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Experimental Study on Wire Melting Control Ability of Twin-Body Plasma Arc
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作者 Ruiying Zhang Fan Jiang Long Xue 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第2期184-194,共11页
The twin-body plasma arc has the decoupling control ability of heat transfer and mass transfer,which is beneficial to shape and property control in wire arc additive manufacturing.In this paper,with the wire feeding s... The twin-body plasma arc has the decoupling control ability of heat transfer and mass transfer,which is beneficial to shape and property control in wire arc additive manufacturing.In this paper,with the wire feeding speed as a characteristic quantity,the wire melting control ability of twin-body plasma arc was studied by adjusting the current separation ratio(under the condition of a constant total current),the wire current/main current and the position of the wire in the arc axial direction.The results showed that under the premise that the total current remains unchanged(100 A),as the current separation ratio increased,the middle and minimum melting amounts increased approximately synchronously under the effect of anode effect power,the first melting mass range remained constant;the maximum melting amount increased twice as fast as the middle melting amount under the effect of the wire feeding speed,and the second melting mass range was expanded.When the wire current increased,the anode effect power and the plasma arc power were both factors causing the increase in the wire melting amount;however,when the main current increased,the plasma arc power was the only factor causing the increase in the wire melting amount.The average wire melting increment caused by the anode effect power was approximately 2.7 times that caused by the plasma arc power.The minimum melting amount was not affected by the wire-torch distance under any current separation ratio tested.When the current separation ratio increased and reached a threshold,the middle melting amount remained constant with increasing wire-torch distance.When the current separation ratio continued to increase and reached the next threshold,the maximum melting amount remained constant with the increasing wire-torch distance.The effect of the wire-torch distance on the wire melting amount reduced with the increase in the current separation ratio.Through this study,the decoupling mechanism and ability of this innovative arc heat source is more clearly. 展开更多
关键词 Twin-body plasma arc melting control ability melting amount Current separation ratio
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Interplay of laser power and pore characteristics in selective laser melting of ZK60 magnesium alloys:A study based on in-situ monitoring and image analysis 被引量:1
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作者 Weijie Xie Hau-Chung Man Chi-Wai Chan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第4期1346-1366,共21页
This study offers significant insights into the multi-physics phenomena of the SLM process and the subsequent porosity characteristics of ZK60 Magnesium(Mg)alloys.High-speed in-situ monitoring was employed to visualis... This study offers significant insights into the multi-physics phenomena of the SLM process and the subsequent porosity characteristics of ZK60 Magnesium(Mg)alloys.High-speed in-situ monitoring was employed to visualise process signals in real-time,elucidating the dynamics of melt pools and vapour plumes under varying laser power conditions specifically between 40 W and 60 W.Detailed morphological analysis was performed using Scanning-Electron Microscopy(SEM),demonstrating a critical correlation between laser power and pore formation.Lower laser power led to increased pore coverage,whereas a denser structure was observed at higher laser power.This laser power influence on porosity was further confirmed via Optical Microscopy(OM)conducted on both top and cross-sectional surfaces of the samples.An increase in laser power resulted in a decrease in pore coverage and pore size,potentially leading to a denser printed part of Mg alloy.X-ray Computed Tomography(XCT)augmented these findings by providing a 3D volumetric representation of the sample internal structure,revealing an inverse relationship between laser power and overall pore volume.Lower laser power appeared to favour the formation of interconnected pores,while a reduction in interconnected pores and an increase in isolated pores were observed at higher power.The interplay between melt pool size,vapour plume effects,and laser power was found to significantly influence the resulting porosity,indicating a need for effective management of these factors to optimise the SLM process of Mg alloys. 展开更多
关键词 Selective laser melting(SLM) Magnesium(Mg)alloys Biodegradable implants POROSITY In-situ monitoring
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Melting geodynamics reveals a subduction origin for the Purang ophiolite,Tibet,China
