- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Laser drilling of micro-holes in single crystal silicon, indium phosphide and indium antimonide using a continuous wave (CW) 1070 nm fibre laser with millisecond pulse widths
摘要： The laser micro-drilling of “thru” holes, also known as via holes, in Si, InP and InSb semiconductor wafers was studied using millisecond pulse lengths from an IPG Laser Model YLR-2000 CW multimode 2 kW Ytterbium Fibre Laser and a JK400 (400 W) fibre laser, both with 1070 nm wavelength. The flexibility of this laser wavelength and simple pulsing scheme were demonstrated for semiconductor substrates of narrow (InSb Eg 0.17 eV) and wide (InP Eg 1.35 eV)) room-temperature bandgap, Eg, with respect to the photon energy of 1.1 eV. Optical microscopy and cross-sectional analysis were used to quantify hole dimensions and the distribution of recast material for all wafers and, for silicon, any microcracking for both (100) and (111) single crystal surface Si wafer orientations. It was found that the thermal diffusivity was not a sufficient parameter for predicting the relative hole sizes for the Si, InP and InSb single crystal semiconductors studied. Detailed observations for Si showed that, between the threshold energies for surface melting and the irradiance for drilling a “thru” hole from the front surface to rear surface, there was a range of irradiances for which micro-cracking occurred near the hole circumference. The directionality and lengths of these microcracks were studied for the (100) and (111) orientations and possible mechanisms for formation were discussed, including the Griffith criterion for microcracks and the failure mechanism of fatigue usually applied to welding of metals. For Si, above the irradiance for formation of a thru-hole, few cracks were observed. Future work will compare similar observations and measurements in other narrow- and wide-bandgap semiconductor wafer substrates. We demonstrated one application of this laser micro-drilling process for the micro-fabrication of a thru hole precisely-located in the centre of a silicon-based atom chip which had been patterned using semiconductor lithographic techniques. The end-user application was a source of magneto-optically trapped (MOT) cold atoms of Rubidium (87Rb) for portable quantum sensing.
关键词： microcrack,InP,Si,Griffith criterion,pulse,atom chip,Ytterbium fibre laser,semiconductor material,Fibre laser,semiconductor wafer,laser drilling,silicon,magneto-optical trap,MOT,via hole,laser micro-drilling,cold atoms,InSb,thru hole
更新于2025-09-12 10:27:22
-
Prediction of quality characteristics of laser drilled holes using artificial intelligence techniques
摘要： Micro-drilling using lasers finds widespread industrial applications in aerospace, automobile, and bio-medical sectors for obtaining holes of precise geometric quality with crack-free surfaces. In order to achieve holes of desired quality on hard-to-machine materials in an economical manner, computational intelligence approaches are being used for accurate prediction of performance measures in drilling process. In the present study, pulsed millisecond Nd:YAG laser is used for micro drilling of titanium alloy and stainless steel under identical machining conditions by varying the process parameters such as current, pulse width, pulse frequency, and gas pressure at different levels. Artificial intelligence techniques such as adaptive neuro-fuzzy inference system (ANFIS) and multi gene genetic programming (MGGP) are used to predict the performance measures, e.g. circularity at entry and exit, heat affected zone, spatter area and taper. Seventy percent of the experimental data constitutes the training set whereas remaining thirty percent data is used as testing set. The results indicate that root mean square error (RMSE) for testing data set lies in the range of 8.17–24.17% and 4.04–18.34% for ANFIS model MGGP model, respectively, when drilling is carried out on titanium alloy work piece. Similarly, RMSE for testing data set lies in the range of 13.08–20.45% and 6.35–10.74% for ANFIS and MGGP model, respectively, for stainless steel work piece. Comparative analysis of both ANFIS and MGGP models suggests that MGGP predicts the performance measures in a superior manner in laser drilling operation and can be potentially applied for accurate prediction of machining output.
