Laser Equipment Research Articles

Power Monitoring System of Laser Welding Equipment

In order to improve the operation stability of laser welding equipment, reduce the failure rate of equipment operation. This paper designs a power monitoring system of laser welding equipment based on computer technology and communication technology. The system is mainly controlled by STM32 series processor. The upper computer of the power monitoring system is designed by C# language and .NET framework. Each module between the system realizes communication through socket and serial communication. Through real-time monitoring and analysis of key data such as welding power of laser equipment in the process of laser welding production process, the system realizes the functions of digital monitoring, data query, data storage, segmented data acquisition, equipment control, equipment running state analysis and so on. On this basis, combined with the network technology, the system realizes the functions of remote data monitoring and remote device log export, so as to improve the extensibility of the equipment and improve the operation economy of the equipment.

Elasticity Modulus and Hardness of Bearing Steel after Laser Treatment

The article considers the effect of laser treatment of bearing steel on the change in the elasticity modulus and hardness of the steel SHH15SG. Multi-factor models were obtained that relate the output parameters to the power W of laser radiation, the longitudinal feed Spr of the laser beam and the distance L from the protective glass of the focusing head to the workpiece surface. According to the degree of reduction of the influence on the elastic modulus of steel SHH15SG subjected to laser treatment, these factors are arranged in a sequence: W, Spr, and L. With increasing W and L the modulus of elasticity and hardness of the treated surface layer increase. 3M-XYZ surface-graphs, 3M-XYZ contour-graphs of interactive influence of independent factors on the elastic modulus and hardness of the surface layer are constructed, which simplifies the procedure for assigning the processing mode. The research results are useful for manufacturing and design companies that implement laser technologies and create laser equipment.

Implementation of laser equipment in a center experienced in lead extraction: safety and efficacy within 1-year follow-up.

Implementation of laser equipment in a center experienced in lead extraction: safety and efficacy within 1-year follow-up.

CO2 LASER HEAD NOZZLE FLOW ANALYSIS AND MODERNIZATION

With the passage of time and the development of technology, more applications are found in CNC controls with CO2 laser equipment. Laser machines with a CO2 source are increasingly distributed in woodworking and synthetic materials processing. Laser equipment makes it possible to produce high-quality and geometrically accurate products. The quality of the surface to be processed is directly related to the air flow intensity, which prevents sublimated particles burn to processed surface. The aim of the study is to increase air flow intensity by upgrading the internal design of the head nozzle. Simulations are created for modernized head nozzle that help to analyze the resulting data. Cutting and engraving is performed for wood material in working range for the head nozzle tests.

Low- level laser: cost of therapy fornipple trauma

Abstract Objectives: to measure the micro-cost of local laser therapy (LL) and transcutaneous laser therapy application by Irradiation Laser Intravascular of Blood (ILIB) to treat nipple trauma and compare the most effective and efficient alternative treatment. Methods: a cross-sectional analytical and quantitative study with analysis on the micro absorption cost, implemented as a clipping, from a randomized clinical trial that used two types of laser therapy to treat nipple trauma due to breastfeeding. The sample consisted of 101 nipple lesions. Patients were randomized into three groups (Control - CG, Local Laser -LLG and ILIB-ILIBG). Materials used, direct labor (DL) and laser equipment were predictors of costs. The delta calculation (effect size) was the indicator for measuring effectiveness and efficiency. Results: after three sessions, the average final cost was R$ 40.04for CG, R$ 53.55for LLG and R$ 67.29for ILIBG. After three sessions of treatment, ILIBG showed a great reduction in the lesion area, but with a higher cost (p<0.05). Conclusions: ILIBG had a better effect on healing the nipple trauma when compared to CG and LLG, even though it is more expensive, it suggests a positive cost-benefit and the most effective and efficient alternative treatment.

Modeling laser head housing and engineering by analyzing walls rigidity in CAE-systems

The paper considers a possible way to expand the technological capabilities of numerically controlled machines by upgrading and integrating a fiber laser system into their composition. An important task is to facilitate the details of laser head housing while maintaining their stiffness parameters. To achieve the aim of the research, the laser head body was completely redesigned, some structural elements were combined, and all the walls of the body became lighter and more functional. The new design will be much more convenient to use while maintaining the same rigidity. The new laser head housing will make it possible to expand the range of work for numerically controlled machines, which in turn will lead to a reduction in the production time of not only one product, but also the final product as a whole. This approach will reduce the cost of maintaining and maintaining a large number of equipment, since the integration of laser equipment into numerically controlled machines will reduce the number of equipment in the workshops. In addition, marking and manufacturing parts on the same machine will not only significantly automate the processes of further Assembly of the final product by applying QR codes, but also will increase the accuracy of marking and engraving on the product due to a one-step process.

