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oe1(光电查) - 科学论文

50 条数据
?? 中文(中国)
  • Investigation of cut quality in fiber laser cutting of CFRP

    摘要: Fiber laser cutting of CFRP sheets was investigated using a 2 kW multi-mode fiber laser, focusing on how the cut quality factors, such as kerf width, kerf depth, matrix evaporation width, matrix recession width, kerf taper angle, matrix damage zone, and cut surface morphology, change as laser power, laser scanning speed, and the number of laser passes are varied. By designing a systematic experiment on a large process window, several important parameters for kerf width, kerf depth, matrix evaporation width, and matrix recession width were identified, and using them, it was verified that the beam scanning speed is a dominant factor for minimizing thermal damages. Also, circular rings were observed in each carbon fiber at the cut surfaces, and it looked as if they were generated when each fiber was thermally fused in the radial direction. A larger number of laser passes was found to contribute to a smooth surface morphology, because of the formation of highly-fused surfaces, which prevents fiber delamination and pull-outs. Optimum process conditions were also identified by comparing various cut quality factors.

    关键词: Fiber laser cutting,Optimal process conditions,Cut quality factors,Thermal damage,Carbon fiber reinforced plastic (CFRP)

    更新于2025-11-28 14:24:20

  • Parametric study of laser cutting of carbon fibre reinforced polymer (CFRP) and the effect of fibre orientation on cutting quality

    摘要: Laser cutting of CFRP was performed using 2 kW fibre laser. A detailed analysis of the effect of various laser processing parameters on the cutting of CFRP was carried out. The present work considers mainly laser power (W), scan speed (mm/min), gas pressure (bar) and duty cycle (%) as the process parameters with average kerf width and heat affected zone (HAZ) as the output parameters. Cutting of the fibres at 90o with respect to fibre orientation was performed. The SEM and EDS analysis were also performed to understand the cut quality, matrix melting, fibre pullout and vaporisation phenomena of the matrix in the heat affected zone (HAZ). Laser cutting of CFRP with a minimum kerf width of around 184 μm was observed for 800 W, 600 mm/min, 3 bar and 25% duty cycle while HAZ in this parameter was around 1561 μm. Kerf width and HAZ directly increase with an increase in laser power, gas pressure and duty cycle, but they reduce with increase in scan speed. SEM images confirm that the CFRP cutting process generates relatively burr-free fibre edges. Matrix recession and delamination (fibre pullout) were identified as the major quality defects occurring in the laser cutting process of CFRP.

    关键词: fibre delamination,matrix melting,heat affected zone,laser cutting,fibre consolidation,kerf width,CFRP

    更新于2025-11-28 14:24:20

  • Effect of nozzle types on the laser cutting performance for 60-mm-thick stainless steel

    摘要: The laser cutting of 60-mm-thick stainless steel using a 6-kW ?ber laser was performed to investigate the e?ect of the geometric nozzle con?guration on the operating tolerance of the stand-o? distance. The stand-o? distance is the distance between the nozzle tip and the top surface of the steel plate. Two types of nozzles—a subsonic nozzle with a convergent geometry and a supersonic nozzle with a convergent-divergent geometry—were used to comparatively evaluate the ?ow behavior through interferometric analysis. A laser cutting experiment was conducted in accordance with the interferometric analysis, focusing on the stand-o? distance variation. The stand-o? distance was varied from 1 to 60 mm in consideration of the melt-removal capability of the applied cutting nozzles. The throat diameters of the nozzles were 2 and 3 mm. According to the results, the supersonic nozzle has a better operating tolerance of the stand-o? distance for the laser cutting of 60-mm-thick stainless steel.

    关键词: Laser cutting,Supersonic nozzle,Nomarski interferometer

    更新于2025-11-28 14:24:20

  • A laser-cutting-based manufacturing process for the generation of three-dimensional scaffolds for tissue engineering using Polycaprolactone/Hydroxyapatite composite polymer

    摘要: A manufacturing process for sheet-based stacked scaffolds (SSCs) based on laser-cutting (LC) was developed. The sheets consist of Polycaprolactone/Hydroxyapatite (PCL/HA) composite material. Single sheets were cut from a PCL/HA foil and stacked to scaffolds with interconnecting pores of defined sizes. HA quantities up to 50% were processable with high reproducibility, while the accuracy was dependent on the applied laser power. The smallest achievable pore sizes were about 40 μm, while the smallest stable solid structures were about 125 μm. The human mesenchymal stem cell line SCP-1 was cultured on the manufactured PCL/HA scaffolds. The cells developed a natural morphology and were able to differentiate to functional osteoblasts. The generation of PCL/HA SSCs via LC offers new possibilities for tissue engineering (TE) approaches. It is reliable and fast, with high resolution. The SSC approach allows for facile cell seeding and analysis of cell fate within the three-dimensional cell culture, thus allowing for the generation of functional tissue constructs.

