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Variation of Surface Topography in Laser Powder Bed Fusion Additive Manufacturing of Nickel Super Alloy 625
摘要： This document provides details on the files available for download in the dataset “Variation of Surface Topography in Laser Powder Bed Fusion of Nickel Super Alloy 625.” The following sections provide details on the experiments, methods, and data files. The experiment detailed in this document methodically varies part position and surface orientation relative to the build plate and relative to the recoater blade. This dataset provides surface height data for analysis and development of correlations by the greater research community.
关键词： additive manufacturing,focus variation,IN625,surface texture,surface topography,nickel super alloy 625,laser powder bed fusion
更新于2025-09-11 14:15:04
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MICRO WAVE PATTERNS BY VIBRATING-LENS ASSISTED LASER MACHINING
摘要： Surfaces with superimposed patterns offer, in many applications, numerous advantages over traditional smooth surfaces since they profoundly affect functional behavior, e.g., friction, wettability, etc. Different shapes and sizes of surface patterns were fabricated by traditional laser machining, however, micro wave patterns are difficult to generate by this process. In this paper, vibrating-lens assisted laser machining is proposed to generate such patterns and to extend its capabilities. A model, based on the traditional heat-flow principle, was built to ascertain the energy distribution in the process and predict the shape of the wavy patterns generated. A specially developed experimental setup was used for model validation. Sinusoidal wave patterns were analyzed as an example to demonstrate geometrical feature under different parameters and the feasibility of the process. The feasibility of the proposed theoretical and experimental methodologies was illustrated through a comparative analysis of experimental and simulation scenarios.
关键词： Pattern simulation,Surface topography,Vibrating-lens,Laser machining,Traditional heat-flow principle
更新于2025-09-11 14:15:04
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Femtosecond laser microstructuring of alumina toughened zirconia for surface functionalization of dental implants
摘要： The continuous need for high-performance implants that can withstand mechanical loads while promoting implant integration into bone has focused recent research on the surface modification of hard ceramics. Their properties of biocompatibility, high mechanical and fatigue resistance and aesthetic color have contributed to its successful applications in dentistry. Alumina toughened Zirconia (ATZ) has been gaining attention as a material for dental implants applications due to its advanced mechanical properties and minimal degradation at body temperature. Still, in order to improve tissue response to this bioinert material, additional modifications are desirable. Improving the surface functionality of this ceramic could lead to enhanced implant-tissue interaction and subsequently, a successful implant integration. In this work, microtopographies were developed on the surface of Alumina toughened Zirconia using an ultrafast laser methodology, aiming at improving the cellular response to this ceramic. Microscale grooves and grid-like geometries were produced on ATZ ceramics by femtosecond laser ablation, with a pulse width of 150 fs, wavelength of 800 nm and repetition rate of 1 kHz. The variation of surface topography, roughness, chemistry and wettability with different laser processing parameters was examined. Cell-surface interactions were evaluated for 7 days on both microstructured surfaces and a non-treated control with pre-osteoblasts, MC3T3-E1 cells. Both surface topographies showed to improve cell response, with increased metabolic activity when compared to the untreated control and modulating cell morphology up to 7 days. The obtained results suggest that femtosecond laser texturing may be a suitable non-contact methodology for creating tunable micro-scale surface topography on ATZ ceramics to enhance the biological response.
关键词： Femtosecond laser microtexturing,Dental implants,Hard ceramics,Alumina toughened zirconia,Surface topography,Biological response
更新于2025-09-11 14:15:04
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Accuracy of 3D surface scanners for clinical torso and spinal deformity assessment
摘要： Externally visible deformities are cosmetic features of great concern for Adolescent Idiopathic Scoliosis (AIS) patients. Current assessment techniques for AIS do not fully encompass the external deformity. A non-invasive method capable of capturing superficial anatomy, such as 3D scanning, would enable better qualitative and quantitative evaluation of cosmesis. This study aimed to quantify the accuracy of commonly available scanners, in assessing posterior asymmetry in AIS. The technique of 3D surface deviation analysis was proposed as a suitable method for comparing the models created by each scanner. Eight plaster cast moulds manufactured to create braces for AIS patients were used as test samples. Four 3D scanners were selected: Solutionix RexScan CS + ; Artec Eva; Microsoft Kinect V1; iPhone with 123D Catch App. These scanners were selected from those available as representative of a range of scanning technologies. Each cast was scanned and 3D models created. A simulated rib hump measurement was obtained and the surface-to-surface deviations between the Solutionix scan and all other scans were determined. The Solutionix scanner is a metrology scanner of very high quality and so it was selected as the reference. Surface-to-surface deviations were calculated in the positive and negative directions separately to specifically identify size and volume inaccuracies created by the scans. Surface deviations showed excellent agreement between the Solutionix and the Eva with deviations of + 0.17 ± 0.17 mm (Eva regions larger) and ?0.20 ± 0.32 mm (Eva regions smaller) (mean ±SD). The Kinect showed lower agreement ( + 1.58 ± 1.50 mm and ?0.58 ± 0.58 mm). The iPhone scans were not able to be scaled to the correct size, so were excluded. Rib hump measurements with all scanners were within clinical measurement variability ( ±4.9 deg) of the known values. These commercially available 3D scanners are capable of imaging torso shape in 3D and deriving clinically relevant external deformity measures. The non-invasive 3D topographic information provided can be used to improve assessment of torso shape in spinal deformity patients.
