer, X-ray diffractometer, electron probe microanalyzer, and soft magnetic alternati...
Conference Paper
Full-text available
Fe-3%Si-0.5%Al-2%Ni-2%Ti soft magnetic alloy powders were prepared by inert-gas atomization. The composition, phase structure, size distribution, surface morphology and cross-sectional microstructure of the powder were characterized by chemical analysis, X-ray diffractormeter, laser scattering particle size distribution analyzer and electron probe...
Conference Paper
TiNi gas-atomized powders and TiNi coating fabricated by low temperature high velocity oxygen fuel (LT-HVOF) spraying were characterized. The results showed that the Ni-rich Ti-51. 25at. %Ni powders were obtained by gas atomization. The particle size of most TiNi powders ranges from 16. 58 to 68. 86 μm, with a median size of 39. 87 μm in diameter....

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Projects (4)
Archived project
60NiTi is recently introduced as a material having potential to be employed in load bearing applications. However, the current method used to process this material is costly making this alloy 3 to 4 times more expensive than hard steels used in bearing applications. This project aimed to develop novel cost-effective powder metallurgy processing routes to manufacture hard Ni-rich NiTinol alloys (e.g 60NiTi) using blended Ni and Ti powders. In this project, cost-effective powder metallurgy and additive manufacturing processing routes and post-processing treatments to manufacture dense Ni-rich Ni-Ti alloys from elementally mixed Ni-Ti powders were developed.
Project
To prepare the metal powders for additive manufacturing and investigate the effects of powder characteristics on additive manufacturing.
Project
To prepare the SMCs and improve the magnetic properties of the SMCs.