    关键词: laser-cutting,Tissue engineering,scaffold

    更新于2025-11-21 11:24:58

  • Keyhole cutting of carbon fiber reinforced polymer using a long-duration nanosecond pulse laser

    摘要: The machining performance of a high-energy nanosecond pulse laser with a near-infrared wavelength is investigated for carbon fiber-reinforced polymer (CFRP) with two different fiber arrangements. This research work demonstrates for the first time that a keyhole mode cutting can be achieved for CFRP materials using a high-energy nanosecond pulse laser of a Long Pulse mode (120 ns). Specifically, it is shown that the short-duration Q-Switch mode (8 ns) results in ineffective material removal for CFRP, despite much higher peak laser power intensity than the Long Pulse mode. In Long Pulse mode, multi-pass straight line and contour cutting experiments are further performed to investigate the effect of laser processing parameters and resultant machined surface integrity. Plasma absorption effects using both pulse modes are discussed. The results show that a 2.2 mm thick cross-ply CFRP panel can be cut through using as few as 6 laser passes, and a high-quality machined surface can be produced with a limited heat-affected zone and minimal fiber pull-out using Argon assist gas. The successful outcomes from this work provide the key to enable efficient CFRP laser machining using high-energy nanosecond pulse lasers, and offer insight into the unique energy absorption mechanisms for CFRP laser machining.

    关键词: Laser cutting,Keyhole,Long pulse,Nanosecond pulse laser,Carbon fiber reinforced polymer

    更新于2025-11-21 11:08:12

  • Soft tissue cutting efficiency by 980?nm laser with carbon-, erbium-, and titanium-doped optothermal fiber converters

    摘要: Objectives: The use of near-IR diode lasers for contact soft tissue surgery is attended by a risk of severe thermal damage of surrounding tissues due to the low cutting efficiency of these lasers. To increase the cutting efficiency tips of a near-IR lasers in contact surgery special (converters) which transform laser light to heat are used. The present in vivo study evaluated temperature dynamics and soft tissue cutting efficiency of 980 nm diode laser equipped with standard carbon- and novel erbium- and titanium-doped converters. Materials and Methods: For in vitro treatment on soft tissue (chicken thigh), 980 nm diode laser was used. The radiation was delivered to the tissue by a quartz fiber with a core diameter of 400 ± 5 mm. The carbon-, erbium-, or titanium-doped converters were mounted at the fiber distal end. The converters temperature was measured by IR-sensor integrated into the laser radiation delivery system. The temperature dynamics of each converter during soft tissue treatment was evaluated. The converter was in contact with the soft tissue surface and moved across the surface of soft tissue with a speed of 1, 3, or 6 mm/s. The average power of laser radiation was 0.3, 1.0, or 4.0 W. The collateral thermal damage of treated soft tissues was evaluated using NTBC stain. The width and depth of coagulation and ablation zones of laser wounds was determined. The soft tissue cutting efficiency with different converters was calculated. Results: The cutting efficiency, collateral damage, and converter temperature in contact with soft tissue change depending on the type of converter, the power of laser radiation and the converter movement speed along the temperature tissue (1,980 ± 154 °C), at which a tissue cut takes place, was fixed for Ti-doped converter for laser power of 4.0 W and movement speed of 1 mm/s. Minimal converter temperature (540 ± 30 °C), at which a tissue cut takes place, was fixed for Ti-doped converter for laser power of 1.0 W and movement speed of 6 mm/s. Maximal depth of coagulation (0.72 ± 0.10 mm) was fixed for Ti-doped converter for laser power of 4.0 W and movement speed of 1 mm/s. Minimal depth of coagulation (0.11 ± 0.02 mm) was fixed for C-doped converter for laser power of 0.3 W and movement speed of 3 mm/s. Maximal cutting efficiency (0.57 mm3/W) was fixed for Er-doped converter for laser power of 1.0 W and movement speed of 1 mm/s. Minimal cutting efficiency (0.02 mm3/W) was fixed for C-doped converter for laser power of 4.0 W and movement speed of 6 mm/s. Conclusion: All three studied types of converters can be used for contact surgery of soft tissues by 980 nm diode laser. Er-doped and Ti-doped converters are more resistant to laser heating then C-doped converter, they dissect soft tissue more effectively. This will also expand the potential of everyday routine clinical procedures, making them safer, faster, and easier. These converters can be used in general surgery, plastic surgery, dermatology, angioplasty, dentistry, neurosurgery, etc. Lasers Surg. Med. 9999:1–16, 2018. ? 2018 Wiley Periodicals, Inc.

