Chao Chen

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Verified

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• Doctor of Engineering
• Researcher at Jilin University

Nowadays, how to achieve high strength welding of 7xxx aluminum alloy has attracted much attention. In this article, the melt inert gas (MIG) welding test of aluminum alloy 7075 (AA7075) is carried out by using the self‐developed welding wire of Al‐Zn‐Mg‐Cu‐0.7 TiC nanoparticles (NPs). The microstructure and mechanical properties of nanoparticle‐en...

Reasonably controlling heat input is crucial for optimizing the weld quality of Mg alloys with thermal sensitivity. But it falls to meet diverse requirements of industrial welded structures. This study synchronously adjusts welding current, voltage and speed with constant heat input to achieve further regulation on weld quality of Mg alloy thin pla...

The coarse grain size and shallow weld penetration in welded joints have always been a challenge for titanium alloy TIG welding. To solve this problem, this work investigates the influence of ultrasonic coaxial assisted TIG (U-TIG) method on the formation, microstructure, and mechanical properties of TC4 titanium alloy weld seams by controlling ult...

(FeCoNi)96Al4 high-entropy alloy (HEA) is a new material with a strength similar to that of commercial Q235 structural steel, and its elongation is nearly three times greater than that of Q235 steel. Studying the welding process of the (FeCoNi)96Al4 HEA and Q235 steel is expected to further expand the application range of commercial Q235 structural...

To explore the effects of laser processing variables on the macroscopic appearance, microstructural makeup, and functional properties of high-entropy alloy (HEA) coatings, CoCrFeNiMn coatings were deposited onto the surface of Q235 steel via laser cladding, with adjustments made to parameters like laser power and scanning speed. The research findin...

There is a great deal of interest in improving the efficiency of arc-directed energy deposition (Arc-DED) of aluminium matrix composites and the uniform introduction of reinforcing particles. In this work, ceramic/aluminum-titanium gradient composites were manufactured by hybrid additive manufacturing with arc and laser cladding eutectic pools. The...

In this paper, a new waveform of AC/DC mixed waveform (MIX) is proposed to weld CMT-WAAM-AZ31B magnesium alloy components. CMT-WAAM-AZ31B magnesium alloy welded joints were prepared by AC-TIG and MIX-TIG. Welding parameters are scanning speed 3mm/s, current 180A, voltage 16V. The results show that the dendrites in the MIX weld are transformed into...

In this study, the first attempt to deposit two dissimilar alloys using different additive manufacturing techniques for obtaining the superior performance composite part. AISI 410 martensitic steel part was obtained by wire-arc directed energy deposition (wire-arc DED) firstly, then CoCrFeNiMo HEA powders were deposited on 410 martensitic part usin...

In this study, the effects of ultrasonic coaxial assisted TIG welding (U-TIG) on the formation, microstructure, and mechanical properties of TC4 titanium alloy welded joints were investigated. The results indicated that at optimal ultrasonic power and welding current settings, remarkable improvements of welded joint were observed. Specifically, the...

Direct current (DC) and pulsed DC tungsten inert gas (TIG) additive manufacturing processes were employed to fabricate GH4169 high-temperature alloy specimens. Upon comparing and analysing the two additive manufacturing methods, the evolution of microstructure and mechanical properties of the additively manufactured specimens were discussed. It pro...

The existing methods for preparing titanium matrix composites (TMCs) are less efficient and more expensive. An interlayer laser cladding SiC during arc-directed energy deposition Ti-6Al-4V was developed to efficiently prepare the TMCs, whose microstructure and mechanical properties were analysed to explore the mechanism for change. TiC and Ti5Si3 p...

High-entropy alloys (HEAs) are newly developed materials that have many excellent properties, such as a high strength-to-weight ratio and excellent tensile properties. If high-entropy alloys and stainless steel are joined by welding, the advantages of their properties can be balanced. In this paper, dissimilar lap joining of Al 0.3 CoCr-FeNi-HEA wi...

The direct preparation of large components by laser cladding (LC) is not economical, but if it is used as a means of trace element addition and combined with the high efficiency advantages of wire arc additive manufacturing (WAAM), efficient manufacturing and high degree of freedom design of components can be achieved. In this study, high toughness...

To fully exploit the advantages of steel, the welding connection of dissimilar steels has been developed. In this work, the metallographic microstructures, elemental distributions, and electrochemical corrosion properties of the Q235 and 304 welds under different bias arcs were investigated. The arc bias caused the Q235-side heat-affected zone to w...

