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Feasibility analysis and process characteristics of selective laser ablation assisted milling Inconel 718

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Advances in Manufacturing 2022年第4期10卷 495-519页

作者： Bao-Yu Zhang Yu-Ning Zeng Xue-Qin Pang Song-Qing Li Xiao Liu Wen-Jun Deng School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou510641People’s Republic of China

laser-assisted machining(LAM),as one of the most efficient ways,has been employed to improve the machinability of nickel-based superalloys.However,the conventional LAM process usually used high power laser with large spot size,easily leading to high processing costs and overheating of bulk materials.In this paper,a new approach of selective laser ablation assisted milling(SLA-Mill)process for nickel-based superalloys was proposed,in which low power laser with small spot size was used to selectively ablate the uncut surface in front of the cutting tool,resulting in plentiful surface defects emerging.Such defects would significantly weaken the mechanical strength of difficult-to-cut materials,which was different from the thermal“softening”principle of conventional LAM.Thus,the laser ablation effect with low power and small spot size was first studied.The relationship between process parameters(e.g.,laser power,cutting speed and cutting depth)and process characteristics of SLA-Mill(e.g.,chip morphology,tool wear and surface integrity)was systematically discussed.Moreover,the chip formation mechanism in the SLA-Mill process was indepth analyzed.Results show that the SLA-Mill process is an effective approach for enhancing the machinability of nickel-based superalloys.The resultant cutting force has a reduction of about 30%at laser power of 60 W,cutting speed of 90 m/min,and cutting depth of 0.1 mm.Furthermore,the chip formation,tool wear,and surface integrity have improved significantly.In general,this paper provides a new route for the application of LAM technology.

关键词： laser-assisted machining(LAM) Nickel-based superalloys laser ablation Machinability Milling

Nanosecond laser preheating effect on ablation morphology and plasma emission in collinear dual-pulse laser-induced breakdown spectroscopy

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Plasma Science and Technology 2022年第11期24卷 145-150页

作者：李娜 Edward HAREFA 周卫东 Key Laboratory of Optical Information Detection and Display Technology of Zhejiang Zhejiang Normal UniversityJinhua 321004People’s Republic of China

Focus-offset collinear dual-pulse laser-induced breakdown spectroscopy is designed and used to investigate the laser ablation and spectral intensity with an aluminum alloy sample.The laser crater morphologies and ablation volumes were measured.An inter-pulse time delay dependent ablation efficiency on a nanosecond laser-heated sample was observed,which was similar to the trend of spectral intensity versus inter-pulse time delay in the delay time less than 3μs.Based on the observation,the nanosecond pulse laser preheating effect on subsequent second laser ablation and signal enhancement is discussed,which will be helpful for understanding the ablation and signal enhancement mechanism in the standard collinear DP-LIBS technique.

关键词： enhancement mechanism laser ablation crater morphology target preheating

The Antibacterial Activities of Copper Oxide Nanoparticles Synthesized Using laser ablation in Different Surfactants against Streptococcus mutans

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Journal of Renewable Materials 2023年第5期11卷 2109-2123页

作者： Ruaa H.Abbas A.Kadhim Azhar M.Haleem laser and Optoelectronics Engineering Department University of Technology-IraqBaghdadIraq Environmental Research Center University of Technology-IraqBaghdadIraq