    关键词: soft tissue,coagulation,surgery,efficiency,IR-sensor,diode laser,cutting,converter,fiber

    更新于2025-10-24 16:41:07

  • Optimisation of edge quality on stainless steel 316L using low power fibre laser beam machining

    摘要: In the manufacturing industry critical importance lies upon the dimensional accuracy of a machining part especially for precision assembly operation in sheet metal cutting. But the converging diverging shape of the laser beam profile causes the existence of kerf taper in laser cut specimen. Use of low power fibre laser beam machining in the order of 50 watt makes it extremely difficult to perform good quality cut on stainless steel sheet metal. Cutting wedge angle, a relatively uncommon process variable performs a critical role for the determination of unevenness in kerf characteristic. Cutting result of kerf taper with a 50-watt fibre laser is presented in this investigation. The purpose of the investigation is to reveal the ability of the low power fibre laser to cut stainless steel AISI 316 L with 1 mm thickness. The effect of the cutting wedge angle and other process variables like power, duty cycle, pulse frequency and scanning speed has been analysed through an application of Response Surface Methodology (RSM) with CCD technique. Validation of experiments on the proposed model reveals that adjustment of proper process parameters can optimise the required edge quality.

    关键词: Laser cutting,response surface methodology,kerf taper,cutting wedge angle,AISI 316 L stainless steel

    更新于2025-09-23 15:21:01

  • [Laser Institute of America ICALEO?? 2014: 33rd International Congress on Laser Materials Processing, Laser Microprocessing and Nanomanufacturing - San Diego, California, USA (October 19a??23, 2014)] International Congress on Applications of Lasers & Electro-Optics - Optimisation of underwater laser cutting for decommissioning purposes

    摘要: In both the nuclear and offshore sectors, there are many potential applications for underwater cutting. Although underwater cutting using lasers was demonstrated many years ago, the limitations imposed at that time by the 10 micron laser beam wavelength available, meant realisation of underwater laser cutting was almost impossible. With the advent of fibre delivered laser power this situation has changed. This paper will describe recent work using a 5kW Yb fibre laser source, equipped with a specially designed process head for underwater laser cutting. Results will be presented for cutting both 304 stainless and C-Mn (S275JR) steel, at thicknesses of up to 32mm. The paper will also describe the various parameters thought to be important in underwater cutting and their effects on the cut achieved. It will be shown that for different applications, different sets of parameters can be used to achieve different results. As an example of this, in the application of nuclear decommissioning, for maximising dross height on the parts being cut will be described. In nuclear decommissioning, maximising the dross adhesion is important, as it means less radioactive material from the kerf is released into the water and therefore more remains on the parts being size reduced for future long term storage.

    关键词: underwater laser cutting,decommissioning,dross height,nuclear,offshore,mass reduction,fibre laser

    更新于2025-09-23 15:21:01

  • Deep and high precision cutting of alumina ceramics by picosecond laser

    摘要: Ceramics possess high thermal and chemical resistance, low density, and high compressive strength; however, the machining complications imposed by their inherent brittleness limit their range of applications. Laser cutting technology can offer an automated manufacturing technique for machining these brittle materials. In this paper, a laser cutting method, so-called wobbling, was developed for performing deep, high precision, and defect-free laser cutting of industrial grade alumina ceramics. This work explored picosecond laser process parameters such as focal position, linear speed, and wobble amplitude in order to control cut depth and optimize cut quality in terms of kerf width, kerf taper, surface cleanness, while avoiding crack formation. The morphology and cut quality were evaluated using 3D laser scanning microscopy and scanning electron microscopy (SEM). Picosecond laser cutting process parameters were optimized, achieving a maximum material removal rate of ~10 mm3/min. It was shown that the laser cutting process developed via these experiments represents an effective and efficient manufacturing tool that can be incorporated in engineered net shaping systems.

    关键词: Laser cutting,Material removal rate,Ablation,Ultrafast laser micromachining,Alumina ceramics

    更新于2025-09-23 15:21:01

  • Solving the Laser Cutting Path Problem Using Population-Based Simulated Annealing with Adaptive Large Neighborhood Search

    摘要: This paper presents an alternative algorithm for solving the laser cutting path problem which was modeled as Generalized Traveling Salesman Problem (GTSP). The objective is to minimize the traveling distance of laser cutting of all profiles in a given layout, where a laser beam makes a single visit and then does the complete cut of individual profile in an optimum sequence. This study proposed a hybrid method combining population-based simulated annealing (SA) with an adaptive large neighborhood search (ALNS) algorithm to solve the cutting path problem. Recombination procedures were executed alternately using swap, reversion, insertion and removal-insertion through a fitness proportionate selection mechanism. In order to reduce the computing time and maintain the solution quality, the 35% proportion of population were executed in each iteration using the cultural algorithm selection method. The results revealed that the algorithm can solve several ranges of problem size with an acceptable percentage of error compared to the best known solution.

    关键词: ALNS,GTSP,Laser cutting path,Cultural algorithm,Simulated annealing

    更新于2025-09-23 15:21:01