- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Relating fracture toughness to micro-pillar compression response for a laser powder bed additive manufactured bulk metallic glass
摘要： A Zr-based bulk metallic glass produced using selective laser melting (SLM) was compared to the same alloy fabricated using traditional suction-casting. Analysis of the fracture toughness and mechanism through single edge notched beam bending experiments show a significantly reduced damage tolerance for the laser-processed material (KQ ~ 138.0 ± 13.1 → 28.7 ± 3.7 MPa √m), even though X-ray diffraction and microhardness responses were identical. Uncovered here using uniaxial quasistatic micro-pillar compression, as-cast samples more readily undergo shear transformations (evidenced through discrete load drops) below the nominal 0.2% yield stress, which can be connected to the higher macroscopic toughness. Differential scanning calorimetry demonstrated that the increased barrier to shear transformation for the SLM material could not be explained by the relative relaxation states. Rather, it is attributed to the greater dissolved oxygen concentration in the laser-processed material, which is postulated to decrease atomic mobility in the structure and thereby increase the activation energy required to initiate shear transformations.
关键词： fracture toughness,metallic glass,amorphous materials,additive manufacturing,selective laser melting,micromechanics
更新于2025-09-19 17:13:59
-
Amplified spontaneous emission and random lasing using CsPbBr3 quantum dots glass through controlling crystallization
摘要： By increasing the heat treatment temperature, the average size of CsPbBr3 quantum dots (QDs) in the glass matrix was increased, which contribute to the 5.5 folds increase of the optical gain coefficients. And the corresponding lasing threshold can decrease from 0.752 mJ/cm2 to 0.138 mJ/cm2.
关键词： CsPbBr3 quantum dots,glass matrix,heat treatment temperature,optical gain coefficients,lasing threshold
更新于2025-09-19 17:13:59
-
The effect of short glass fibers on the process behavior of polyamide 12 during selective laser beam melting
摘要： In additive manufacturing, polymer composites are used for setting tailored properties. Short glass fibers can be used as fillers for polyamide 12 for enhancing stiffness or tensile strength as well as for reducing shrinkage. In this paper, the effects of short glass fibers on polyamide 12 concerning powder properties, process behavior and part properties in laser beam melting of polymers (SLS) are investigated. It could be shown that by increasing the short glass fiber content powder properties as well as part properties are immensely affected. By adding glass fibers, powder properties, like flowability and diffuse reflection decrease. The isothermal crystallization changes resulting in a narrower processing window. Concerning mechanical properties, short glass fibers allow for a higher stiffness until a critical limit of filler concentration within this study is reached, after which the tensile strength decreases. The elongation of break decreases by rising the filler content.
关键词： Additive manufacturing,Short glass fibers,PA 12,Selective laser sintering,Filled systems
更新于2025-09-19 17:13:59
-
Groove Formation in Glass Substrate by a UV Nanosecond Laser
摘要： This study reports the laser grooving of glass. In this study, an ultraviolet (UV) nanosecond laser is used to produce grooves in soda lime glass by varying laser power, scan speed, pulse repetition rate, and number of scans. The threshold power density to generate damage on glass surface is found to be ~6.37 × 108 W/cm2. According to the result of a single laser scan, at a high laser power and low scan speed, material removal does not nearly occur, and only volume melting underneath the glass surface and large thermal crack are induced. With the decreasing laser power and increasing scan speed, a groove with a smooth surface is formed owing to the melting-dominant material removal process. The groove of rough surface morphology is produced with the further increase of the scan speed due to shattering induced by shock wave. Under this condition, it is found that either small cracks are produced or a crack-free groove is obtained. In this study, the fabrication of the microchannel for bio-chip application is also attempted by multiple laser scans. The near rectangular-shaped and crack-free groove (width × depth: ~220 μm × ~500 μm) with quite a smooth surface is fabricated by the multiple laser scans with a non-zero scan spacing.