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作者 Tao Ruan Zhong-Jie Bai +1 位作者 Wei-Guang Zhu Shi-Ji Zheng 《Acta Geochimica》 EI CAS CSCD 2024年第4期754-773,共20页
The debate regarding whether the Yarlung-Zangbo ophiolite(YZO)on the south of the Qinghai-Tibet Plateau,formed in a mid-ocean ridge(MOR)or a supra-subduction zone(SSZ)setting has remained unresolved.Here we present pe... The debate regarding whether the Yarlung-Zangbo ophiolite(YZO)on the south of the Qinghai-Tibet Plateau,formed in a mid-ocean ridge(MOR)or a supra-subduction zone(SSZ)setting has remained unresolved.Here we present petrological,mineralogical,and geochemical data associated with modeling melting geodynamics of the mantle peridotites from the Purang ophiolite in the western segment of the Yarlung-Zangbo Suture Zone(YZSZ)to explore its tectonic environment.The Purang lherzolites are characterized by the protogranular texture and have abyssal-peridotite-like mineral compositions,including low Cr^(#)(20-30)and TiO_(2) contents(<0.1wt%)in spinel,high Al_(2)O_(3)(2.9wt%-4.4wt%)and CaO(1.9wt%-3.7wt%)contents in orthopyroxene and LREE-depletion in clinopyroxene.Compositions of these lherzolites can be modeled by~11%dynamic melting of the DMM source with a small fraction of melt(~0.5%)entrapped within the source,a similar melting process to typical abyssal peridotites.The Purang harzburgites are characterized by the porphyroclastic texture and exhibit highly refractory mineral compositions such as high spinel Cr^(#)(40-68),low orthopyroxene Al_(2)O_(3)(<2.2wt%)and CaO(<1.1wt%)contents.Clinopyroxenes in these harzburgites are enriched in Sr(up to 6.0 ppm)and LREE[(Ce)N=0.02-0.4],but depleted in Ti(200 ppm,on average)and HREE[(Yb)N<2].Importantly,the more depleted samples tend to have higher clinopyroxene Sr and LREE contents.These observations indicate an open-system hydrous melting with a continuous influx of slab fluid at a subduction zone.The modeled results show that these harzburgites could be formed by 19%-23%hydrous melting with the supply rate of slab fluid at 0.1%-1%.The lower clinopyroxene V/Sc ratios in harzburgites than those in lherzolites suggest a high oxidation stage of the melting system of harzburgites,which is consistent with a hydrous melting environment for these harzburgites.It is therefore concluded that the Purang ophiolite has experienced a transformation of tectonic setting from MOR to SSZ. 展开更多
关键词 melting geodynamics SSZ peridotites MOR peridotites CLINOPYROXENE Purang ophiolite
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High-strength and thermally stable TiB_(2)-modified Al-Mn-Mg-Er-Zr alloy fabricated via selective laser melting
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作者 Jiang Yu Yaoxiang Geng +6 位作者 Yongkang Chen Xiao Wang Zhijie Zhang Hao Tang Junhua Xu Hongbo Ju Dongpeng Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第10期2221-2232,共12页
To increase the processability and plasticity of the selective laser melting(SLM)fabricated Al-Mn-Mg-Er-Zr alloys,a novel TiB_(2)-modified Al-Mn-Mg-Er-Zr alloy with a mixture of Al-Mn-Mg-Er-Zr and nano-TiB_(2) powders... To increase the processability and plasticity of the selective laser melting(SLM)fabricated Al-Mn-Mg-Er-Zr alloys,a novel TiB_(2)-modified Al-Mn-Mg-Er-Zr alloy with a mixture of Al-Mn-Mg-Er-Zr and nano-TiB_(2) powders was fabricated by SLM.The pro-cessability,microstructure,and mechanical properties of the alloy were systematically investigated by density measurement,microstruc-ture characterization,and mechanical properties testing.The alloys fabricated at 250 W displayed higher relative densities due to a uni-formly smooth top surface and appropriate laser energy input.The maximum relative density value of the alloy reached(99.7±0.1)%,demonstrating good processability.The alloy exhibited a duplex grain microstructure consisting of columnar regions primarily and equiaxed regions with TiB_(2),Al6Mn,and Al3Er phases distributed along the grain boundaries.After directly aging treatment at a high tem-perature of 400℃,the strength of the SLM-fabricated TiB_(2)/Al-Mn-Mg-Er-Zr alloy increased due to the precipitation of the secondary Al6Mn phases.The maximum yield strength and ultimate tensile strength of the aging alloy were measured to be(374±1)and(512±13)MPa,respectively.The SLM-fabricated TiB_(2)/Al-Mn-Mg-Er-Zr alloy demonstrates exceptional strength and thermal stability due to the synergistic effects of the inhibition of grain growth,the incorporation of TiB_(2) nanoparticles,and the precipitation of secondary Al6Mn nanoparticles. 展开更多
关键词 selective laser melting aluminum alloy PROCESSABILITY mechanical properties thermal stability
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Mitigation of black carbon emissions could immediately reduce 6.3% of glacier melting in the Qilian Mountains
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作者 Ji-Zu CHEN Wen-Tao DU +6 位作者 Shi-Chang KANG Xiang QIN Wei-Jun SUN Li-Hui LUO Yang LI Jun-Hua YANG You-Yan JIANG 《Advances in Climate Change Research》 SCIE CSCD 2024年第4期725-736,共12页
