Jacek Reiner

Parameters in selective laser melting for processing metallic powders

The paper presents results of studies on Selective Laser Melting. SLM is an additive manufacturing technology which may be used to process almost all metallic materials in the form of powder. Types of energy emission sources, mainly fiber lasers and/or Nd:YAG laser with similar characteristics and the wavelength of 1,06 - 1,08 microns, are provided primarily for processing metallic powder materials with high absorption of laser radiation. The paper presents results of selected variable parameters (laser power, scanning time, scanning strategy) and fixed parameters such as the protective atmosphere (argon, nitrogen, helium), temperature, type and shape of the powder material. The thematic scope is very broad, so the work was focused on optimizing the process of selective laser micrometallurgy for producing fully dense parts. The density is closely linked with other two conditions: discontinuity of the microstructure (microcracks) and stability (repeatability) of the process. Materials used for the research were stainless steel 316L (AISI), tool steel H13 (AISI), and titanium alloy Ti6Al7Nb (ISO 5832-11). Studies were performed with a scanning electron microscope, a light microscopes, a confocal microscope and a μCT scanner.

System for laser microsurfacing of metal powders

The article presents the technology of laser cladding of metallic powders and a machine for laser microsurfacing developed for this purpose. This specifically designed and manufactured station is based on a three-axis CNC machine, equipped with appropriate laser safety systems and a dust extraction system. A disc laser is used as a source of laser energy, connected with the processing optics by a fibre optic cable. A brush powder feeder with a nozzle for shaping the flow of powder transfers the powder coaxially with the laser beam. The system is integrated with a PC-motion card which acts as a CNC controller. The article also presents the results of laser surfacing experiments, classified in terms of the following criteria: surfacing height, width and depth of penetration, wetting angle and microstructural parameters. The laser power density, powder feeding rate and density, as well as the relative movement of the welding head against the component, have been selected as independent parameters.

Rendering for machine vision prototyping

Machine Vision systems for manufacturing quality inspection are interdisciplinary solutions including lighting, optics, cameras, image processing, segmentation, feature analysis, classification as well as integration with manufacturing process. The design and optimization of the above systems, especially image acquisition setup is mainly driven by experiment. This requires deep know-how and well equipped laboratory, which does not guarantee the optimal development process and results. This paper proposes novel usage of rendering, originating from 3D computer graphics, for machine vision prototyping and optimization. The invented technique and physically-based rendering aids selection or optimization of luminaires, tolerancing of mechanical construction and object handling, robustness predetermination or surface flaw simulation. The rendering setup utilizes mesh modeling, bump and normal mapping and light distribution sharpening with IES data files. The performed light simulation experiments for metal surfaces (face surface of bearing rollers) are validated.

Knowledge Management Issues For Maintenance of Automated Production Systems

Today’s maintenance approach is functional oriented and mostly it is understood as hardware preventative actions. The changing share of mechanics, electronics and software cost of automated production systems call for new competences and responsibility for efficient maintenance. The paper presents automated production system which is considered as socio-technical system whose effective maintenance is based on knowledge management. In this paper Object-Oriented Modelling and UML were pointed to, as enhancing communication and documentation effectiveness in interdisciplinary teams responsible for maintenance.

Examples of Laser Processing Control with Machine Vision Feedback

Manufacturing technologies using laser radiation energy are gaining increasingly new applications. It results from their numerous advantages, most of all, from the selectiveness of a laser beam within the spatial and temporal domain. Although the laser beam is a very precise tool, it restricts the tolerances of component preparation. If such increased requirements drive previous processes, it will result in the increase of manufacturing costs of these parts. Hence, solutions are sought in the mechatronics paradigm, which corrects mechanical imperfections by means of electronics and software. Examples of the above solutions are follow-up and adaptive control systems. The paper presents examples of developed and implemented control systems of laser manufacturing processes with machine vision feedback. They include remote cutting with CAM-MV and laser cladding with a thermal or geometric closed-loop.

PROJEKTOWANIE I ANALIZA ZASTOSOWAŃ TECHNOLOGII NAPAWANIA LASEROWEGO DLA BRANŻY LOTNICZEJ

Technologia napawania laserowego polega na wykorzys taniu wiązki laserowej celem precyzyjnego nało żenia warstwy materiału o podwy ższonych właściwościach na podłoże. Szczególne zainteresowanie budzi ona w bran ży lotniczej. Odpowiednie przygotowanie procesu wi ąże się z wykonaniem testów symulacyjnych z wykorzystaniem modeli przepływu dwufazowego oraz interakcj i wiązki laserowej z materiałem. Nast ępnie zostaj ą wyznaczone ścieżki ruchu głowicy przy użyciu dedykowanych narzędzi CAD/CAM. W ramach analizy technologii napawania laserowego dla zastosowa ń branży lotniczej przedstawiono nakładanie powłok funkcjo nalnych, będących alternatywą dla chromu elektrolitycznego. Przeanalizowano równ ież metodę regeneracji wierzchołka łopatki turbiny silnika odr zutowego. Zaprezentowano te ż możliwości obróbki hybrydowej w wytwarzaniu przyrostowym ty tanowych komponentów lotniczych oraz metod ę monitorowania temperatury celem jako ściowej kontroli procesu.

Real Time Trajectory Correction System Of Optical Head In Laser Welding

Abstract Application of laser welding technology requires that the laser beam is guided through the whole length of the joint with sufficiently high accuracy. This paper describes result of research on development of optomechatronic system that allows for the precise positioning of the laser head’s TCP point on the edge of welded elements during laser processing. The developed system allows for compensation of workpiece’s fixture inaccuracies, precast distortions and workpiece deformations occurring during the process.

HIGH TEMPERATURE PROPERTIES OF MINIATURIZED THICK-FILM COMPONENTS

This paper presents systematic studies of thick-film or LTCC microcomponents (capacitors, inductors) made with the aid of laser-shaping and operating at temperature up to 450 °C. The minimum dimensions i.e. conductive path width and spacings were about 30 μm. Such small patterns have been created by laser cutting of fired Au- or Ag-based conductive films. Laser system equipped with Nd:YAG-laser (beam wavelength of 1064 nm) was applied. The inductance, capacitance, as well as parasitic impedances were measured in the frequency range from 10 kHz to 110 MHz and temperature between 25 °C and 450 °C.

Object Oriented Paradigm for Manufacturing Automation

Abstract The object oriented approach is usually identified as C++ or Java programming languages. Therefore, its usefulness for automation, based on classical hardware, e.g. PLC and fieldbus, is doubtful. At the same time, software and integration intensive automation systems suffer from limitations of presently used methodologies, originating in relays logic circuits. The authors discuss the current state-of-the-art in the field of object oriented automation for flexible manufacturing systems. Modelling and simulation, as virtual mechatronics for distributed control systems, is introduced.