MIG welding still had a lot of potential in the titanium alloy industry with many advantages. How to achieve stable process and forming was still a hard nut to crack for titanium alloy MIG welding. The conventional MIG welding torch had a small coverage of shielding gas which causes an obvious insufficient capability of isolating air. Therefore, th...

In this work, CrMnFeCoNi high-entropy alloy coating was successfully prepared on the surface of aluminum alloy by laser cladding. The relationship between the geometrical morphology of the coating cross section and laser process parameters was systematically studied. The influence of line energy and the number of remelting on the morphology of the...

In this paper, the bypass microhole high-density airflow (BMHA) was innovatively introduced into the welding of 4047 Al alloy for enhancing weld quality. The arc morphology, macrostructure, microstructure and tensile behavior of the weld were investigated. After applying the bypass airflow, the arc gradually transformed from a bell shape into a lon...

Coarse β-grains and severe surface oxidation are major factors plaguing the comprehensive properties of tungsten inert gas (TIG) welded joints of titanium alloy. To improve the performance of welded joints, a novel current waveform, alternating current/direct current (AC/DC) mixed current waveform which was named Mix-TIG was proposed. In Mix-TIG, t...

GTAW has less arc energy density and coarse joint microstructure. A novel method of Ultrasonic-Magnetic field coaxial hybrid GTAW (U-M-GTAW) was proposed, which improved upon the traditional GTAW torch. Under 140 A current and 4 mm/s speed, the results indicated that the U-M-GTAW depth-to-width ratio increased by 54.5 % compared to GTAW. Meanwhile,...

To reduce the impact of heat accumulation during additive manufacturing, this study used the dual-pulse GMAW-AM (Gas Metal Arc Welding-Additive Manufacturing) method for the preparation of aluminum silicon alloy components, and an interlayer rapid cooling device was designed for additive manufacturing. The results showed that the proportion of smal...

In this study, the GMAW welding torch was controlled by a stepping motor to achieve a periodic swing. By controlling the swing speed, a micro-variable deposition path was obtained, which was called the micro-control deposition trajectory. The influence of the micro-control deposition trajectory on the arc characteristics, microstructure, and mechan...

An innovative wire arc additive repair approach based on the extreme low heat input was proposed to repair the defect of Ti-6Al-4 V in this study. Arc was ignited between the tungsten electrode and hydrocooling Cu pipe over the substrate, avoiding arc acting on the substrate directly and resulting in a smaller heat affected zone (HAZ) and finer gra...

The geometric parameters of the deposited layer include the width, height, and penetration depth of the deposited layer. The welding current, wire feeding speed, and torch travel speed during the additive manufacturing process of TC4 titanium alloy have the greatest impact on the geometric parameters of the deposited layer. In order to study how th...

Double-pulsed gas metal arc welding (DP-GMAW) is a high-performance welding method with low porosity and high frequency. Periodic shrinkage and expansion of the melt pool during DP-GMAW leads to unusual remelting, and the re-solidification behavior of the weld metal can significantly refine the weld structure. The advantages of DP-GMAW have been pr...

This paper aims to enhance the efficiency of the utilization of arc energy by adding ultrasonic and magnetic fields. A new welding method is proposed and named as ultrasonic-magnetic coaxial hybrid gas tungsten arc welding (U-M-GTAW). In this paper, the effect of tungsten extension and welding current on the arc characteristics under different weld...

A new method of Ultrasonic-Magnetic field coaxial hybrid GTAW (U-M-GTAW) was proposed in this paper to improve the joints properties by coaxially coupling ultrasonic vibration and magnetic field to the welding arc. The microstructure and mechanical properties of 304 stainless steel in the welded joints of GTAW, Ultrasonic-GTAW (U-GTAW), Magnetic fi...

In this work, a new welding method, AC-DC hybrid TIG welding, is used to weld 304 stainless steel. Research on the formation, microstructure, and properties of 304 stainless-steel welded joints are studied by using optical microscope and microhardness. The results show that the weld with AC/DC hybrid welding is a fish-scale pattern, and the density...

The novel AZ31B/SiCps composite was prepared by wire-arc directed energy deposition (DED-Arc) method. The effects of SiCps content in the range of 1.0–3.0 wt% on grain orientation, average grain size, grain boundary angle distribution, and mechanical properties of AZ31B magnesium alloy were studied. The results showed that SiCps, as a reinforcing p...

