Horizontal Xy Research Articles

ДОСЛІДЖЕННЯ МЕХАНІЧНИХ ВЛАСТИВОСТЕЙ ТА СТРУКТУРИ СПЛАВУ IN718, ОТРИМАНОГО МЕТОДОМ 3D-ПРИНТИНГУ

The subject of research – the process of structure formation and improvement of mechanical properties of high-resistant alloys obtained by 3D-printing. The purpose of work – control the level of mechanical properties of high-resistant alloys obtained by 3D-printing for the manufacture of parts of aircraft gas turbine engines. Objectives – experimental determination of mechanical properties of heat-resistant nickel alloy IN718 obtained by selective laser sintering of LPW and Sino Euro powders both in the horizontal XY and in the vertical Z direction; a comparative analysis of the mechanical properties of IN718 and ЭП718-ВД(ИД) (ХН45МВТЮБР) alloys according to ASM 5662M and TU 14-1-3905-85; a study of the structure of samples of IN718 alloy before and after heat treatment. Research methods – when summarizing and analyzing scientific and technical literature in the direction of studying mechanical properties and forming the structure of heat-resistant nickel alloys obtained by the method of selective laser sintering, an integrated approach was used; processing and analysis of experimental data on determining the mechanical properties of the IN718 alloy in the three-dimensional direction (horizontal direction XY and vertical direction Z); metallographic studies of samples of the IN718 alloy made by 3D-printing were carried out before and after heat treatment. The results obtained - by comparing the mechanical properties of the heat-resistant alloy IN718 obtained by 3D printing from powders LPW and Sino Euro with the normative characteristics ASM 5662M (for alloy IN718) and TU 14-1-3905-85 (for alloy ЭП718-ВД) it was found that for vertical samples (grown in the Z direction) a certain decrease in the strength characteristics and an increase in plastic characteristics compared with the values of horizontal samples (grown in the XY direction), and in terms of impact strength, the IN718 alloy exceeds the norm in the researched temperature range 3.75 times. Scientific novelty – the dependence of the structural characteristics and mechanical properties of the IN718 alloy on the direction of part growth has been established and it has been shown that after heat treatment it is possible to obtain a dense, uniform microstructure characterized by a fine-grained structure with micro grains that are elongated in the direction of sample growth.

Nanoindentation of cement stone samples

The preliminary results of the studied cement samples were obtained by the nanoindentation method. It was revealed that the elastic modulus M increases in samples that contain a complex additive containing nanosized particles. The effect is also observed with the introduction of an additive containing only one type of nanoparticles (nanosilica sol SiO2 or carbon nanomaterial MCNT). The selection of the parameters of the nanoindentation method, which ensured the obtaining of the final consistent results, was performed. These results are presented by histograms of the distribution of nanoindentation points in modulus of elasticity M and hardness H and distributions in M and H in the horizontal XY plane perpendicular to the motion of the nanoindentor. The results obtained indicate that there is a change in the nanostructure of the C – S – H gel, which is compared with an increase in strength, Young’s moduli and shear, upon the introduction of SiO2 nanoparticles and MCNT nanoparticles.

Возможности прецизионной микрообработки материалов импульсным излучением лазера на парах меди

The paper reports the results of experimental researches on microprocessing by laser copper-vapor radiation with wave-lengths of radiation in the visible spectrum region of 510.6 and 578.2 nm and the frequency of pulse repetition of 14-15kHz, a nano-second duration of pulses and a peak power density of 109-1011 W/cm2 in the focused spot light with the diameter of 10…20µkm. The investigations carried out became a basis for the creation of modern automated laser technological plants “Caravelle-2” and “Caravelle-2M” and with the average radiation power of 6-8W, an operation field of horizontal XY- table 100x100 and 200x200mm and positioning accuracy on axes ±2µkm for the precision micro-machining of foil materials – 0.01-0.2mm; “Caravelle-1” and “Caravelle-1M” with the radiation power of 10-15 20-25 W, an operation field of XY-table 150x150mm for the thin-sheet material micro-processing – 0.3-0.5mm and 0.6-1mm. The productivity of the plants mentioned as compared with common methods including also EEM is by an order and more higher. Material micro-processing with laser nano-second copper-vapor radiation ensures a higher quality of a cut: minor roughness of a cut surface (≥1…3µkm) and the area of thermal impact (≤3…5µkm) and stratifications and micro-cracks do not appear in such heat-resistant material as molybdenum and tungsten.

Performance analysis for a novel adaptive algorithm for real-time point cloud ground segmentation

This paper proposes a fast algorithm for ground segmentation of point clouds. It differentiates ground points from obstacle points from unstructured point clouds. This segmentation consists of performing an orthogonal projection into the horizontal xy plane followed by a top-down area subdivision. This process self-adapts to the point cloud, focusing processing effort on detailed areas. Real-time performance for execution in low cost embedded devices is demonstrated through quantitative and qualitative test results.