Structural aspects and chemical analyses on cutting process of metallic-ceramic materials

Preliminary results on the behaviour of metallo-ceramic system during the cutting process were presented. The ceramic layer was obtained, after sandblasting of the substrate, through air plasma spraying with thicknesses of 30 μm on a steel substrate. Layers are chemically homogeneous, without cracks, pores or crevices. The thin layer (30 μm) present discontinuities with uncovered surfaces were the substrate is near in contact with the environment. Cutting process was realized on marking fiber laser equipment (Boron), of 30 watts’ maximum power and wave length of 1064 nm. There were obtained two different grooves on the test pieces with the following parameters: laser double pass at speed of 500 mm/sec, pulsed laser of 20KHz frequency and the beam power was set at 50% (around 15W) for the first groove) and at 80% (around 24W for the second groove). Structural, morphological and chemical evaluation of the cutting kerf was realized using scanning electron microscopy (SEM, Vega Tescan LMHII, SE detector, 30 kV, 15.5 mm WD) and energy dispersive spectroscopy (EDS, Bruker X-flash) using automatic/element list mode, Point, Mapping and Line features. This analysis highlighted the type of defects along the cut, respectively the phenomena occurring at the ceramic - metal interface.

Random forests for statistical modeling of experimental data for CuBr vapor lasers used as brightness amplifiers

This study demonstrates the high capabilities of data mining and the random forest (RF) machine learning technique for processing experimental data in the field of laser equipment and technology and extracting significant information from these. The subject of study is the copper bromide vapor laser, used as a brightness amplifier and as an active medium in active optical systems actively developed in recent years. Published data from 465 experiments on this type of laser are statistically examined. RF regression models are built to predict the output power as a basic laser characteristic. The dependence of the output power on the input electric power, the pulse repetition frequency, the pressure of the additional gases in the discharge, and other operating and geometric parameters of the laser is determined. The models fit up to 98% of the experimentally measured laser output power data.

Simulation of the solenoid scan method used in overlapping field for thermal emittance measurement

In one high repetition frequency X-ray free electron laser (XFEL) equipment, the electron gun and compensate solenoid have special structure in the photoinjector, thus the electric field and the magnetic field overlaps near the cathode. The thermal emittance of the cathode should be measured in the experiment. The solenoid scan method used to measure the thermal emittance is not suitable for the overlapping field, because it works effectively only when the rms emittance keeps constant. As the normalized phase space can avoid the influence of the electric field, we tried to use the solenoid scan method in normalized phase space. Using simulation code to do simulations and analysis, we finally demonstrate that this method is feasible for measurement of thermal emittance of the photoinjector which has overlapping field.

О МОДЕЛИРОВАНИИ ИЗМЕНЕНИЯ СМАЧИВАЕМОСТИ МЕТАЛЛИЧЕСКОЙ ПОВЕРХНОСТИ ПРИ ЛАЗЕРНОМ ТЕКСТУРИРОВАНИИ РЕЛЬЕФА

Over the recent years the researchers’ interest in the control of the wettability of metal surfaces with various liquids has increased due to a wide range of applications. In particular, the use of hydrophobic functional surfaces in thermal power plants and systems contributes to an increase in their efficiency and reliability. Despite the huge number of existing methods of hydrophobization of metal surfaces, the world scientific community has proposed and is intensively developing a method based on texturing micro-/nano-scale relief using laser equipment (laser ablation). The paper presents a study carried out to determine the effect of modification of brass surfaces using laser equipment on the geometric parameters of the textured relief and the properties of wettability, based on the results of which a mathematical model for predicting wettability was proposed.

Effects of photobiomodulation in pain and articular degeneration in mice arthritis model

ABSTRACT BACKGROUND AND OBJECTIVES: Rheumatoid arthritis is a set of symmetrical inflammatory processes that affects the joints. Currently, drug therapy is the first choice for the treatment of the disease, however it can cause serious side effects. In this context, photobiomodulation appears as a potential resource for treatment. Therefore, the aim of the study was to analyze the effects of low intensity laser treatment on pain and joint degeneration in the arthritis model in mice. METHODS: 24 mice were randomly divided into 4 groups with 6 animals each: SG, ZG, LG and DG. Zymosan was used to induce arthritis. The hyperalgesia was measured using the Von frey test. For the histological analysis, talocrural region samples were collected. Low intensity AsGa Laser equipment was used for the treatment, operating in 904 ηm wavelength, F:1000 Hz, W:50 mW and dose of 1 J/cm2. RESULTS: There was a significant difference (p<0.05) in all times of evaluation in hyperalgesia for the SG group compared with the ZG group, presenting an altered pain threshold. In the histological evaluation, the application of the laser (1 J/cm2) to the arthritic joint reduced the analyzed scores (1.20 ± 0.20) and showed a statistical difference when compared to the ZG group (LG=1.20 ± 0.20; ZG=3.80 ± 0.20, p<0.05). CONCLUSION The low intensity laser with the parameters described in the study was effective in reducing pain and promoting a protective effect on cartilage.

