Laser Cutting Applications 265
This class describes laser cutting methods and processes and common setup tasks for laser cutters. Laser cutting offers many benefits over mechanical cutting, including faster production times and greater precision. In addition, laser cutters are practical for a range of processes, including cutting end-use parts, rapid prototyping, etching, and engraving.
After completing this course, users will be able to identify common laser cutting processes and will have a basic understanding of laser selection, setup, and safety. This information will allow them to work with laser cutters efficiently and safely.
Number of Lessons 13
- Benefits of Laser Cutting
- Laser Cutter Selection
- Equipment and Software Setup
- Focal Length and Spot Adjustment
- Cutting Parameters
- Review: Laser Cutter Setup
- Laser Cutting Methods
- Laser Processes: Material Removal
- Laser Processes: Marking and Welding
- Review: Laser Methods and Processes
- Laser Cutter Maintenance
- Laser Cutting Safety
- Final Review
- Describe laser cutting and its benefits.
- Describe considerations for selecting a laser cutter.
- Describe setup for laser cutting equipment and software.
- Describe the focal spot and how to adjust it.
- Describe common cutting parameters for laser cutters.
- Describe the five main laser cutting methods.
- Describe common laser material removal processes.
- Describe laser marking and welding.
- Describe common tasks for maintaining a laser cutter.
- Describe laser cutting safety.
A device that catches particles of dust, soot, vapor, and debris and prevents them from passing through it. Air filters in laser cutting systems should be regularly cleaned and changed.
A laser marking process that permanently changes the color of a part by oxidizing its surface. Annealing can produce black and other colors on ferrous metals.
A colorless, odorless, non-reactive gas. Argon is sometimes used as an assist gas in laser cutting.
A gas used during the laser cutting process to remove molten metal from a cut. Assist gases include compressed air, nitrogen, argon, helium, and oxygen.
assist gas delivery system
The collection of canisters, gauges, hoses, and/or other accessories that move assist gases from their storage place to the laser during laser cutting. Assist gas delivery systems should be regularly inspected for leaks and debris and to ensure proper temperature and fluid levels.
A specific number of identical parts that move through the production cycle as a group. Batch parts can be produced by laser cutters very quickly and precisely.
An optical device with a semi-transparent mirror that divides a beam of light in two. Beam splitters allow some light to pass directly through while sending the rest of the light in another direction.
A sharp, ragged projection on the edge or corner of a workpiece that is left behind after a cutting operation. Burrs are functionally eliminated by laser cutting processes.
A laser marking process that permanently changes the color of a part by burning its surface. Carbonizing always produces a darker color and only works on materials that contain carbon, such as organic materials and some plastics.
A hard, brittle material that can withstand high temperatures and resist corrosion. Ceramics include traditional materials such as brick and clay as well as advanced ceramics used in abrasives and cutting tools.
The process of switching a machine from one part setup or process to another. Changeover is greatly reduced by laser cutting systems.
A cold cabinet or refrigerator that quickly cools fluids that are pumped to the laser cutter itself. A chiller is required for some laser cutters to offset the extreme heat generated by the beam.
A number designation given by the Food and Drug Administration (FDA) that indicates the hazard levels of lasers. The class of a laser ranges from I to IV, with IV being the most dangerous.
A class designated by the FDA for lasers that are considered non-hazardous. Class I lasers include laser printers and CD or DVD disk readers.
A class designated by the FDA for lasers that cause immediate skin and eye hazards when the beam is contacted or viewed directly. Class IIIb lasers include many industrial cutting lasers.
A class designated by the FDA for lasers that cause immediate fire, skin, and eye hazards from direct exposure to the beam or diffuse light. Class IV lasers include many industrial cutting lasers.
Computer numerical control. The use of computers and special programs to automatically carry out various machine operations. CNC systems for laser cutting commonly use hybrid, flying optics, and fixed optics systems.
A focus head with multiple nozzles that can be used for both laser cutting and welding. Combination heads are new and relatively rare.
To ignite or catch fire and burn. Reactive assist gases can combust when exposed to the extreme heat of a cutting laser.
computer numerical control
CNC. The use of computers and special programs to automatically carry out various machine operations. Computer numerical control systems for laser cutting commonly use hybrid, flying optics, and fixed optics systems.
CAD. A computer software program that aids in the automated design and technical precision drawing of a part, product, process, or building. Computer-aided design software is used to create a virtual model of a part.
A curved surface or part feature that is cut into a workpiece. Laser cutters can easily create contours.