In this work, a new current waveform, the AC/DC mix current waveform was employed to improve the microstructure and mechanical properties of 307Si stainless steel component during the TIG based wire arc additive manufacturing (TIG-WAAM). The results showed that the morphology of γ-austenite is changed from the columnar dendrites (with DC mode) to t...

In this work, the thin wall components of TC4 titanium alloy were produced by using external magnetic field hybrid gas metal welding (EM-GMAW). The effect of the external magnetic field on the forming, microstructure, and property of wire arc additively manufactured TC4 titanium alloy was studied in detail. The results showed that the height of the...

Available online xxxx Keywords: 2A12 aluminum alloy High frequency impacting and rolling Microstructure Corrosion behavior a b s t r a c t This paper investigated the influence of high frequency impacting and rooling (HFIR) treatment on the microstructure, average microstrain, dislocation density, nanomicrohardness, tensile strength and corrosion b...

In this work, AZ31B magnesium alloy is welded using an AC/DC mixed gas tungsten arc welding (MIX-GTAW) process. The effect of the AC ratio on the microstructure and mechanical properties of AZ31B magnesium alloy MIX-TIG welded joints was investigated. The AC ratio range tested was 0 %-100 %. The surfaces of the welds formed at different AC ratios a...

Laser cladding technology is usually employed to produce high-entropy alloy coatings. However, the thickness of coatings is normally up to a millimeter scale, which increased the consumption of laser energy and materials. In this work, a micron-scale coating of CrMnFeCoNi high-entropy alloy on Al alloy by using low-power laser cladding was proposed...

Cold metal transfer (CMT) welding is an attractive welding technology for thin sheet aluminum alloys because of its low heat input, arc stability and spatter-free behavior during the welding process. The present research is mainly concerned with the effect of different heat input on microstructure and mechanical properties of CMT welding 2A14 alumi...

A wire arc additive manufacturing hybrid interlay er high speed friction (WAAM-HSF) approach is proposed to improve the performance of wire arc additive manufacturing (WAAM) components. The effect of WAAM and WAAM HSF on the microstructure and mechanical properties of thin walled aluminium alloy components was investigated using 1.2 mm diameter 404...

Ultrasonic-magnetic field coaxial hybrid GTAW(U-M-GTAW) is a new non-melting electrode welding method proposed by combining ultrasonic assisted GTAW(U-GTAW) and magnetic assisted GTAW(M-GTAW) on the regulation characteristics of the GTAW arc. U-M-GTAW introduces ultrasonic and magnetic field effects into GTAW to improve arc characteristics. The ort...

Heat input is a critical parameter in wire arc additive manufacturing (WAAM). A large number of studies have been carried out on the heat input of WAAM. However, the current research only focuses on the influence of different heat input values on the structure and performance of components, and the influence of equivalent heat input on the structur...

In order to achieve high-quality welding of aluminum alloys, reasonable control of welding heat input is critical. Different combinations of welding parameters can achieve the same heat input, however, the relevant research results has not been reported. In this paper, the pulsed-gas metal arc welding (P-GMAW) of 4047 Al-Si alloy was used as the re...

In this work, based on the effect law of standing wave ultrasonic and axial magnetic field on the GTAW, a novel method of GTAW is proposed by coaxial hybrid standing wave ultrasonic and axial magnetic field, which is named as the ultrasonic and magnetic field coaxial assisted GTAW (U-M-GTAW). This paper focuses on the validation of the feasibility...

A method of wire arc additive manufacturing hybrid interlayer high-speed friction (WAAM-HSF) was proposed. Microstructure and mechanical characteristics of 307Si stainless steel in the WAAM and WAAM-HSF were investigated. The microstructure in the WAAM and WAAM-HSF consisted of γ-austenite and residual δ-ferrite. The microstructure in the WAAM-HSF...

Ultrasound-magnetic field coaxial hybrid Gas Tungsten Arc Welding (U-M-GTAW) is proposed to control the arc characteristics. Arc characteristics and its changing mechanism in ultrasound - magnetic field coaxial hybrid GTAW were studied by experimental and theoretical analyses. The results showed that the periodic rotation and compression of arc sha...

The purpose of the method of AC/DC mixed gas tungsten arc welding (GTAW) is to improve the welding efficiency of aluminum alloy AC-GTAW. It is expected to make a great change in the aluminum alloy manufacturing industries. The feature of AC/DC mixed GTAW includes two parts, AC mode and DC mode, during the welding process. A comparison study between...