关键词： ultra violet (UV),laser grooving,nanosecond laser,glass,groove
更新于2025-09-19 17:13:59
-
Three-Dimensional Laser Printing of Macro-Scale Glass Objects at a Micro-Scale Resolution
摘要： Three-dimensional (3D) printing has allowed for the production of geometrically complex 3D objects with extreme flexibility, which is currently undergoing rapid expansion in terms of materials, functionalities, as well as areas of application. When attempting to print 3D microstructures in glass, femtosecond laser-induced chemical etching (FLICE)—which is a subtractive 3D printing technique—has proved itself a powerful approach. Here, we demonstrate the fabrication of macro-scale 3D glass objects of large heights up to ~3.8 cm with an identical lateral and longitudinal feature size of ~20 μm. The remarkable accomplishment is achieved by revealing an unexplored regime in the interaction of ultrafast laser pulses with fused silica, which results in depth-insensitive focusing of the laser pulses inside fused silica.
关键词： light-field manipulation,ultrafast laser microfabrication,3D glass printing
更新于2025-09-19 17:13:59
-
Component Regulation and Crystallization Mechanism of CsPbBr3/Cs4PbBr6 Perovskite Composite Quantum Dots-Embedded Borosilicate Glass for Light Emitting Application
摘要： Cesium lead bromide CsPbBr3/Cs4PbBr6 perovskite composite QDs-embedded borosilicate glass (QDs@glass) have been prepared by using the conventional melting-quenching and heat-treatment technique. The effect of raw components and melting condition on the crystallization process, phase transition and crystal growth of CsPbBr3/Cs4PbBr6 QDs in the glass matrix were discussed in details. The formation of Cs4PbBr6 in glass has a significant impact on the optical properties of CsPbBr3 QDs. Excellent QDs@glass with high photoluminescence quantum yield (PLQY) of ～58% was achieved by optimizing the raw components and melting condition. The obtained QDs@glass shows outstanding thermal stability, photostability and water resistance stability. The PL intensity of QDs@glass remains 80% of the original one after being stored in a chamber with high-temperature and high-humidity (85 °C/RH 85%) for 70 hours, and shows little decrease (2%) after being soaked into deionized water for 70 hours. The white LED fabricated by using the as-synthesized green QDs@glass powder and red K2SiF6: Mn4+ phosphor on the surface of a blue LED chip displays luminous efficiency of 25 lm/W with CIE coordinates of (0.3328, 0.3442) at 100 mA and exhibits a wide color gamut (130% of the National Television System Committee standard).
关键词： Quantum dots,Borosilicate glass,White LED,Display,Cesium lead bromide
更新于2025-09-19 17:13:59
-
Laser-induced damage of black glass before and after surface treatment by containing impurities-SiO2 film during ultra clean manufacturing
摘要： Ultra-clean manufacturing is an indispensable key technology for inertial confinement fusion (ICF) to generate clean and sustainable energy, but the pollutants from laser-induced damage are a threat to ultra-clean manufacturing. Here we investigate the damage of black glass in a high laser fluence system, which refers to high fluence laser beams in fusion class laser systems. Results show a significant dependence of damage parameters on the laser pulse duration at 355 nm before and after surface treatment by SiO2 films, which include the laser-induced damage threshold (LIDT), morphology and depth. The simulation indicates that the LIDT of SiO2 films on black glass is improved obviously, which is 14.1 J/cm2, while that of normal black glass is 10.2 J/cm2. The presence of impurities will aggravate the damage of the thin films and pollutes the laser system. LIDT of SiO2 films containing impurities is only 3.6 J/cm2. The experiments show that the average LIDT of black glass is 9.54 J/cm2 while that of thin films with impurities is no more than 4.12 J/cm2. These salient results provide a new concept for the protection of absorbing stray light for ultra-clean manufacturing.