关键词： Torso Deformity,3D Scanning,Scoliosis,Accuracy,Reproducibility of results,Surface topography,Surface Deviations
更新于2025-09-10 09:29:36
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Role of Cerium Doping on Epitaxial Yttrium Iron Garnet Thin films
摘要： The present work discusses the growth optimization and magnetic properties of the Cerium doped Yttrium Iron Garnet (YIG) thin films grown through Pulsed Laser Deposition technique. The X-ray diffraction (XRD) reveals the highly crystalline, Single Phase, nature of films and the Atomic Force Microscopy (AFM) shows the films are very smooth, with root mean square roughness of less than 1 nm. Thickness of the films as calculated from the X-ray reflectivity (XRR) was found to be around 17, 35, 52, 70 and 122 nm. The Magnetic measurement shows the increase in the Saturation Magnetization, in the cerium doped YIG, but as the growth time increases, we observed a decrease in magnetic Saturation. The decrease in saturation magnetization arises due to the formation of residual Ce2O phase in the longer grown films. Longitudinal Spin Seebeck Voltage signal was observed in the films and the Platinum (Pt) deposited over the Cerium doped YIG film showed no sign of Pt magnetization.
关键词： Microwave technology,Surface topography,Cerium,Helmholtz coil
更新于2025-09-10 09:29:36
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Effects of N2 and NH3 plasma exposure on the surface topography of p-GaN under quasi-atmospheric pressure
摘要： We used atomic force microscopy to characterize the surface topography of p-GaN exposed to N2 and NH3 plasma under quasi-atmospheric pressure using a microwave-excited plasma source with a microstrip line structure. The exposure time was varied from 2 to 20 min at a substrate temperature of 700 °C. Under both N2 and NH3 plasma exposure for 2 min, the ridge-shaped features on the surface of as-grown p-GaN dulled immediately and the surface roughness decreased remarkably, whereas the atomic step structure of the surface was maintained. The step crossing and bunching of the surface disappeared with increasing exposure time to both types of plasma. However, increasing the NH3 plasma exposure time to 20 min led to the formation of pits and appearance of particles along the step edges, resulting in drastic roughening of the surface. Thus, GaN surfaces can be smoothed without the destruction of their step structures via moderate plasma exposure under quasi-atmospheric pressure, and these plasma sources could prospectively be used in metal-organic chemical vapor deposition systems for nitride semiconductor growth.
关键词： microwave-assisted plasma,surface topography,N2 and NH3 plasma,atomic force microscopy,metal organic chemical vapor deposition,GaN
更新于2025-09-09 09:28:46
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Dynamically evolving surface patterns through light-triggered wrinkling erasure
摘要： For many applications, it is an imperative that changes in polymer surface topography, especially periodic patterns, can be triggered on command by a well-defined remote signal. In this contribution, we report a light-induced cascade of changes in wrinkling wavelengths on thin polymer layers supported by an elastomeric substrate under tensile stress. Through the applied supramolecular design, the effect of varying the ratio of light active and light passive components can be easily assessed, and it is shown that both the cascade type as well as the rate of the progress of the dynamic light-induced changes can be tuned by this ratio, as well as by the light intensity. Furthermore, for the reported phenomena to occur, nominally only every 20th polymer repeat unit needs to be occupied by a chromophore, which makes the conversion of the sub-nm photoisomerization reaction into 10 μm - scale changes of periodic surface patterns extremely efficient.
关键词： light-triggered wrinkling erasure,polymer surface topography,photoisomerization,supramolecular design,elastomeric substrate
更新于2025-09-04 15:30:14
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Optical Sectioning Microscopy For Multilayer Structure With Micro-Scale Air Gaps Measurement
摘要： In this letter, we propose a new method based on the optical sectioning microscopy to characterize the multilayer structure with micro-scale air gaps. With this technique, sinusoidal fringe patterns having a predefined shifted phase produced by digital micro-mirror devices are illuminated onto the sample. The contrast response curve (CRC) of the reflected patterns along the scanning direction is determined by the phase-shifting algorithm while the object is scanned through the focus of the microscope. The maximum contrast value of the CRC occurs at the position where the sample is on the focal plane. The peak positions of the CRC are extracted through the Gaussian fitting and then implemented to achieve the surface topography and gap thickness distribution. To suppress the noise influence caused by the environment fluctuations or other factors, the frequency domain analysis (FDA) has been introduced in this work. The simulations and experiments are conducted to verify the feasibility of this technique, demonstrating the potential to be applied in such fields as semiconductor and biochip, where the air gap may play crucial roles.
关键词： thickness measurement,microscopy,surface topography
更新于2025-09-04 15:30:14