关键词： Laser drilling,ANFIS,Genetic programming,Stainless steel,Artificial intelligence,Ti6Al4V,Surface cracks
更新于2025-09-12 10:27:22
-
A Particle Strength Exchange Method for Metal Removal in Laser Drilling
摘要： A meshfree Particle Strength Exchange (PSE) method is developed for metal removal in a simplified laser drilling problem. To this end, the problem of transient state heat transfer is solved by exerting a static laser beam with a Gaussian intensity distribution, as the external heat source. The proposed PSE scheme is a fully Lagrangian approach, which is straightforward to implement as compared to alternative meshfree methods currently adopted in the state of the art. The performance of the PSE method in solving the heat transfer problem at hand is assessed through a case-study on single-pulse laser heating of a metal workpiece. The simulation results are finally verified against both numerical and experimental data available in the literature, demonstrating the suitability of the proposed approach in addressing the thermal issues of complex manufacturing processes.
关键词： Heat transfer,PSE,Meshfree methods,Laser drilling
更新于2025-09-12 10:27:22
-
Machining induced residual stresses in AlSi10Mg component produced by Laser Powder Bed Fusion (L-PBF)
摘要： The adoption of metal powder-based laser process (L-PBF) for industrial applications continues to widen, due to an increasing knowledge on additive processes and the availability of new systems for industrial production. The use of L-PBF processes requires a deeper investigation and comparison on mechanical properties of conventional and additive parts. For instance, metal parts produced by L-PBF could require additional machining operations, which alter the stress state of additive components. In this work, the effect of machining operations on the residual stress state of an AlSi10Mg component produced by L-PBF is investigated by means of the semi destructive hole-drilling method.
关键词： AlSi10Mg,Machining,Hole-drilling method,Residual stresses,Laser Powder Bed Fusion
更新于2025-09-12 10:27:22
-
Modelling the influence of laser drilled recast layer thickness on the fatigue performance of CMSX-4
摘要： This paper introduces a novel approach to fatigue life prediction modelling considering the laser drilling effect on film cooling holes of turbine vanes. The methodology proposed is based on a stress-life model such as the Basquin law and the introduction of manufacturing damage effect. The proposed empirical model gives a unique versatility compared to other stress-life models by considering surface damage such as the recast layer produced by the laser drilling process. The proposed empirical model has been thoroughly tested and validated using existing fatigue data. The statistical analysis shows that the proposed model is adequate for estimating the fatigue life of laser drilled specimens considering the recast layer thicknesses effect. The proposed model also can estimate the life of untested specimens even when only a small sample of fatigue data is available, thereby reducing the required testing data.
关键词： Fatigue life,recast layer,laser drilling,surface defects
更新于2025-09-12 10:27:22
-
Experimental study of Hole Taper in Laser Trepan Drilling of Nickel Based Super alloy Sheet
摘要： This research article reports the optimum laser drilling input parameter for getting minimum hole taper and experimentally investigates the behaviour of hole taper in selected laser drilling input parameters on Inconel -718 sheet. Inconel -718 is nickel based super alloy, has diverse application in the field of manufacturing industries, including aerospace, aircraft, automotive, medical equipments, food service equipments and many others. The material is well suited for applications requiring high strength in temperature ranges from cryogenic up to 1400°F. Inconel-718 also exhibits excellent tensile and impact strength. The conventional drilling process faces difficulties to drill quality and precise holes in advanced materials due to its better mechanical properties. Making geometrical better hole is major concerned with conventional drilling process. With the help of Laser drilling process, a geometrically and dimensionally improved hole may be produced. The geometry of hole can be made further better if operating the Laser system at optimum parameters level. In this paper the effects of laser input parameters on hole taper have been investigated and optimal value of input parameters for reduced hole taper has been suggested. The experiments have been conducted by varying one parameter at a time. The experimental data are used to develop the multi regression model for hole taper. A reliable multi regression model is developed for hole taper and modern optimization tool, Genetic algorithm (GA) is used for optimization of the kerf taper. The optimal value of studied laser input parameters such as assist gas pressure, laser Current, stand-off distance, and cutting speed (Trepanning speed) have been suggested for getting lower value of hole taper. Finally, the effects of each laser input parameter of the kerf taper has been discussed.