Abstract: In this work, a new welding electrical signal waveform of the AC/DC mixed waveform is purposed to improve the welding quality of magnesium alloy TIG. The method is named as AC/DC mixed tungsten inert gas arc (MIX-TIG) welding. The AZ31B Mg alloy welded joints were obtained by AC-TIG and MIX-TIG. Through investigation of the weld formation...

Available online xxxx Keywords: CMT double side welding 2A12 aluminum alloy Microstructure Mechanical properties a b s t r a c t In this work, the cold metal transfer (CMT) double side welding was carried out to weld 2A12 aluminum alloy plate. The influence of the heat input on the weld appearance was studied, which indicated that when the heat inp...

Additive manufacturing of Al-Si alloy thin-walled components with/without interlayer adding La 2 O 3 powder were obtained by cold metal transfer (CMT). Based on the optimisation of the CMT additive manufacturing process, the influences of La 2 O 3 powder on the microstructure and properties of parts were analysed by using OM, SEM and EBSD. The resu...

Compared with the gas metal arc welding (GMAW), the cold metal transfer technology can significantly reduce the welding heat input owing to obtain the output current of almost zero in the droplet detaching, which has a greater advantage in additive manufacturing. In this work, the cold metal transfer was employed to study the law of appearance and...

Gas tungsten arc (GTA) cladding has the advantages of flexibility, low cost, and high quality. AlCoCrFexNi (x = 1.0, 1.4, 2.1, 3.0, denoted as S-150, S-160, S-170, S-180, respectively) HEA coatings are prepared by GTA cladding on a low carbon steel substrate using different specific heat input (cladding current). The microstructure and phase struct...

This paper investigated the effect of pulsed power ultrasonic on the appearance, microstructure and mechanical properties of aluminum alloy using self-developed pulsed power ultrasonic wave assisted gas metal arc welding (PU-GMAW) device. The feature of the method was to combine arc and pulsed power ultrasonic field coaxially. The results indicated...

Arc plasma shape under pulsed and continuous ultrasound field was studied in this research using a self-developed welding device which combines arc and ultrasound field coaxially. The results show that, compared with the arc of conventional tungsten inert gas welding, the shape of arc under pulsed power ultrasound field relates to the pulse frequen...

Wire arc additive manufacturing (WAAM) of AlSi alloy deposits exhibits the advantages of a high deposition rate and easy operability, while being suitable for fabricating large-sized metal parts. However, the alloy deposits suffer from various problems such as a large number of pores, coarse and uneven microstructures, and poor mechanical propertie...

7A52 aluminum alloys were treated by ultrasonic shot peening (USSP) technology. Then, friction and wear behavior of 7A52 aluminum alloys was obtained by a ball-on-disk friction and wear test. The surface grains of the 7A52 aluminum alloys were refined into nanocrystals with an average size of about 23 nm, and a severe plastic deformation zone with...

High-entropy alloys (HEA) are promising coating and structural materials for their excellent mechanical and corrosion properties, but the problems like coarse grain hinder the application. Ultrasonic treatment generally has the effect of grain refinement. Therefore, ultrasonic treatment is introduced to the process of gas tungsten arc (GTA) claddin...

The excellent mechanical and corrosion properties make high-entropy alloys (HEA) be promising structural and coating materials. However, problems like element segregation hinder the fabrication and application of HEA. Ultrasonic melt treatment (USMT) generally has the effect of segregation suppression. In the present study, the impact of ultrasonic...

Arc cladding high-entropy alloy (HEA) coatings have the advantages of low cost and flexibility. It exhibits economic value to increase the proportion of Fe element in HEA systems. As a result, low-cost AlCoCrFeNi (Fe content of 42.5 at.%, 44.9 at.%, 47.5 at.%, 50.4 at.%) HEA coatings are prepared by gas tungsten arc (GTA) cladding and their microst...

The columnar to equiaxed transition (CET) of grain structures has been a great challenge during titanium alloy additive manufacturing (AM), especially for wire arc additive manufacturing (WAAM) with the highly localized heat input and large temperature gradient. In this work, three combined methods (ultrahigh frequency pulse arc + growth restrictin...

High nitrogen stainless steel has extensive applied foreground in industries. But the weldability limits the use of the steel. The weld without nitrogen can become the weakness of the joint in corrosion resistance and strength. In this study, response surface methodology was applied to optimize the Ar-N2-CO2 ternary shielding gas for a nitrogen-con...

