Although lasers have, for some time now, been used for performing a wide range of industrial material processing tasks, most of these applications have involved simply moving a workpiece under a fixed laser beam - in order to accomplish the specific processing action desired. This method of doing laser material processing, although highly effective, produces certain limitations on the overall shape of the workpiece that can be processed. As such, a number of manufacturers of laser material processing systems now supply units which instead fix the workpiece - and provide the necessary processing motion by moving the laser beam itself. In the following, systems having different degrees of laser beam manipulation capability are fully described - and the enhanced flexibility this method of laser processing provides users is then discussed in detail.
Laser machines may look like their counterpart conventional machines, but are uniquely designed to integrate high-technology YAG and CO2 laser technology. This paper will discuss motion, CNC controls, accuracies, reliability and design of laser motion systems. State-of-the-art contributing to high performance advanced manufacturing.
This paper introduces some of the important aspects of using lasers with robots for an automated environment. Salient features of a laser robotic cell are discussed. Potential error sources are illustrated. The goal of this paper is to provide a background for understanding the makeup of today's laser robotics systems.
As the definition of flexible manufacturing systems is refined the laser will play an increasingly important role. In sheet metal FMS the versatility of lasers has already made an important impact. New laser designs will help FMS to evolve frau marginal functionality to a mature manufacturing reality. This paper addresses the role that lasers play in FMS and the parameters successful implementation imposes upon them.
The main processing objects assembled in this machine are precision workpieces. The entire electro- optical mechanical system possesses high accuracy, high stability, and produces a continuously variable waveform of the laser pulse. These qualities enable extremely difficult processing, such as processing very small pieces of different material. Several new techniques were developed, and some main techniques are described: Waveforms are electronically combined to adjust the laser pulse waveform and pulsewidth. A new positioning system using a micro-light spot to indicate position is designed. The precision of laser voltage is very high. It is measured to 0.01% and the laser intensity stability is 1%. The current-limiting resistance is eliminated in the Xe lamp pre-lighting circuit. This results in high pre-lighting stability and less heat. Some other relatively perfect measures are also taken. Practical use of this machine has proven high processing capability.
Industrial lasers are doing more than capturing the spot light in materials processing - they are and have been contributing significantly to bottom line of progressive manufacturers who see themselves competing in domestic as well as global markets. Markets where product innovation and manufacturing productivity are key ingredients to success.
The capability of focusing large amounts of energy onto a very small area makes the laser a useful tool for cutting and drilling materials. With the aid of appropriate aperture, lens, and careful selection of laser parameters, we have been successful in cutting slots 0.001 inches (0.025 millimeters) in width and drilling holes 0.00015 inches (0.0038 millimeters) in diameter. Examples of these applications are shown. Cutting and drilling of foil thicknesses (less than 0.010 inches thick) poses a special problem. Despite careful selection of operating parameters there is normally some small amount of dross adhering to the bottom surface of the foil. We have found that various surface coatings can be used to protect the foil from damage both during processing and cleanup. Several examples illustrate the surface quality of cuts achieved with coated foils.
A number of surface-monitoring optical techniques are presented for the on-line quality control of materials produced at high production rates. A laser-scattering approach is described for surface-quality inspection of the hot-dip zinc coating in a steel galvanizing line. The detection of localized specular reflectivity, coupled to the fast sheet motion, proved to be an effective method to monitor coating properties such as spangle grain size. Similar investigations are described for the on-line inspection of polymer-coated electric cable. Our approach for such an inspection problem is based on the projection of a uniform-intensity laminar beam across the cable and on the bandpass-filtered detection of the transmitted beam to obtain a resolution better than 5 μm independently of the extruded-cable vibrations. Results of in-plant trials are reported.
Advantages and construction principles of laser soldering systems are discussed. First results with a production type Y AG laser system soldering SMD components are presented: Small and fine grain intermetallic zones, high mechanical strength, component size up to 40 x 40 mm2, soldering speed 28 pads per second.
It is difficult to get a good welding spot and nearly impossible to weld a 10 micron diameter filament (e.g. NiCr) onto a foreign workpiece over 1000 times larger in size. In this paper we introduce the laser powder-covered welding technique. The first step is to laser- weld a metal powder onto a small area of interest of a larger-sized workpiece. This changes the nature of the larger-sized material. The second step is to position the thin filament in contact with the larger workpiece and to apply the pulsed laser so a round and smooth welding spot forms. This should form a good alloy combination. This welding technique has a high success rate for welding minute electrical heat source, independent of the material of the larger workpiece. This technique also solves the problems of unstable quality in tin welding, burrs in pressure welding, and eliminates the problem of welding flux corrosion. This same technique is applied to the laser-welding of a super-thin piece to a foreign workpiece, where the welding spot forms a "micro-rivet': In the paper we present specific conditions required, the analysis data of the welding quality and the specific structure of the laser-welding workstation.
A brief review of a laser as a machine tool is given together with drilling mechanism. The effects of the variation of laser machining parameters and materials on the hole geometry are examined for Nimonics 75 work-piece material. A statistical approach known as a factorial design is employed to identify the levels of significance of factors that are most important to hole quality. The variation of focal settings with workpiece thickness are also examined. The results obtained showed that the optimal focal setting becomes smaller than the nominal focal position of the focussing lens for the samples thicker than 0.5 mm, but this is reversed for the samples thinner than 0.5 mm.