关键词： Hole Taper,Laser Trapan Drilling,Inconel-718,Regression model,Genetic Algorithm
更新于2025-09-12 10:27:22
-
Investigation on geometric precision and surface quality of microholes machined by ultrafast laser
摘要： The geometric precision and surface quality of film cooling holes has significant influence on the cooling efficiency and fatigue life of turbine blades. In this paper, the investigation about fabrication process of film cooling holes on the single crystal superalloy DD6 plate specimen by ultrafast laser is carried out. By comparing three different processing paths, minimum roughness of hole wall could be obtained by concentric circular scanning, which was used in the followed-up experiment. The influence of process parameters on the geometric precision and surface quality of microholes was analyzed, and the physical mechanism was examined. The results show that among several process parameters, focus position has the most significant influence on the microholes geometric precision and surface quality, and that the divergent beam (where the focal plane is above the machined surface) can lead to smaller taper, roundness, and surface roughness. In addition, besides a layer of solidified debris adheres to the inner wall at the hole entrance, the microholes machined by ultrafast lasers have no other defects such as a recast layer, microcrack or heat affected zone.
关键词： Geometric precision,Surface quality,Process parameter,Ultrafast laser,Microhole drilling
更新于2025-09-12 10:27:22
-
Analysis of the laser drilling process for pilot holes in complex shaped components
摘要： In contrast to mechanical drilling, laser drilling can be applied directly to complex surfaces. The laser holes can thereby serve as pilot holes for mechanical deep hole drilling to produce high quality bore holes. This article examines the influence of pulse power, pulse duration and focus distance on the laser drilling process for curved surfaces using a Nd:YAG-Laser for the stainless steel X2CrNiMo17-12-2 and the case hardening steel 20MnCr5. By varying the laser parameters holes were produced that met the requirements for pilot holes in terms of diameter tolerances, drilling depth, conicity and material influences to enable the process combination.
关键词： process combination,laser processing,manufacturing technology,laser drilling,laser assisted processes
更新于2025-09-12 10:27:22
-
Helical drilling of three-dimensional conical converging-diverging nozzle in steel using ultrashort laser pulses
摘要： Three-dimensional conical converging-diverging nozzle typically a de Laval nozzle can be used for micropropulsion of microsatellites. The profile control, surface roughness and symmetry of the nozzle are key parameters to determine its performance. In this paper, we focus on the fabrication of a three-dimensional conical converging-diverging nozzle using helical drilling optics and ultrashort laser pulses. The helical optics makes it possible to dynamically control the profile of a hole by adapting the helical path during drilling process. An opening angle up to 18.6° on the converging part and 6.6° on the diverging part are achievable in 1 mm thick stainless steel by means of classic helical drilling. By introducing a dynamic helical process, the opening angle of converging part with straight profile can be extended to more than 90°. Moreover, the employment of an ultrashort pulsed laser has contributed to a high quality surface on the hole-wall having an average roughness less than 0.4 μm.
关键词： nozzle fabrication,ultrashort laser pulse,helical path,Helical drilling optics,shaped holes
更新于2025-09-12 10:27:22
-
Heat-Affected Zone Investigation During the Laser Beam Drilling of Hybrid Composite Using Statistical Approach
摘要： In the present work, basalt–glass hybrid composite has been fabricated and machined using laser beam drilling, to predict a safe machining zone pertaining to high drill quality with minimum heat-affected zone and maximum hole circularity. The prediction of the zone has been done by mathematical modeling using response surface methodology. The obtained zone has also been validated by performing more experiments. Moreover, the dependency of hole circularity and heat-affected zone on input parameters has also been discussed. From the results, it is evident that the obtained zone is capable of minimizing the heat-affected zone with acceptable hole circularity. Moreover, the behavior of input parameters is non-monotonic in nature.
关键词： Precise drilling,Heat-affected zone,Basalt–glass composite,Hybrid composite
更新于2025-09-12 10:27:22