Copper oxide nanoparticles(CuO NPs)were synthesised with laser ablation of a copper sheet immersed in deionized water(DW),cetrimonium bromide(CTAB),and sodium dodecyl sulphate(SDS),respectively.The target was irradiated with a pulsed Nd:YAG laser at 1064 nm,600 mJ,a pulse duration of 10 ns,and a repetition rate of 5 Hz.The CuO NPs colloidal were analyzed using UV–Vis spectroscopy,the Fourier transform infrared(FTIR)spectrometer,zeta potential(ZP),X-ray diffraction(XRD),transmission electron microscope(TEM)and field emission scanning electron microscopy(FESEM).The absorption spectra of CuO NPs colloidal showed peaks at 214,215 and 220 nm and low-intensity peaks at 645,650 and 680 nm for SDS,CTAB and DW,respectively.CuO NPs’colloidal results are(−21.6,1.2,and 80 mV)for negatively,neutrally,and positively charged SDS,DW,and CTAB,respectively.The XRD pattern of the NPs revealed the presence of CuO phase planes(110)(111),(20-2)and(11-1).The TEM images revealed nearly spherical NPs,with sizes ranging from 10–90,10–50,and 10–210 nm for CuO NPs mixed with DW,SDS and CTAB,respectively.FESEM images of all the synthesized samples illustrate the formation of spherical nanostructure and large particles are observable.The CuO NPs were tested for antibacterial activity against Streptococcus mutans by using the well diffusion method.In this method,CuO NPs prepared in DW at a concentration of 200μg/mL showed a greater inhibition zone against Streptococcus mutans.

关键词： Copper oxide nanoparticles(CuO NPs) laser ablation Streptococcus mutans

laser ablation of block copolymers with hydrogen-bonded azobenzene derivatives

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Frontiers of Chemical Science and Engineering 2018年第3期12卷 450-456页

作者： Jintang Huang Youju Huang Si Wu Max Planck Institute for Polymer Research Aekermannweg 10 55128 Mainz Germany Hefei National Laboratory for Physical Sciences at the Microscale CAS Key Laboratory of Soft Matter ChemistrY/ Anhui Key Laboratory ofOptoelcctronic Science and Technology Innovation Centre of Chemistry for Energy Materials Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 China

Supramolecular assemblies （PS-b-P4VP （AzoR）） are fabricated by hydrogen-bonding azobenzene derivatives （AzoR） to poly（4-vinyl pyridine） blocks of polystyrene-block-poly（4-vinyl pyridine）（PS-b-P4VP）. PS-b-P4VP（AzoR） forms phase separated nanostructures with a period of-75-105 nm. A second length scale structure with a period of 2μm is fabricated on phase separated PS-b-P4VP（AzoR） by laser interference abla- tion. Both the concentration and the substituent of AzoR in PS-b-P4VP（AzoR） affect the laser ablation process. The laser ablation threshold of PS-b-P4VP（AzoR） decreases as the concentration of AzoR increases. In PS-b-P4VP（AzoR） with different substituents （R = CN, H, and CH3）, ablation thresholds follow the trend： PS-b-P4VP（AzoCN）〈 PS-b- P4VP（AzoCH3）〈PS-b-P4VP（AzoH）. This result indicates that the electron donor group （CH3） and the electron acceptor group （CN） can lower the ablation threshold of PS-b-P4VP（AzoR）.

关键词： laser ablation block copolymers hydrogen-bond azobenzene derivatives supramolecular assembly

laser ablation and structuring of CdZnTe with femtosecond laser pulses

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Journal of Materials Science & Technology 2020年第13期47卷 180-185页

作者： J.J.J.Nivas E.Allahyari A.Vecchione Q.Hao S.Amoruso X.Wang Dipartimento di Fisica“Ettore Pancini” Universitàdi Napoli“Federico II”Via CintiaI-80126 NapoliItaly CNR-SPIN UOS NapoliVia CintiaI-80126 NapoliItaly CNR-SPIN UOS SalernoVia Giovanni Paolo II132I-84084 Fisciano(SA)Italy North China Research Institute of Electro-Optics Beijing 100015China School of Remote Sensing and Information Engineering Wuhan UniversityWuhan 430072China

We report an experimental investigation on laser ablation and associated surface structuring of CdZnTe by femtosecond Ti:Sa laser pulses(laser wavelengthλ≈800 nm,≈35 fs,10 Hz),in air.By exploiting different static irradiation conditions,the fluence threshold and the incubation effect in CdZnTe are estimated.Interestingly,surface treatment with a low laser fluence(laser pulse energy E≈5-10_μJ)and number of shots(5laser irradiation.Irradiation with a larger number of pulses(N≈500,1000)with higher pulse energies(E≈30-50μJ)results in the formation of welldefined laser-induced periodic surface structures(LIPSS)in the outskirts of the main crater,where the local fluence is well below the material ablation threshold.Both low spatial frequency and high spatial frequency LIPSS perpendicular to the laser polarization are found together and separately depending on the irradiation condition.These are ascribed to a process of progressive aggregation of randomly distributed nanoparticles produced during laser ablation of the deep crater in the region of the target irradiated by a fluence below the ablation threshold with many laser pulses.