A laser cutting method that creates a controlled crack by increasing tensile stress in a heat-sensitive workpiece. Controlled fracturing, or thermal stress cracking, works best on brittle materials like glass, crystal, and ceramic.
To meet at a single point. Light waves converge in the depth of focus.
A fluid used to decrease the temperature around machine components. The most common coolant for lasers is purified water.
The deterioration of a material due to a chemical reaction with another substance. Corrosion typically occurs when a material is exposed to atmosphere, moisture, or other substances.
A set of rules or limits that determine the characteristics or behavior of a laser cutter. Cutting parameters include cutting speed, number of passes, frequency, pulses per inch, and cutting power.
The rate at which a workpiece and a cutting laser move past one another. Cutting speeds determine how quickly unwanted material is removed from the workpiece.
depth of focus
A small region where light waves converge. In the depth of focus, light waves are sufficiently focused to produce a precise cut.
A small square of semiconductor on which a complete circuit is fabricated. Die are produced during stealth dicing.
Light that has been reflected off a non-mirrored surface, such as metal or glass. Diffuse light from powerful lasers can cause burns, fires, and permanent eye damage.
To spread apart from a single point. Light waves diverge after passing through the depth of focus.
The solidified waste that builds up on the top and bottom of a cut during some laser cutting operations. Dross is difficult to remove.
An air filtration system used to remove dangerous dust and fumes created by a laser cutter. Dust collectors commonly include air intake and exhaust equipment like fans, air filters, and a spark trap or arrestor.
A device attached to the end of a robot arm that allows it to interact with a part, component, or material. The end effectors of robotic cutting lasers are laser focus heads.
A product designed to be used directly by a consumer or directly in another manufactured product. End-use parts created by laser cutters require little or no post-processing.
A laser finishing process that adds permanent detail to a part by removing small amounts of material. Engraving usually requires the laser cutter to produce partial-thickness cuts.
A laser marking process that adds permanent detail to a part by selectively melting the surface of a workpiece and allowing the melted material to re-harden into a raised pattern. Etching can be used on any workpiece material that melts.
A metal that contains iron. The most common ferrous metals are cast iron and steel.
A fusion cutting method that uses ignited oxygen to produce more heat than the laser alone. Flame cutting, or reactive cutting, is best for thick workpieces and materials like steel that oxidize quickly.
A laser marking process that permanently changes the color of a part by heating it until small gas bubbles form. Foaming, or frothing, usually creates lighter colors where the gas bubbles remain after cooling.
The distance light waves travel from the lens to the point where they converge. Focal length is generally the same as the height of the lens on laser cutters.
The center of the depth of focus. The focal plane is where the laser beam is focused into the smallest possible focal spot and the laser beam is strongest.
The point at which light waves meet after reflection or refraction. Focal spots, or focal points, are created by a lens or a series of lenses.
To cause to meet at a single, concentrated point. Focusing laser light creates the smallest possible focal spot on a workpiece.
The mechanical assembly that contains the focusing lens, the cutting nozzle, and other components that control and project a laser beam. Focus heads may be stationary or may move above the workpiece, depending on the type of laser cutting system.
Food and Drug Administration
FDA. A U.S. federal agency that protects public health by ensuring drugs, cosmetics, food, and medical treatments are safe, effective, and truthfully labeled. The Food and Drug Administration also regulates all lasers in the U.S.
A laser marking process that permanently changes the color of a part by heating it until small gas bubbles form. Frothing, or foaming, usually creates lighter colors where the gas bubbles remain after cooling.
A potentially hazardous mixture of gases and particulate matter produced as materials melt or vaporize during laser cutting. Fumes can be managed by using laser cutters in well-ventilated spaces and regularly changing the air filters.
A laser cutting method that creates a kerf by heating part of a workpiece until it melts into a liquid and removing the molten material with forced gases. Fusion cutting, or melt and blow, processes are often used to cut metals.
A programming language that pairs address letters with numerical values to form commands. G code programming is used to direct laser cutter movements.
A type of laser that produces a laser beam by discharging electrical current through a gas lasing medium. Gas lasers include carbon dioxide lasers, helium lasers, and helium-neon lasers.
Consisting of multiple linear and curved shapes. Geometrically complex parts can be created by laser cutters quickly, accurately, and without the need for complex tooling.
Tight-fitting eye protection that completely covers the eyes, the sockets, and the surrounding facial area. Special goggles may be required to see and focus beams of invisible ultraviolet and infrared cutting lasers.
A source of danger or possible injury. Hazards of laser cutting include light radiation, fire, and dangerous fumes.