Micro EDM Milling with Electrochemical Fabrication of Ultra-thin Microtools and Mapping of Electrical Microdischarges

The aim of this paper is to describe some possibilities allowed by a micro EDM milling machine, which has been entirely developed in our laboratory. Among other features, this machine does not make use of WEDG for fabricating the microtools. Instead of this, a compact low cost electrochemical reactor allows automated etching of tungsten microtools with a diameter ranging from 1 to 30μm and very high aspect ratio (50-100). Thus, fragile microtools are obtained and regenerated without any intervention by the operator. Micro EDM milling is performed with such microtools thanks to a specially designed electronics based on a parallel architecture with 3 microcontrollers. The electrical signals of the micro discharges are continuously characterized which allow mapping of micro electrical discharges and contacts. It is demonstrated that the spatial distributions of discharges and contacts give valuable information on the micro EDM milling process. During the machining of microchannels in stainless steel, it is reported that the positions of contacts match with a low number of discharges. So, high tool wear and low part removal rate are related to a high number of contacts. Heterogeneous machining along the vertical Z axis and the horizontal XY axis can be also characterized.

Vektorizacija poteka daljnovodnih vodnikov s houghovo transformacijo iz podatkov aero- in terestričnega laserskega skeniranja

n this article, a method for the automatic detection of power lines in a horizontal xy plane from airborne and terrestrial laser scanning data is presented. The workflow is composed of four main steps: pre-processing with classification of a point cloud, filtering of the point cloud, the detection of points on the power lines by applying the Hough transform (HT), and vectorisation of power line locations and their intersections. In the pre-processing step, most of the points that are not representing power lines are eliminated via classification of the point cloud. We present our filter, which reduces the number of points in the point cloud further and thus accelerates data processing and increases the reliability of processing in the next steps. We detect the points on the power lines with the HT on the vector points in the xy plane. The final track of the power lines is derived from the straight segments computed by the method of the least squares from the points that HT recognised on the power lines. The results are assessed visually and via relative comparison of the computed intersections coordinates with the reference data manually extracted from the filtered point cloud. The proposed method detects almost all power lines in the test area for both data sets

A scanning contact probe for a micro-coordinate measuring machine (CMM)

A new high precision contact scanning probe able to measure miniature components on a micro/nano-coordinate measuring machine (CMM) is proposed. This contact probe is composed of a fiber stylus with a ball tip, a floating plate and focus sensors. The stylus is attached to a floating plate, which is connected to the probe housing via four elastic wires. When the probe tip is touched and then deflected by the workpiece, the wires experience elastic deformations and the four mirrors mounted on the plate will be displaced. These displacements can be detected by four corresponding laser focus probes. To calibrate this touch trigger probe, a double-trigger method is developed for a high-speed approach and a low-speed touch. Experimental results show that the probe has a symmetric contact property in the horizontal XY plane. The contact force is found to be about 109 µN. The standard deviation of the unidirectional touch is less than 10 nm and the pre-travel distance is around 10 nm with a standard deviation of less than 3 nm.

Distribution of static pressures on the skin surface of parallely swimming fish

Hydrodynamic static pressures on the body surface of fish generated by conspecifics parallely swimming were measured in a flume tank, and they were compared with those generated by changing the position of two individuals under different flow velocities. Two dead common carp (BL=20 cm), fixed in 20% of formalin, were used. Pressure was measured by a manometer connected to the ends of three aluminum pipes (inner diameter=3 mm), which were inserted perpendicularly to the body axis from right to left in the control fish. The openings of the pipes were located on head, trunk, and caudal regions, and each was on the infraorbital or trunk canal lateral lines. The target fish was moved on the horizontal XY plane using a traverse device. Although pressures changed depending on the regions measured, changes of pressure according to position and current velocity were relatively low in the caudal region. The absolute values of the pressure increased as flow velocity increased, and decreased with an increase in the distance between individuals. Relative positions when the maximum pressure changes were observed at each flow velocity did not change, indicating that pressures were largest when the maximum body width of the conspecific is closest.

Steering and Depth Control of an Underwater Robot Using Fuzzy-Like PD Controller

The design of a steering and depth control of an underwater vehicle is of interest from the point of view of motion stabilisation as well as manoeuvring performance. The paper describes how a Fuzzy-like Proportional Derivative Controller (Fuzzy-like PD Control) is used to control the course-changing and course-keeping tracking mission and motion of an underwater vehicle. The idea for this type of control architecture is to identify the optimum values, in terms of control performance and robustness, of the parameters of the F-like PD Controller. These parameters may be the scaling factors that are applied in the input/output of the PD part of the controller as well as the fuzzy sets of the fuzzy part of the controller. The values of the scaling factors for the error, the change-of-error and the control output are optimised based on experiments. In this work a method has been developed to control the yaw and depth of an underwater robot in terms of course-changing and course-keeping. The controller is synthesised in two parts. Firstly it is applied in horizontal xy and secondly in vertical xz surface. Experiments in a real environment were planned using the Taguchi Design of Experiments and performed to investigate the capabilities of the controller. The results are presented and analysed extensively.