Global warming in tandem with surface albedo reduction caused by black carbon(BC)deposition on glaciers accelerated glacier melting;however,their respective contributions remain unclear.Glaciers in the Qilian Mountain... Global warming in tandem with surface albedo reduction caused by black carbon(BC)deposition on glaciers accelerated glacier melting;however,their respective contributions remain unclear.Glaciers in the Qilian Mountains are crucial for the development of oases in the Hexi Corridor;however,their area has decreased by more than 20%over the past half-century.Thus,this study developed a dynamic deposition model for light-absorbing particles(LAPs),coupled with a surface energy and mass balance model.We comprehensively assessed the effects of BC and warming on the melting of a typical glacier in the Qilian Mountains based on the coupled model.BC on the glacier surface caused 13.1%of annual glacier-wide melting,of which directly deposited atmospheric BC reduced the surface albedo by 0.02 and accounted for 9.1%of glacier melting.The air temperature during 2000-2010 has increased by 1.5°C relative to that during the 1950s,accounting for 51.9%of current glacier melting.Meanwhile,BC emission have increased by 4.6 times compared to those of the early Industrial Revolution recorded in an ice core,accounting conservatively for 6.3%of current glacier melting.Mitigating BC emissions has a limited influence on current glacier melting;however,in the long-term,mitigation should exert a noteworthy impact on glacier melting through the self-purification of glaciers. 展开更多
关键词 GLACIER melting Black carbon Simulation Qilian Mountains
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Stability and melting behavior of boron phosphide under high pressure
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作者 梁文嘉 向晓君 +2 位作者 李倩 梁浩 彭放 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期579-584,共6页
Boron phosphide(BP)has gained significant research attention due to its unique photoelectric and mechanical properties.In this work,we investigated the stability of BP under high pressure using x-ray diffraction and s... Boron phosphide(BP)has gained significant research attention due to its unique photoelectric and mechanical properties.In this work,we investigated the stability of BP under high pressure using x-ray diffraction and scanning electron microscope.The phase diagram of BP was explored in both B-rich and P-rich environments,revealing crucial insight into its behavior at 5.0 GPa.Additionally,we measured the melting curve of BP from 8.0 GPa to 15.0 GPa.Our findings indicate that the stability of BP under high pressure is improved within B-rich and P-rich environments.Furthermore,we report a remarkable observation of melting curve frustration at 10.0 GPa.This study will enhance our understanding of stability of BP under high pressure,shedding light on its potential application in semiconductor,thermal,and light-transmitting devices. 展开更多
关键词 boron phosphide STABILITY melting curve high pressure
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Effects of processing parameters on fabrication defects,microstructure and mechanical properties of additive manufactured Mg–Nd–Zn–Zr alloy by selective laser melting process
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作者 Wenyu Xu Penghuai Fu +4 位作者 Nanqing Wang Lei Yang Liming Peng Juan Chen Wenjiang Ding 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第6期2249-2266,共18页
Mg–3Nd–0.2Zn–0.4Zr(NZ30K,wt.%)alloy is a new kind of high-performance metallic biomaterial.The combination of the NZ30K Magnesium(Mg)alloy and selective laser melting(SLM)process seems to be an ideal solution to pr... Mg–3Nd–0.2Zn–0.4Zr(NZ30K,wt.%)alloy is a new kind of high-performance metallic biomaterial.The combination of the NZ30K Magnesium(Mg)alloy and selective laser melting(SLM)process seems to be an ideal solution to produce porous Mg degradable implants.However,the microstructure evolution and mechanical properties of the SLMed NZ30K Mg alloy were not yet studied systematically.Therefore,the fabrication defects,microstructure,and mechanical properties of the SLMed NZ30K alloy under different processing parameters were investigated.The results show that there are two types of fabrication defects in the SLMed NZ30K alloy,gas pores and unfused defects.With the increase of the laser energy density,the porosity sharply decreases to the minimum first and then slightly increases.The minimum porosity is 0.49±0.18%.While the microstructure varies from the large grains with lamellar structure inside under low laser energy density,to the large grains with lamellar structure inside&the equiaxed grains&the columnar grains under middle laser energy density,and further to the fine equiaxed grains&the columnar grains under high laser energy density.The lamellar structure in the large grain is a newly observed microstructure for the NZ30K Mg alloy.Higher laser energy density leads to finer grains,which enhance all the yield strength(YS),ultimate tensile strength(UTS)and elongation,and the best comprehensive mechanical properties obtained are YS of 266±2.1 MPa,UTS of 296±5.2 MPa,with an elongation of 4.9±0.68%.The SLMed NZ30K Mg alloy with a bimodal-grained structure consisting of fine equiaxed grains and coarser columnar grains has better elongation and a yield drop phenomenon. 展开更多