Laser welding of polyethylene films

Currently, the scope of application of laser welding is constantly expanding, in particular for the connection of polymer films of different types. This method of welding successfully competes with traditional methods, such as welding with heated tools and ultrasound in the light, medical, food and packaging industries. Advantages of laser welding are the absence of direct contact between the energy source and the heated surfaces and the ability to vary the intensity of heating by adjusting the temperature of the radiator and the distance to it. Currently, the most common laser welding technology is the transmission (permeable) method for overhead joints, which uses the effect of transparency of some polymeric materials for the laser beam. The transmission welding of low-power short-focus laser of polyethylene films of different types is carried out in the work. Knee welding was performed using a diode laser with a power of 1 W with a wavelength of 532 nm (green color of the visible light range). The laser on the clamping platform was moved along the connection line by means of a mechanical trolley. During welding, a 0.8–1 mm wide seam was formed and a slight convexity to the outside due to the expansion of the molten polymer material. Experimental studies of the influence of the main parameters of the laser welding process on the morphology of joints of polyethylene films of grades T and H. It is shown that welding laser films in the range of 0.015–0.1 mm does not require expensive laser equipment. A laser with a power of no more than 1 watt is enough to make a good connection. The quality of the welded joints of the films was evaluated by visual inspection, examination under a microscope and tear tests. Studies of experimental welds have shown their strength at the level of the base material.

Modeling of the PG-CP4 coating hardness applied to H12M steel and subjected to laser treatment

The article considers the influence of the radiation power W, the longitudinal feed Spr of the laser beam and the distance L from the protective glass of the laser focusing head to the workpiece on the PG-CP4 coating hardness which was applied to H12M steel by plasma and then subjected to laser treatment. A multi-factor model is established that relates the PG-CP4 coating hardness to the input process factors and allows you to quickly assign a laser treatment mode and to control it in order to improve the quality of the processed surface layer. Increasing W, Spr and L leads to a increase in the HV parameter. The longitudinal feed Spr of the laser beam has the greatest effect on the surface layer hardness, then followed the distance L and radiation power W. The research results are relevant for manufacturing enterprises that implement laser processing processes of materials and design organizations that develop modern laser equipment.

NiTi wires welding using a 500 W pulsed Nd:YAG laser equipment

The welding of NiTi shape memory alloys is an issue of highly importance for the generation of dissimilar and quasi-dissimilar architectures. Among the solutions for joining NiTi alloys, the laser welding has numerous advantages, among which: a low energy used in the process, the possibility to focalize the energy in a precise region and a large range of parameters used.The welding of the two NiTi wires with 0,74 mm diameter was performed using a commercially equipment (Nd3 +: YAG type PE-W500II Perfect Laser Co., LTD), leading to joints with an overlap factor of about 50% using the following parameters: 200 A current intensity, 5 ms laser beam pulse duration and 5.7 Hz pulse frequency.The welds obtained were analyzed by optical microscopy to characterize the NiTi memory alloy wires, the appearance of the weld and the compositional differences between the different areas of the joint.The fragile rupture occurred in the marginal area of the spot. It should be noted that the rupture occurred in the heat affected zone (HAZ), but not in the area of the welded joint, being typical for joints made without a protective atmosphere of Ar (inert gas).

Characterizing corrosion properties of carbon steel affected by high-power laser cleaning

A high-power CW laser equipment was used to irradiate bare carbon steel plates to evaluate the effects of laser surface cleaning on the corrosion properties of the base metal. Different laser processing parameters were adopted, representing lower to higher laser ablation effects. The surface oxide content was analyzed using XRD and SEM-EDX, the microstructure was observed under optical microscopy, and the corrosion properties of the specimens were evaluated using electrochemical tests. The results demonstrated that the CW laser-treated steel plates possessed better corrosion resistance than the unirradiated steel plates. Higher laser power density and interaction time result in denser iron oxide formed on the steel surface, which is the main reason for the improved corrosion resistance. Layers with modified microstructures are present in all laser-treated steel plates. The laser ablation effects and gradient microstructures can be well described by the theoretical peak temperature distribution. The laser surface cleaning technique for steel structures is thereby confirmed to have a positive impact on the corrosion properties of the base metal.