关键词： laser ablation Femtosecond laser surface processing CdZnTe laser induced periodic surface structures laser processing

Investigations on MoS_(2)plasma by infra-red pulsed laser irradiation in high vacuum

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Plasma Science and Technology 2024年第7期26卷 123-133页

作者： Lorenzo TORRISI Letteria SILIPIGNI Alfio TORRISI Mariapompea CUTRONEO Dipartimento di Scienze Matematiche e Informatiche Scienze Fisiche e Scienze della TerraMIFTUniversitàdi MessinaMessina 98166Italy Faculty of Medicine and Surgery Kore University of EnnaEnna 94100Italy Nuclear Physics Institute of the CAS HusinecŘežPrague 25068Czech Republic

MoS_(2)targets were irradiated by infra-red(IR)pulsed laser in a high vacuum to determine hot plasma parameters,atomic,molecular and ion emission,and angular and charge state distributions.In this way,pulsed laser deposition(PLD)of thin films on graphene oxide substrates was also realized.An Nd:YAG laser,operating at the 1064 nm wavelength with a 5 ns pulse duration and up to a 1 J pulse energy,in a single pulse or at a 10 Hz repetition rate,was employed.ablation yield was measured as a function of the laser fluence.Plasma was characterized using different analysis techniques,such as time-of-flight measurements,quadrupole mass spectrometry and fast CCD visible imaging.The so-produced films were characterized by composition,thickness,roughness,wetting ability,and morphology.When compared to the MoS_(2)targets,they show a slight decrease of S with respect to Mo,due to higher ablation yield,low fusion temperature and high sublimation in vacuum.The pulsed IR laser deposited Mo Sx(with 1laser-deposited Mo Sx films are also presented and discussed.

关键词： MoS_(2) laser ablation plasma ion acceleration quadrupole mass spectrometry PLD

Enhanced ablation efficiency for silicon by femtosecond laser microprocessing with GHz bursts in MHz bursts(BiBurst)

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International Journal of Extreme Manufacturing 2022年第1期4卷 75-83页

作者： Francesc Caballero-Lucas Kotaro Obata Koji Sugioka RIKEN Center for Advanced Photonics 2-1 HirosawaWako-shiSaitama 351-0198Japan

Ultrashort laser pulses confine material processing to the laser-irradiated area by suppressing heat diffusion,resulting in precise ablation in diverse materials.However,challenges occur when high speed material removal and higher ablation efficiencies are required.Ultrafast burst mode laser ablation has been proposed as a successful method to overcome these limitations.Following this approach,we studied the influence of combining GHz bursts in MHz bursts,known as Bi Burst mode,on ablation efficiency of silicon.Bi Burst mode used in this study consists of multiple bursts happening at a repetition rate of 64 MHz,each of which contains multiple pulses with a repetition rate of 5 GHz.The obtained results show differences between Bi Burst mode and conventional single pulse mode laser ablation,with a remarkable increase in ablation efficiency for the Bi Burst mode,which under optimal conditions can ablate a volume4.5 times larger than the single pulse mode ablation while delivering the same total energy in the process.