关键词 Selective laser melting Mg alloy Processing parameter Lamellar structure Bimodal-grained structure
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Effects of projectile parameters on the momentum transfer and projectile melting during hypervelocity impact
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作者 Wenjin Liu Qingming Zhang +6 位作者 Renrong Long Zizheng Gong Ren Jiankang Xin Hu Siyuan Ren Qiang Wu Guangming Song 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期89-103,共15页
The effects of projectile/target impedance matching and projectile shape on energy,momentum transfer and projectile melting during collisions are investigated by numerical simulation.By comparing the computation resul... The effects of projectile/target impedance matching and projectile shape on energy,momentum transfer and projectile melting during collisions are investigated by numerical simulation.By comparing the computation results with the experimental results,the correctness of the calculation and the statistical method of momentum transfer coefficient is verified.Different shapes of aluminum,copper and heavy tungsten alloy projectiles striking aluminum,basalt,and pumice target for impacts up to 10 km/s are simulated.The influence mechanism of the shape of the projectile and projectile/target density on the momentum transfer was obtained.With an increase in projectile density and length-diameter ratio,the energy transfer time between the projectile and targets is prolonged.The projectile decelerates slowly,resulting in a larger cratering depth.The energy consumed by the projectile in the excavation stage increased,resulting in lower mass-velocity of ejecta and momentum transfer coefficient.The numerical simulation results demonstrated that for different projectile/target combinations,the higher the wave impedance of the projectile,the higher the initial phase transition velocity and the smaller the mass of phase transition.The results can provide theoretical guidance for kinetic impactor design and material selection. 展开更多
关键词 Hypervelocity impact Energy partitioning Impact melting Momentum transfer
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Selective Laser Melting of Novel SiC and TiC Strengthen 7075 Aluminum Powders for Anti-Cracks Application
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作者 Yingjie Li Hanlin Liao 《Journal of Materials Science and Chemical Engineering》 2024年第4期136-142,共7页
The aerospace and military sectors have widely used AA7075, a type of 7075 aluminum alloy, due to its exceptional mechanical performance. Selective laser melting (SLM) is a highly effective method for producing intric... The aerospace and military sectors have widely used AA7075, a type of 7075 aluminum alloy, due to its exceptional mechanical performance. Selective laser melting (SLM) is a highly effective method for producing intricate metallic components, particularly in the case of aluminum alloys like Al-Si-Mg. Nevertheless, the production of high-strength AA7075 by SLM is challenging because of its susceptibility to heat cracking and elemental vaporization. In this study, AA7075 powders were mechanically mixed with SiC and TiC particles. Subsequently, this new type of AA7075 powder was effectively utilized in green laser printing to create solid components with fine-grain strengthening microstructures consisting of equiaxial grains. These as-printed parts exhibit a tensile strength of up to 350 MPa and a ductility exceeding 2.1%. Hardness also increases with the increasing content of mixed powder, highlighting the essential role of SiC and TiC in SLM for improved hardness and tensile strength performance. . 展开更多
关键词 Selective Laser melting (SLM) AA 7075 Fine Grain Strengthen TiC SIC Green Laser
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The long-lived partial melting of the Greater Himalayas in southern Tibet, constraints from the Miocene Gyirong anatectic pegmatite and its prospecting potential for rare element minerals 被引量:6
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作者 Hua-wen Cao Qiu-ming Pei +6 位作者 Xiao Yu Ai-bin Cao Yong Chen Hang Liu Kai Zhang Xin Liu Xiang-fei Zhang 《China Geology》 CAS CSCD 2023年第2期303-321,I0004-I0015,共31页