关键词： Black glass,Sustainable energy,Impurities,Ultra-clean manufacturing,LIDT
更新于2025-09-19 17:13:59
-
Photovoltaic activity of electrodes based on intact photosystem I electrodeposited on bare conducting glass
摘要： We demonstrate photovoltaic activity of electrodes composed of fluorine-doped tin oxide (FTO) conducting glass and a multilayer of trimeric photosystem I (PSI) from cyanobacterium Synechocystis sp. PCC 6803 yielding, at open circuit potential (OCP) of + 100 mV (vs. SHE), internal quantum efficiency of (0.37 ± 0.11)% and photocurrent density of up to (0.5 ± 0.1) μA/cm2. The photocurrent measured for OCP is of cathodic nature meaning that preferentially the electrons are injected from the conducting layer of the FTO glass to the photooxidized PSI primary electron donor, P700+, and further transferred from the photoreduced final electron acceptor of PSI, Fb, via ascorbate electrolyte to the counter electrode. This observation is consistent with preferential donor-side orientation of PSI on FTO imposed by applied electrodeposition. However, by applying high-positive bias (+ 620 mV) to the PSI-FTO electrode, exceeding redox midpoint potential of P700 (+ 450 mV), the photocurrent reverses its orientation and becomes anodic. This is explained by “switching off” the natural photoactivity of PSI particles (by the electrochemical oxidation of P700 to P700+) and “switching on” the anodic photocurrent from PSI antenna Chls prone to photooxidation at high potentials. The efficient control of the P700 redox state (P700 or P700+) by external bias applied to the PSI-FTO electrodes was evidenced by ultrafast transient absorption spectroscopy. The advantage of the presented system is its structural simplicity together with in situ-proven high intactness of the PSI particles.
关键词： Photoelectrochemical measurements,Cyanobacterium Synechocystis sp. PCC 6803,Femtosecond-transient absorption,Photovoltaics,FTO conducting glass,Photosystem I
更新于2025-09-19 17:13:59
-
Additive Manufacturing of Three-dimensional Metal-glass Functionally Gradient Material Components by Laser Powder Bed Fusion with In situ Powder Mixing
摘要： Existing commercial three-dimensional (3D) printing systems based on powder bed fusion approach can normally only print a single material in each component. In this paper, functionally gradient materials (FGM) with composition variation from a copper alloy to a soda-lime glass were manufactured using a proprietary nozzle-based multi-material selective laser melting (MMSLM) system. An in situ powder mixing system was designed to mix both metal and glass powders at selective ratios and the mixed powders were dispensed with an ultrasonic vibration powder feeding system with multiple nozzles. From the cross section analysis of the gradient structures, glass proportion increased gradually from the metallic matrix composite (MMC), transition phase to ceramic matrix composite (CMC). The pure copper alloy joined the MMC part and the pure glass phase penetrated into the CMC part during laser processing, which anchored the glass phase, as the main mechanism of combining pure metal and pure glass by FGM in 3D printed parts. From results of indentation, tensile and shear tests on the gradient material samples, it showed that mechanical properties of the FGM gradually changed from ductility (metal side) to brittle (glass side). The weakest part of the FGM structure occurred at the interface between transition phase and the CMC, which was also the interface between the ductile and brittle phases.
关键词： copper-glass,Powder Bed Fusion,horizontal gradient structure,multi-material selective laser melting,functionally gradient materials
更新于2025-09-19 17:13:59
-
Spatial tailoring of the refractive index in infrared glass-ceramic films enabled by direct laser writing
摘要： The development of infrared gradient refractive index (GRIN) components relies on the ability to modify the refractive index and dispersion properties of suitable host materials with a high spatial selectivity and a sufficient magnitude of change. We present a novel multi-step approach to induce local refractive index changes in chalcogenide optical materials. Films with thicknesses between 1 and 40 μm fabricated from multi-component GeSe2-As2Se3-PbSe (GAP–Se) glass-ceramic materials were irradiated with continuous-wave and nanosecond-pulsed laser light, and post-processed with heat-treatments. A maximum local refractive index change of Δn = 0.088 across a broad spectral range in the infrared was realized. Spatial control of the refractive index variation was achieved through thermally-induced crystallization of a Pb-rich crystal phase. The magnitude of the index change scaled with the laser power and the exposure dose while the material maintained the required optical quality. The material performance validated in this study for thick films (20–40 μm films) reconfirms our ability to extend results from thin GAP-Se films towards novel optical designs.
关键词： Direct laser writing,Chalcogenide glass,Photo-thermal process,Gradient refractive index
更新于2025-09-19 17:13:59