Experience in the use of MOSES technology for endoscopic treatment of benign prostatic hyperplasia

Introduction. The development of laser technologies in medicine and their introduction into everyday clinical practice determine the trend of using this type of energy in the treatment of patients with lower urinary tract symptoms caused by benign prostatic hyperplasia (BPH). In the last decade, holmium laser enucleation (HoLEP) of the prostate has been claiming to be «the gold standard» in the BPH treatment. The advantages of HoLEP over alternative technologies (transurethral resection, bipolar enucleation) in the BPH treatment have been demonstrated in randomized trials. These advantages include the reduction of the patient's hospital stay, safety of manipulation and high quality of life for the patient after surgery. The use of electrical energy in resection techniques for the BPH treatment in most cases is limited by the prostate volume (80 cm3). A better understanding of the effect of laser radiation and its clinical efficacy has led to increased interest and widespread adoption of laser systems. The constant search and improvement of existing approaches encourages urologists and surgical equipment companies to research new laser systems. One type of improvement is a software update for laser pulse modulation that has been developed to improve the efficiency of laser equipment. For the further development of new laser technologies and widespread use in routine clinical practice, it is necessary to compare them with standard methods of BPH surgical treatment with an assessment of the effectiveness, as well as the pros and cons of the compared methods.Purpose of the study. To evaluate the results of laser endoscopic treatment of patients with prostatic hyperplasia.Materials and methods. The study included 50 patients with prostatic hyperplasia who underwent two different types of surgery — HoLEP (group I; n = 25) and HoLEP with MOSES (HoLEP-M) technology (group II; n = 25). Inclusion criteria were: the presence of moderate or severe obstructive symptoms of the lower urinary tract, prostate volume &gt; 40 cm3, maximum urine flow (Q-max) &lt; 12 ml/sec. Exclusion criteria were: the presence of cystostomy drainage, an oncological process of the urinary system, an active inflammatory process of the genitourinary system, previous surgical interventions on the urinary system. I-PSS, QoL and IIEF questionnaires data, the level of prostate-specific antigen (PSA), the maximum flow of the urine stream (Q-max) and the post-void residual volume were assessed at baseline and 3 months after the operation. The main indicators of the compared methods, the number and nature of complications were studied.Results. Both methods of laser enucleation allow achieving a good functional result with a minimum number of complications. When comparing both methods in the group II of patients who underwent HoLEP-M, there was a statistically significant difference in terms of characteristics: the time of enucleation in group I (HoLEP) — 46.7 ± 15.0 min (31 - 80) vs group II (HoLEP-M) — 38.9 ± 7.6 min (30 - 60) (p = 0.03), but this did not affect the total time of surgery (p = 0.21), the level of haemoglobin postoperative changes in group I (HoLEP) — 7.5 ± 5.4 g/l (2 - 18) vs group II (HoLEP-M) — 5.0 ± 2.9 g/l (2 - 13) (p = 0.04) and irrigation time in the postoperative period, group I (HoLEP) — 17.6 ± 3.6 h (11 - 26) vs group II — 14.0 ± 4.3 h (5 - 21) (p &lt; 0.001). Thus, the results of the study suggest that the HoLEP with the modified pulse MOSES technology has advantages over the standard HoLEP technique. HoLEP-M allows you to perform the enucleation stage faster, with better hemostasis and minimizes the effect of the laser on the surrounding tissues. Complications above level 2 were not observed in both groups according to the Clavien-Dindo scale.Conclusion. HOLEP-M is a safe method of surgical treatment of prostatic hyperplasia from the point of view of surgical safety, efficacy, as well as the duration of the patient's recovery period and can serve as an alternative to the HoLEP standard technique.

Improve Chip Side Wall Crack Issue in Nanometer Packing Process of Semiconductor

The chip side wall crack of semiconductor nanometer packaging process has always been an important technological problem that the global semiconductor packaging industry needs to overcome. This research has helped the world's biggest semiconductor package factory to improve the chip side wall crack issue faced by nanometer wafer packaging process, thus enhancing its yield rate. After analyzing the abnormality of nanometer wafer packaging process, this research team found that the chip side wall crack problem was caused by a poor laser waveform during the laser cutting process, resulting in debris along the chip side wall. Subsequently, as the diamond cutter cuts into the chip in the following process, the cutter impacts the debris which then impacts the side wall resulting in a side wall crack. The Teoriya Resheniya Izobreatatelskikh Zadatch (TRIZ) analysis was used to deduce a suitable improvement method. After applying the TRIZ analysis, this research team confirmed that by modifying the laser equipment to create a more uniform laser waveform, the diamond cutter was able to achieve a clean cut of the chip without impacting debris and thus significantly decreased the chip side wall crack occurrences. The shipment yield rate was increased from 92.8% to 99.61% as a result of the team's modifications.