A type of personal protective equipment specifically designed to prevent hearing damage. Earplugs are the most common form of hearing protection.
HAZ. The area around a cut that is impacted by the heat of the cutting process. The heat-affected zone does not melt, but its mechanical properties are altered by the heat of cutting.
A part feature that forms a recess in the surface of a material. Holes can be produced by drilling, boring, reaming, tapping, and laser cutting.
A gas that does not chemically react with the substances it contacts. Inert gases, or non-reactive gases, include nitrogen, helium, and argon.
IR. A wavelength of light that is beyond, or longer than, red on the visible light spectrum. Infrared light is produced by some cutting lasers.
A miniaturized electrical network used to transmit electric power. A microchip is an example of an integrated circuit.
interchangeable focus heads
A focus head that can be removed from a laser cutter and replaced with another focus head to perform different laser tasks. Interchangeable focus heads enable laser cutting and welding on the same machine.
A meeting point where two or more parts are fused together. Permanent joints are created by welding.
A cut or opening created in a workpiece during a thermal cutting operation like laser cutting. Kerf sometimes refers to the width of a cut or the width of the material removed by a cutting process.
A cavity that forms in the surface of a workpiece when it is heated to its vaporization temperature. The keyhole allows the workpiece to absorb heat from the laser faster.
A device that generates an intense beam of coherent, collimated, monochromatic light that can be precisely aimed and controlled. Lasers are used for a wide array of manufacturing processes including metal cutting.
A thermal cutting process that uses a focused stream of coherent, collimated, monochromatic light to sever a workpiece. Laser cutting generally offers faster cutting speeds and more precision than other cutting processes.
A secondary laser process that improves the quality or appearance of a part. Lasher finishing processes include engraving, surface removal, and marking.
Goggles that protect against the intense light produced by lasers. Laser goggles are chosen based on the equipment and operating conditions in the workplace.
A welding process that uses a laser to heat base materials. Laser welding can sometimes be performed by modified laser cutters.
A liquid, gas, or solid material that produces a specific wavelength of light when it is exposed to and absorbs energy. Different lasing mediums produce different wavelengths of light.
A curved, transparent piece of material used to concentrate light waves to create a focal spot. The lens causes the light waves to converge.
lens cleaning fluid
A cleaning solution formulated for optical lenses. Lens cleaning fluid usually contains alcohol to promote fast drying.
A soft, non-abrasive, lint-free tissue paper used for wiping and wrapping lenses. Lens paper should be used to clean laser cutting lenses because it helps prevent scratches.
An adjustment ring that raises or lowers the lens in a cutting laser. Adjusting the lens screw changes the size of the focal spot.
Energy emitted in the form of waves or particles that induces a temperature change when absorbed by an object. Light radiation includes ultraviolet light, visible light, and infrared light rays.
A ray of electromagnetic radiation. Light waves are usually divided into the infrared, visible, and ultraviolet parts of the electromagnetic spectrum.
A laser finishing process that adds permanent details to a part or changes a part's color without removing material. Marking processes include etching, foaming, carbonizing, annealing, and thermal bonding.
mechanical cutting methods
A machining operation that uses single- or multi-point tools to remove material in the form of chips. Mechanical cutting methods include milling and turning.
melt and blow
A laser cutting method that creates a kerf by heating part of a workpiece until it melts into a liquid and removing the molten material with forced gases. Melt and blow, or fusion cutting, processes are often used to cut metals.
multi-axis CNC machines
A machining center that has four or more linear and rotational axes. Multi-axis CNC machines, or multitasking machines, combine the functions of a mill and a lathe.
neodymium-doped yttrium aluminum garnet laser
Nd:YAG laser. A solid-state laser that uses a crystal doped with neodymium to produce light. Neodymium-doped yttrium aluminum garnet lasers are some of the most common solid-state cutting lasers.
A colorless, odorless, tasteless gas that naturally exists in the atmosphere and is non-reactive. Nitrogen is a common assist gas for laser cutting, and it can also be used as a lasing medium or to improve the efficiency of carbon dioxide lasers.
Unwanted sound that is capable of harming hearing. Hazardous noise is usually loud, but some high-pitched noises can harm the ears without being heard.
A gas that does not chemically react with the substances it contacts. Non-reactive gases, or inert gases, include nitrogen, helium, and argon.
An element of a laser system that produces, redirects, intensifies, or alters light. Optical components include lenses, resonators, and mirrors.
optical fiber laser
A type of solid-state laser that uses thin, flexible strands of glass or plastic as a lasing medium. Optical fiber lasers produce more power and are more reliable than other solid-state lasers.