We will start by looking at some of the characteristics of the aerospace industry in Table 1 below. Job shopping for the aerospace industry Characterized by: Cyclical swings Other discontinuities Complex network of subcontractors Interesting, diverse and difficult applications Leading edge materials Stringent quality requirements and approvals Tight deadlines
Laser wire stripping is now an established process. This report describes the application presently in use and its advantages. A new process is also disclosed that strips polyimide coated "magnet" wire. The new laser process eliminates the previous problem of removing the polyimide coating completely which now allows soldering of the laser stripped wire immediately after laser stripping without the need for any cleaning steps in between.
With the expanding application of laser machining in the industrial environment, various laser types such as CO2, Nd:YAG and Nd:Glass have to a certain extent been identified for use in specific applications, both by laser manufacturers and the user community. The CO2 laser, and in particular the newer fast axial flow laser, is becoming linked with sheet metal cutti g systems and what might be ter ed "industrial" iaterials processing. These lasers are in many cases being looked at to replace or complement more conventional manufacturing techniques; such as, punch and die, shearing, blanking and milling for low volume part quantities. Quality and part tolerance obtained from the CO2 laser in these cases often meet or exceed that which is obtainable by the conventional technique. If one begins to consider the manufacture of precision parts such as the type obtainable through techniques; such as, photofabrication or fine blanking, the answer that is generally accepted by the laser community is that the parts must be manufactured by the solid state lasers, Nd:YAG or Nd:Glass. No argument can be made concerning the part quality obtainable with the solid state lasers; however, precision cutting approaching and often equaling the solid state lasers is obtainable with the CO2 laser. Precision CO2 laser cutting might by some standards be considered more of an art than a scientific application; however, by utilizing standard equipment and simple processing techniques, high quality precision CO2 laser cut parts are obtainable both in the laboratory and on the production floor for the industrial user.
This paper describes the planning which was involved to successfully install the first high power laser system at this particular operating division. The production system laser welds automatic washing machine transmission gears. Included is a description of planning through product redesign, process design and development, installation, manufacturing and maintenance. Whirlpool's Total Quality Assurance program was instrumental in ensuring proper planning and communication took place well in advance of the equipment arriving at the plant.
There is no comnon denominator for non-traditional holemaking. Each process has its own unique capability. This document is concerned with the high-power Nd:YAG solid-state laser product as it is used in the material process industry. Economical comparisons and abilities to drill at shallow entry angles to a surface are discussed, and the range of hole sizes found to be practical for production laser applications are reviewed.
We begin with conventional laser processing equipment. The first is a conventional marking system with a small work station and a very simple beam delivery. Although it is not three dimensional, we may move a part around in order to access some of its areas.
A simplistic model is developed to include the major elements which most manufacturing operations consider before incorporating laser processing technology. This is essentially the same model which is used when implementing any other manufacturing technology. First, laser system costs are summarized using a few generalized rules. Then, processing costs (cutting, welding and heat treatment) are summarized using illustrative estimates. These two areas are balanced against the potential gains by manufacturing strategic planning.
The high power output capability of a CO2 laser has been shown to be an excellent source of controllable heat, allowing for the application of hardface alloys on substrates with very low dilution and consistent thickness. Enormous opportunities exist in the aircraft, automotive, and oil and gas exploration industries for such an alternate to conventional hardfacing equipment and techniques. Yet, the majority of experimentation with lasers thus far thas been on flat surfaces only. This report reflects preliminary findings on the geometric capabilities of the laser cladding process.
Nd:YAG lasers with periodical Q-switch have now established themselves in industrial marking. They are mainly used for marking metals, plastics, ceramic and foils. Some marking examples follow. The engraving depth, as well as material interactions dependent on laser parameters are explained with the help of micro samples on metals.
Laser Marking has become a widely accepted technique to label a large variety of materials from hard carbide ceramics over packaged microelectronic devices and a variety of metals to coated cardboard boxes, traditionally using lasers with high power and good overall efficiency, such as CO2 and Nd:YAG lasers. Most of the materials being marked, in particular organic substances like plastics and varnishes undergo a more or less pronounced burning or ablation of the surface which leads to a relief structure. We have developed a method to mark plastic materials which contain some particulate filler (pigment, dye or additive) using laser pulses of shorter wavelength than most of the known processes, which therefore are not absorbed by the matrix material.
The application of laser markers for marking machine readable codes is described. Use of such codes for automatic tracking and considerations for marker performance and features are discussed. Available laser marker types are reviewed. Compatibility of laser/material combinations and material/code/reader systems are reviewed.
Technical and economical aspects of laser marking systems are discussed and compared with traditional marking techniques. Laser marking has two main principles: mask or stroke marking. Examples of important TEA CO2 and Y AG laser marks and their applications are described. Laser marking is superior in quality and flexibility; it lends itself to automation and integrated production technologies. It is the most cost efficient method of permanent marking, especially in high throughput production lines.