The Cenozoic Himalayan leucogranite-pegmatite belt has been a hotspot for rare metal exploration in recent years.To determine the genesis of the pegmatite in the Himalayan region and its relationship with the Greater ... The Cenozoic Himalayan leucogranite-pegmatite belt has been a hotspot for rare metal exploration in recent years.To determine the genesis of the pegmatite in the Himalayan region and its relationship with the Greater Himalayan Crystalline Complex(GHC),the Gyirong pegmatite in southern Tibet was chosen for geochronological and geochemical studies.The dating analyses indicate that the U-Th-Pb ages of zircon,monazite,and xenotime exhibit large variations(38.6‒16.1 Ma),with the weighted average value of the four youngest points is 16.5±0.3 Ma,which indicates that the final stage of crystallization of the melt occurred in the Miocene.The age of the muscovite Ar-Ar inverse isochron is 15.2±0.4 Ma,which is slightly later than the intrusion age,showing that a cooling process associated with rapid denudation occurred at 16‒15 Ma.TheεHf(t)values of the Cenozoic anatectic zircons cluster between−12 and−9 with an average of−11.4.The Gyirong pegmatite shows high contents of Si,Al,and K,a high Al saturation index,and low contents of Na,Ca,Fe,Mn,P,Mg,and Ti.Overall,the Gyirong pegmatite is enriched in Rb,Cs,U,K,Th and Pb and depleted in Nb,Ta,Zr,Ti,Eu,Sr,and Ba.The samples show a high 87Sr/86Sr(16 Ma)ratio of ca.0.762 and a lowεNd(16 Ma)value of−16.0.The calculated average initial values of 208Pb/204Pb(16 Ma),207Pb/204Pb(16 Ma)and 206Pb/204Pb(16 Ma)of the whole rock are 39.72,15.79 and 19.56,respectively.The Sr-Nd-Pb-Hf isotopic characteristics of the Gyirong pegmatite are consistent with those of the GHC.This study concludes that the Gyirong pegmatite represents a typical crustal‒derived anatectic pegmatite with low metallogenic potential for rare metals.The Gyirong pegmatite records the long‒term metamorphism and partial melting process of the GHC,and reflects the crustal thickening caused by thrust compression at 39‒29 Ma and the crustal thinning induced by extensional decompression during 28‒15 Ma. 展开更多
关键词 Partial melting of magma Anatectic pegmatite Zircon-monazite-xenotime U‒Pb dating Sr-Nd-Pb isotopes Greater Himalayan crystalline complex Mineral exploration engineering Gyirong Tibet
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Petrogenesis of the Late Eocene to Early Oligocene Yao'an Shoshonitic Complex,Southeastern Tibet:Partial Melting of an Ancient Continental Lithospheric Mantle beneath the Yangtze Block 被引量:2
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作者 DONG Mengmeng YANG Tiannan +3 位作者 XUE Chuandong XIN Di LIANG Mingjuan YAN Qinggao 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2023年第6期1657-1670,共14页
Cenozoic potassic-ultrapotassic igneous rocks are widespread in the southeastern Tibetan Plateau.Their petrogenesis and magmatic processes remain subject to debate in spite of numerous publications.Almost all of the C... Cenozoic potassic-ultrapotassic igneous rocks are widespread in the southeastern Tibetan Plateau.Their petrogenesis and magmatic processes remain subject to debate in spite of numerous publications.Almost all of the Cenozoic extrusive and intrusive rocks in the Yao’an area,western Yunnan Province,SW China,are geochemically shoshonitic,collectively termed here the Yao’an Shoshonitic Complex(YSC).The YSC is located in the(south)easternmost part of the ENE-WSW-trending,~550 km-long and~250 km-wide Cenozoic magmatic zone;the latter separates the orthogonal and oblique collision belts of the India-Eurasia collision orogen.Previously published geochronological and thermochronological data revealed that the rocks of the YSC were emplaced over a short timespan of 34-32 Ma.This and our new data suggest that the primary magma of the YSC likely was formed by partial melting of ancient continental lithospheric mantle beneath the Yangtze Block.This part of the continental lithospheric mantle had likely not been modified by any oceanic subduction.Fractionation crystallization of an Mg-and Ca-bearing mineral and TiFe oxides during the magmatic evolution probably account for the variable lithologies of the YSC. 展开更多
关键词 Ancient continental lithospheric mantle Partial melting Yao’an Shoshonitic Complex Late Eocene to early Oligocene SE Tibetan Plateau
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Effects of heat input on layer heterogeneity of selective laser melting Ti-6Al-4V components 被引量:2
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作者 陈昌荣 刘畅 +4 位作者 王乾廷 练国富 黄旭 冯美艳 戴继成 《China Welding》 CAS 2023年第3期51-66,共16页
Due to the layer-by-layer manufacturing characteristics,metallurgical process of selective laser melting(SLM)is inherently dif-ferent in the building direction because of varying conditions,thereby resulting inter-lay... Due to the layer-by-layer manufacturing characteristics,metallurgical process of selective laser melting(SLM)is inherently dif-ferent in the building direction because of varying conditions,thereby resulting inter-layer heterogeneity.To mitigate such anisotropy,it is of great significance to understand the effects of processing parameters on the property evolution and thus metallurgy of fabrication process.This research proposes one-factor-at-a-time experiment to investigate the influences of laser power and scanning speed on the surface qual-ity,microstructures and mechanical properties of selective laser melted Ti-6Al-4V parts.Surface quality is assessed by roughness around the printings while mechanical properties are evaluated through microhardness and tensile strengths.Phases in microstructure are quantified by XRD to correlate with mechanical properties.Fracture morphology is analyzed to understand the effect of defects and microstructure on mechanical performance.The optimized parameter corresponding to best surface quality and mechanical properties has been found respect-ively in laser power of 190 W and scanning speed of 800 mm/s.After optimization,surface roughness has decreased by 44.47%for upper surface.Yielding strength,tensile strength and elongation rate have improved by 13.17%,43.34%and 64.51%,respectively,with similar hardness and Young’s modulus.In addition,heterogeneity of mechanical properties has great improvement by a range of 31.63%-92.68%. 展开更多