Wire arc additive manufacture (WAAM) technology was employed to repair Ti–5Al–2Sn–2Zr–4Mo–4Cr (TC17) titanium alloy, which is widely used as compressor blades and blisk. The microstructure evolution and mechanical properties of the repaired specimen were investigated. The results show that the repaired specimen has a good verticality, and it forms...

Three nitrogen-rich welding wires with nitrogen content of 0.15 %, 0.6 % and 0.9 % for high nitrogen stainless steel welding were developed by a modified Schaeffler diagram and equilibrium phase diagram calculation. The effect of the chemical compositions especially the nitrogen on the weld defects, element distribution, microstructure, mechanical...

The effect of welding current, welding arc length and gas flow rate on holographic interference fringe wasinvestigatedG During holographic interference test, the reasonable range of the welding parameters is presented, and the calculation of the holographic interferometric arc temperature field is enumerated. the results shown that when the welding...

Pulsed ultrasonic-assisted gas metal arc welding (PU-GMAW) is a newly developed welding method. Pulsed frequency is one of the most important parameters in the PU-GMAW process. In this paper, the influence of pulsed frequency on the GMAW of aluminum alloy was studied. The results showed that the conventional GMAW process was improved significantly...

In this paper, TC11-TC17 dual alloy specimens were fabricated by wire and arc additive manufacturing (WAAM) technique with wrought TC17 as the substrate, TC11 wire as the feedstock. Annealing treatments were performed at 560 °C,700 °C and 800 °C in vacuum for 2 h followed by air cooling in order to optimize the microstructure and mechanical propert...

In the paper, La2O3 with two different mass fractions was alloyed with Ti-6.5Al-3.5Mo-1.5Zr-0.3Si by wire and arc additive manufacturing technique. The effect of La2O3 addition on the microstructure evolution and mechanical performance was investigated. The results show that the La2O3 addition can significantly refine the size of prior β grains. Th...

The pulsed power ultrasonic-assisted gas metal arc welding (PU-GMAW) is a new development hybrid welding method. The influences of the pulsed power ultrasonic on the microstructure evolution of the welded joint of Al–Cu alloy were investigated by using scanning electron microscopy, transmission electron microscope and electron back scattering diffr...

The pulsed power ultrasonic-assisted gas metal arc welding (PU-GMAW) is a new development hybrid welding method. The influences of the pulsed power ultrasonic on the microstructure evolution of the welded joint of Al-Cu alloy were investigated by using scanning electron microscopy (SEM), transmission electron microscope (TEM) and electron back scat...

The quality of welded joints is affected by microstructure heterogeneity of the weld seam. In this work, the microstructure homogenization of 2A14 aluminum alloy weld seam was achieved by adding ultrasonic irradiation in the metal-inert gas welding (U-MIG). Compared with the traditional MIG, the width and penetration of the weld seam in the U-MIG i...

High nitrogen stainless steel with nitrogen content of 0.75% was welded by gas metal arc welding with Ar-N2-O2 ternary shielding gas. The effect of the ternary shielding gas on the retention and improvement of nitrogen content in the weld was identified. Surfacing test was conducted first to compare the ability of O2 and CO2 in prompting nitrogen d...

The nitrides were added to the molten pool to optimize the microstructure and mechanical properties of high nitrogen stainless steel weld. The nitrides of the alloy element that promote the nitrogen dissolution were selected. The alloy element and nitrogen element were thereby simultaneously added to the weld. MnN was selected from TiN, VN, CrN and...

The formation and microstructure of TC4 weld bead was investigated by using pulse ultrasound assisted TIG welding (PU-TIG). The results showed that weld penetration and weld width in the PU-TIG were increased by around 46% and 27%, separately, compared with that of the TIG. The grain sizes in the PU-TIG were smaller than that of the TIG. The minimu...

A new welding process was named as pulsed ultrasonic assisted GTAW (PU-GTAW). In low-frequency of 1–20 Hz, the arc shape went through from expansion to contraction and re-expansion with the change of pulsed frequency, which was defined as pulsed arc. When the pulsed frequency was excessed 20 Hz, the PU-GTAW arc shape was compressed compared with th...

Pulsed ultrasonic assisted gas tungsten arc welding (PU-GTAW) is a newly developed welding method. In this work, the PU-GTAW and un-pulsed ultrasonic assisted gas tungsten arc welding (U-GTAW) was comparative investigated by analyzing the microstructure and mechanical properties of Q235 welded joints. The results showed that the improvement of PU-G...