Influence of Different Strain Hardening Models on the Behavior of Materials in the Elastic-Plastic Regime under Cyclic Loading.

In exact analyses of bodies in the elastic–plastic regime, the behavior of the material above critical stress values plays a key role. In addition, under cyclic stress, important phenomena to be taken into account are the various types of hardening and the design of the material or structure. In this process, it is important to define several groups of characteristics. These include, for instance, the initial area of plasticity or load which defines the interface between elastic and plastic deformation area. The characteristics also include the relevant law of plastic deformation which specifies the velocity direction of plastic deformation during plastic deformation. In the hardening condition, it is also important to determine the position, size and shape of the subsequent loading area. The elasto-plastic theory was used for the analysis of special compliant mechanisms that are applied for positioning of extremely precise members of the Compact Linear Collider (CLIC), e.g., cryomagnets, laser equipment, etc. Different types of deformation hardening were used to simulate the behavior of particular structural elements in the elastic–plastic regime. Obtained values of stresses and deformations may be used in further practical applications or as default values in other strain hardening model simulations.

Investigation on the peak temperature and surface defects on the carbon steel treated by rotating CW laser

A newly developed rotating continuous-wave laser equipment was adopted as an alternative laser-based surface cleaning method. To evaluate the thermal effects of laser cleaning on base material, a modified calculation method for laser-induced peak temperature distribution considering overlapping effects was proposed. Various laser-processing parameters were adopted to irradiate carbon steel plates. The re-melted zone (MZ) of laser-treated specimens was observed under optical microscopy and used to verify the calculation method. Surface morphologies and roughness of laser-treated specimens were also investigated. The results showed that the peak temperature distribution obtained from the modified calculation method properly describes the MZ depth in laser-treated specimens. Investigation on laser-treated specimens revealed that results of laser heat effects improved in rougher surface conditions, and that frequent overlapping of laser beam can induce surface defects. The modified calculation method could help to optimize laser processing parameters to reduce melting of base material and avoid surface defects.

Surface finishing by laser re-melting applied to robotized laser metal deposition

Low surface quality of as-deposited laser metal deposition (LMD) parts is one of the main drawbacks of this additive manufacturing technology that prevents direct use without the implementation of costly and time consuming post-processes. An in-process surface finishing operation without the need of auxiliary equipment is highly appealing to overcome such issues. For this reason, laser re-melting performed with the same laser equipment used for the deposition process is a promising technology capable of redistributing the deposited material onto a smoother surface. Combined with a robotic manipulation system used for both the LMD and laser re-melting phases, complex geometries can potentially be produced in near net-shape conditions. An important issue concerning development of this process development regards the use of standardized roughness and waviness parameters, which can fail to address the texture specific to the LMD process. Indeed, the laser re-melting process can produce new texture formation under non-optimal conditions. Hence, an analysis of the surface topography in the frequency domain along with the standard surface roughness and waviness parameters would be more appropriate. In this work, laser re-melting is applied to AISI 316L thin walled structures right after the deposition process. An experimental campaign aimed at finding the process parameters and re-melting strategy capable of improving the surface quality was carried out. Areal surface profile measurements were used for characterizing the effect of the process parameters. The surface power spectrum on the S-F surface was calculated to point out the presence of periodical components in the surface structure and a transfer function calculation was performed to define the surface quality improvement in the frequency domain compared to the LMD as-deposited surface. The acquired surface areal data was assessed at two different spatial frequency regions corresponding to the S-L and L-F surfaces. The arithmetic average of the filtered surface areal data was used to calculate Sa, SF and Sa, LF analogously to the average roughness and waviness parameters of linear measurements respectively. Results showed, in the optimized conditions, a reduction of up to 79% in Sa, SF corresponding to the roughness related frequency range. On the other hand, the Sa, LF parameter corresponding to the waviness realted frequency range was reduced up to 58% due to the low effectiveness of laser re-melting in reducing the amplitude of the lowest frequency components. The overall improvement in terms of process capability was evaluated as mean ± 3 times the sample standard deviation values (µ±3σ). The average surface roughness Sa, SF could be reduced from 10.35±0.42 µm to 1.92±0.11 µm and average surface waviness Sa, LF from 9.57±0.48 µm to 4.04±0.20 µm.