关键词 selective laser melting TI-6AL-4V inter-layer heterogeneity tensile properties heat input
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Metallurgical properties of CaO–SiO_(2)–Al_(2)O_(3)–4.6wt%MgO–Fe_(2)O_(3)slag system pertaining to spent automotive catalyst smelting 被引量:1
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作者 Ruili Zheng Jianfang Lü +5 位作者 Weifeng Song Mudan Liu Huashan Li Yong Liu Xianjin Lü Zhiyuan Ma 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第5期886-896,共11页
The metallurgical properties of the CaO–SiO_(2)–Al_(2)O_(3)–4.6wt%Mg O–Fe_(2)O_(3)slag system,formed by the co-treatment process of spent automotive catalyst(SAC)and copper-bearing electroplating sludge(CBES),were... The metallurgical properties of the CaO–SiO_(2)–Al_(2)O_(3)–4.6wt%Mg O–Fe_(2)O_(3)slag system,formed by the co-treatment process of spent automotive catalyst(SAC)and copper-bearing electroplating sludge(CBES),were studied systematically in this paper.The slag structure,melting temperature,and viscous characteristics were investigated by Fourier transform infrared(FTIR)spectroscopy,Raman spectroscopy,Fact Sage calculation,and viscosity measurements.Experimental results show that the increase of Fe_(2)O_(3)content(3.8wt%–16.6wt%),the mass ratio of CaO/SiO_(2)(m(CaO)/m(SiO_(2)),0.5–1.3),and the mass ratio of SiO_(2)/Al_(2)O_(3)(m(SiO_(2))/m(Al_(2)O_(3)),1.0–5.0)can promote the depolymerization of silicate network,and the presence of a large amount of Fe_(2)O_(3)in form of tetrahedral and octahedral units ensures the charge compensation of Al^(3+)ions and makes Al_(2)O_(3)only behave as an acid oxide.Thermodynamic calculation and viscosity measurements show that with the increase of Fe_(2)O_(3)content,m(Ca O)/m(SiO_(2)),and m(SiO_(2))/m(Al_(2)O_(3)),the depolymerization of silicate network structure and low-melting-point phase transformation first occur within the slag,leading to the decrease in melting point and viscosity of the slag,while further increase causes the formation of high-melting-point phase and a resultant re-increase in viscosity and melting point.Based on experimental analysis,the preferred slag composition with low polymerization degree,viscosity,and melting point is as follows:Fe_(2)O_(3)content of 10.2wt%–13.4wt%,m(CaO)/m(SiO_(2))of 0.7–0.9 and m(SiO_(2))/m(Al_(2)O_(3))of 3.0–4.0.This work provides a theoretical support for slag design in co-smelting process of SAC and CBES. 展开更多
关键词 spent automotive catalyst co-treatment slag system slag structure melting temperature phase transformation VISCOSITY
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The Processes-Based Attributes of Four Major Surface Melting Events over the Antarctic Ross Ice Shelf 被引量:1
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作者 Wenyi LI Yuting WU Xiaoming HU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第9期1662-1670,共9页
The Ross-Amundsen sector is experiencing an accelerating warming trend and a more intensive advective influx of marine air streams.As a result,massive surface melting events of the ice shelf are occurring more frequen... The Ross-Amundsen sector is experiencing an accelerating warming trend and a more intensive advective influx of marine air streams.As a result,massive surface melting events of the ice shelf are occurring more frequently,which puts the West Antarctica Ice Sheet at greater risk of degradation.This study shows the connection between surface melting and the prominent intrusion of warm and humid air flows from lower latitudes.By applying the Climate Feedback-Response Analysis Method(CFRAM),the temporal surge of the downward longwave(LW)fluxes over the surface of the Ross Ice Shelf(RIS)and adjacent regions are identified for four historically massive RIS surface melting events.The melting events are decomposed to identify which physical mechanisms are the main contributors.We found that intrusions of warm and humid airflow from lower latitudes are conducive to warm air temperature and water vapor anomalies,as well as cloud development.These changes exert a combined impact on the abnormal enhancement of the downward LW surface radiative fluxes,significantly contributing to surface warming and the resultant massive melting of ice. 展开更多
关键词 Ross Ice Shelf(RIS) surface melting warm and humid air advection downward longwave radiation Climate Feedback-Response Analysis Method(CFRAM)