关键词： BiBurst mode GHz burst laser ablation surface microfabrication

SS-LASS Zircon Dating Deciphering Multiple Episodes of Anatexis in a Deeply-Subducted Continental Crust:An Example from Sulu Orogen,China

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Journal of Earth Science 2024年第1期35卷 85-98页

作者： Peng Feng Lu Wang Xiawen Li Wenjie Ding Zhe Chen School of Resource&Environment and Safety Engineering University of South ChinaHengyang 421001China State Key Laboratory of Geological Processes and Mineral Resources Center for Global TectonicsSchool of Earth SciencesChina University of GeosciencesWuhan 430074China No.8 Institute of Geology and Mineral Resources Exploration of Shandong Province Rizhao 276826China

‘Single shot'laser-ablation split-stream(SS-LASS)technique analyzing unpolished zircon grains makes their thin rims tenable for determination,which thus offers great potential in deciphering the timing of multiple and short-lived episodes of anatexis and metamorphism in deeplysubducted continental crusts.Dominated granitic gneisses in the deeply subducted continental crust undergoing considerable fluid-melt activities persist multistage growth of zircon.Therefore,a comparative study of SS-LASS and laser ablation inductively coupled plasma mass spectrometer(LA-ICP-MS)zircon dating was conducted on the granitic gneisses from the Sulu belt in this study.Zircons mostly show a core-mantle-rim structure with CL-bright rims thinner than 5μm.For LA-ICP-MS dating,relict magmatic zircon cores yield protolith ages of ca.756-747 Ma;whereas the dark mantles record synexhumation anatexis at ca.214 Ma.By contrast,according to the U-Pb dates,trace element features,zircon crystallization temperatures and geological context,SS-LASS zircon petrochronology deciphers three episodes of anatectic events,as follows:(i)the first episode of anatexis at ca.218-217 Ma dominated by phengite-breakdown melting,likely facilitating the exhumation of the UHP slice from mantle depth;(ii)the second episode of anatexis at ca.193–191 Ma indicating part of northern Dabie-Sulu belt was still“hot”because of buried in the thickened orogenic crust at that time;(iii)the third episode of anatexis(ca.162–161 Ma)consistent with the intrusion ages(ca.161–141 Ma)of the Jurassic to Cretaceous granitoids in this orogen,suggesting the initial collapse of the orogenic root of the Sulu belt occurred at Late Jurassic due to the Izanagi plate initially subducting beneath the margin of Eastern Asia.This study sheds new light upon the utilization of SS-LASS petrochronology deciphering multiple anatectic events in the deeply-subducted continental crust and supports us in better understanding the tectonic evolution of Dabie-Sulu Orogen.

关键词： anatexis laser ablation laser-ablation split-stream ultrahigh-pressure metamorphic belt Sulu Orogen

GHz bursts in MHz burst(BiBurst) enabling high-speed femtosecond laser ablation of silicon due to prevention of air ionization

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International Journal of Extreme Manufacturing 2023年第2期5卷 208-214页

作者： Kotaro Obata Francesc Caballero-Lucas Shota Kawabata Godai Miyaji Koji Sugioka RIKEN Center for Advanced Photonics 2-1 HirosawaWako-shiSaitama 351-0198Japan Department of Applied Physics Tokyo University of Agriculture and Technology2-24-16 NakachoKoganeiTokyo 184-8588Japan

For the practical use of femtosecond laser ablation, inputs of higher laser intensity are preferred to attain high-throughput material removal. However, the use of higher laser intensities for increasing ablation rates can have detrimental effects on ablation quality due to excess heat generation and air ionization. This paper employs ablation using BiBurst femtosecond laser pulses, which consist of multiple bursts(2 and 5 bursts) at a repetition rate of 64 MHz, each containing multiple intra-pulses(2–20 pulses) at an ultrafast repetition rate of 4.88 GHz, to overcome these conflicting conditions. ablation of silicon substrates using the BiBurst mode with 5 burst pulses and 20 intra-pulses successfully prevents air breakdown at packet energies higher than the pulse energy inducing the air ionization by the conventional femtosecond laser pulse irradiation(single-pulse mode). As a result, ablation speed can be enhanced by a factor of23 without deteriorating the ablation quality compared to that by the single-pulse mode ablation under the conditions where the air ionization is avoided.

关键词： BiBurst mode GHz burst laser ablation silicon air ionization