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Microstructure,Properties and Crack Suppression Mechanism of High-speed Steel Fabricated by Selective Laser Melting at Different Process Parameters
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作者 Wenbin Ji Chuncheng Liu +1 位作者 Shijie Dai Riqing Deng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第2期91-105,共15页
To enrich material types applied to additive manufacturing and enlarge application scope of additive manufacturing in conformal cooling tools,M2 high-speed steel specimens were fabricated by selective laser melting(SL... To enrich material types applied to additive manufacturing and enlarge application scope of additive manufacturing in conformal cooling tools,M2 high-speed steel specimens were fabricated by selective laser melting(SLM).Effects of SLM parameters on the microstructure and mechanical properties of M2 high-speed steel were investigated.The results showed that substrate temperature and energy density had significant influence on the densification process of materials and defects control.Models to evaluate the effect of substrate temperature and energy density on hardness were studied.The optimized process parameters,laser power,scan speed,scan distance,and substrate temperature,for fabricated M2 are 220 W,960 mm/s,0.06 mm,and 200℃,respectively.Based on this,the hardness and tensile strength reached 60 HRC and 1000 MPa,respectively.Interlaminar crack formation and suppression mechanism and the relationship between temperature gradient and thermal stress were illustrated.The inhibition effect of substrate temperature on the cracks generated by residual stresses was also explained.AM showed great application potential in the field of special conformal cooling cutting tool preparation. 展开更多
关键词 Selective laser melting High-speed steel Mechanical properties MICROSTRUCTURE Interlaminar cracks
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Influence of heat treatments on incipient melting structures of DD5 nickel-based single crystal superalloy
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作者 Zhi-hong Jia Chen-yang Li +4 位作者 Wen-xiang Jing Xiang-feng Liang Ze-kun Zhang Jia-le Xiao Yu-tao Zhao 《China Foundry》 SCIE CAS CSCD 2023年第5期395-402,共8页
The evolution of microstructure and formation mechanism of incipient melting microstructure of DD5 single crystal superalloy during solution heat treatment were studied by scanning electron microscopy(SEM),electron pr... The evolution of microstructure and formation mechanism of incipient melting microstructure of DD5 single crystal superalloy during solution heat treatment were studied by scanning electron microscopy(SEM),electron probe microanalysis(EPMA),and energy dispersive spectroscopy(EDS).The solidus and liquidus of single crystal alloy were obtained by differential scanning calorimetry(DSC).Results show that the mosaic-like eutectic and fan-like eutectic are dissolved at first,and the coarseγ'phase is dissolved later during the solution heat treatment of 1,390°C/2 h+1,310°C/4 h+1,320°C/10 h+air cooling(AC).The composition segregations of Al,Ta,W and Re are 0.99,0.96,1.04 and 1.16,respectively,which close to 1.The incipient melting is caused by the low local temperature of the alloy,and the micropore region with a lower melting point is the preferred position for incipient melting. 展开更多
关键词 SUPERALLOY solution heat treatment EUTECTIC composition segregation incipient melting
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Surface Integrity of Inconel 738LC Parts Manufactured by Selective Laser Melting Followed by High-speed Milling
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作者 Guanhui Ren Sai Guo Bi Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第1期65-79,共15页
This study is concerned with the surface integrity of Inconel 738LC parts manufactured by selective laser melting(SLM)followed by high-speed milling(HSM).In the investigation process of surface integrity,the study emp... This study is concerned with the surface integrity of Inconel 738LC parts manufactured by selective laser melting(SLM)followed by high-speed milling(HSM).In the investigation process of surface integrity,the study employs ultradepth three-dimensional microscopy,laser scanning confocal microscopy,scanning electron microscopy,electron backscatter diffractometry,and energy dispersive spectroscopy to characterize the evolution of material microstructure,work hardening,residual stress coupling,and anisotropic effect of the building direction on surface integrity of the samples.The results show that SLM/HSM hybrid manufacturing can be an effective method to obtain better surface quality with a thinner machining metamorphic layer.High-speed machining is adopted to reduce cutting force and suppress machining heat,which is an effective way to produce better surface mechanical properties during the SLM/HSM hybrid manufacturing process.In general,high-speed milling of the SLM-built Inconel 738LC samples offers better surface integrity,compared to simplex additive manufacturing or casting. 展开更多
关键词 Surface integrity Inconel 738LC Selective laser melting High-speed milling
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Assessment of the Mechanical Properties of Carbon-Fiber Heating Cables in Snow and Ice Melting Applications
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作者 Zhiyong Yang Jiacheng Zhang +3 位作者 Henglin Xiao Zhi Chen Tian Bao Yin Liu 《Fluid Dynamics & Materials Processing》 EI 2023年第9期2267-2288,共22页
The use of carbon-fiber heating cables(CFHC)to achieve effective melting of snow and ice deposited on roads is a method used worldwide.In this study,tensile and compressive tests have been conducted to analyze the mech... The use of carbon-fiber heating cables(CFHC)to achieve effective melting of snow and ice deposited on roads is a method used worldwide.In this study,tensile and compressive tests have been conducted to analyze the mechan-ical properties of the CFHC and assess whether the maximum tensile and compressive strengths can meet the pavement design specifications.In order to study the aging produced by multiple cycles of heating and cooling,in particular,the CFHC was repeatedly heated in a cold chamber with an ambient temperature ranging between-20℃ and+40℃.Moreover,to evaluate how the strength of the pavement is affected by its presence,the CFHC was embedded at different depths and concrete blocks with different curing ages were subjected to relevant com-pression and splitting tensile tests.Numerical simulations based on the ANSYS software have also been performed and compared with the outcomes of the static loading tests.The results show that the CFHC embedded in the concrete does not affect the compressive splitting tensile strengths of the pavement.Overall,the CFHC meets the conditions required for continued use in road ice melting applications. 展开更多
关键词 Carbon fiber cable snow and ice melting concrete pavement compressive strength splitting tensile strength
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Impact of Melting Heat Transfer and Variable Characteristics on an MHD Non-Newtonian Shear-Thinning Fluid Flow with Gyrotactic Microorganisms over a Nonlinear Stretched Surface
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作者 Muhammad Ramzan Naila Shaheen 《Journal of Applied Mathematics and Physics》 2023年第8期2461-2471,共11页
The objective of this work is to examine how temperature-dependent thermal conductivity and concentration-dependent molecular diffusion affect Reiner-Philippoff nanofluid flow past a nonlinear stretching sheet. At the... The objective of this work is to examine how temperature-dependent thermal conductivity and concentration-dependent molecular diffusion affect Reiner-Philippoff nanofluid flow past a nonlinear stretching sheet. At the interface of the elongated surface zero-mass flux and melting heat condition are incorporated. The formulated mathematical problem is simplified by implementing suitable similarity transformations. For the numerical solution bvp4c is utilized. The parameters emerging in the model are discussed versus allied profiles through graphical illustrations. It is perceived that the velocity of the fluid decays on incrementing the Bingham number. The gyrotactic microorganism profile declines on amplifying the Peclet number. The validation of the proposed model is also added to this study. . 展开更多
关键词 Reiner-Philippoff Nanofluid Nonlinear Stretching Sheet melting Heat Transfer Gyrotactic Micro-Organisms
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Burner effects on melting process of regenerative aluminum melting furnace 被引量:2
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作者 王计敏 许朋 +4 位作者 闫红杰 周孑民 李世轩 贵广臣 李文科 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第10期3125-3136,共12页
According to the features of melting process of regenerative aluminum melting furnaces, a three-dimensional mathematical model with user-developed melting model, burner reversing and burning capacity model was establi... According to the features of melting process of regenerative aluminum melting furnaces, a three-dimensional mathematical model with user-developed melting model, burner reversing and burning capacity model was established. The numerical simulation of melting process of a regenerative aluminum melting furnace was presented using hybrid programming method of FLUENT UDF and FLUENT scheme based on the heat balance test. Burner effects on melting process of aluminum melting furnaces were investigated by taking optimization regulations into account. The change rules of melting time on influence factors are achieved. Melting time decreases with swirl number, vertical angle of burner, air preheated temperature or natural gas flow; melting time firstly decreases with horizontal angle between burners or air-fuel ratio, then increases; melting time increases with the height of burner. 展开更多
关键词 regenerative aluminum melting furnace BURNER melting process numerical simulation multi-element non-linearregression
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