A material derived from living organisms. Organic materials contain carbon and include wood, paper, leather, and some plastics.
A chemical compound formed by oxygen combining with another element. Oxides can cause defects and cosmetic flaws if they are not removed from a workpiece.
To combine and chemically react with oxygen. Metals that oxidize include steel and aluminum.
A colorless, odorless, tasteless gas that naturally exists in the atmosphere and is reactive. Oxygen is a common assist gas for laser cutting.
A series of alphanumerical instructions that guides the movements of a laser cutter. A part program must be in G code to be read by laser cutters.
A cut that does not penetrate through the entire depth of a material. Partial-thickness cuts are used during engraving.
A single movement of a cutting laser across the workpiece, from one end of the cutting path to the other. Increasing the number of passes can allow a less powerful laser beam to produce the same results as a more powerful beam.
personal protective equipment
PPE. Any clothing or device worn to minimize exposure to hazards or prevent injury. Personal protective equipment for laser cutting includes laser goggles and heat-resistant gloves.
A lightweight material that generally has high corrosion resistance, a high strength-to-weight ratio, and a low melting point. Plastics, or polymers, are some of the most common manufacturing materials.
A procedure used to clean, improve, or otherwise finish a part after it has been manufactured. Post-processing procedures include abrasive finishing, heat treating, and painting.
The starting point of the X, Y, and Z coordinates for a part program. Program zero acts as a reference point for all part dimensions.
The number of pulse periods that occur in one second. As pulse frequency increases, the power of each pulse decreases.
pulses per inch
PPI. The number of laser pulses per square inch of workpiece surface. Increasing pulses per inch can increase cutting times but can also produce finer details.
A product development technique that uses processes like additive manufacturing and laser cutting to quickly create part models for a traditional manufacturing operation. Rapid prototyping allows engineers to quickly create a number of prototypes in a short time period, reducing lead time.
A laser cutting style that removes material point by point. Raster cutting is most often used for engraving and etching.
A fusion cutting method that uses ignited oxygen to produce more heat than the laser alone. Reactive cutting, or flame cutting, is best for thick workpieces and materials like steel that oxidize quickly.
A gas that chemically reacts with the substances it contacts. Oxygen is a reactive gas.
A tube that contains the lasing medium and, usually, two reflecting mirrors. The mirrors in the resonator, or resonant cavity, reflect light and amplify it into a powerful laser beam.
A group of components that can be programmed to perform a variety of complicated, repetitive tasks. Robotic systems are used to automate laser cutting processes.
A thermal stress cracking method that creates a groove or series of holes in a heat-sensitive workpiece to produce a controlled crack. Scribing works best on brittle materials like glass, crystal, and ceramic.
A special type of solid-state laser that produces a beam by discharging electrical current through a p-n junction diode. Semiconductor lasers, which are sometimes called diode lasers or injection lasers, are usually smaller and more precise and powerful than other lasers.
A thin, round slice of semiconductive material, such as silicon. Semiconductor wafers for electrical circuits are cut with laser cutters during stealth dicing.
A material that usually has little or no conductivity but has been doped to create a conductor. Semiconductors are critical materials for most electronic circuits and some cutting lasers.
The arrangement of a machine, workpiece, and workholding devices for a manufacturing operation. A laser cutter setup may include optional optical components like beam splitters.
A set of digitized programs and operating procedures. Software determines the actions or performance of a computer or machine.
The process of cutting thin wafers of semiconductor material into die for integrated circuits and chips. Stealth dicing can be performed with mechanical cutters or laser cutters, but laser cutters are more precise.
A laser finishing process that takes the top layer of material off a workpiece. Surface removal is usually used to clean oxidization off of aluminum and steel workpieces.
A force that attempts to pull apart or stretch a material. Tensile stress produces cracks during thermal stress cracking and scribing.
A laser marking process that adds permanent detail to a part by melting additional material onto its surface. Thermal bonding can join different types of materials together, such as plastic to metal or ceramic.
A cutting process that uses heat to remove material from a workpiece. Thermal cutting processes include oxyfuel, air carbon arc, plasma arc, and laser cutting.
thermal stress cracking
A laser cutting method that creates a controlled crack by increasing tensile stress in a heat-sensitive workpiece. Thermal stress cracking, or controlled fracturing, works best on brittle materials like glass, crystal, and ceramic.
A type of plastic that is permanently hardened by cooling. Thermoset plastics can char or burn during laser cutting.
3D. Having a length, depth, and width. Solid shapes are three-dimensional.
An unwanted but acceptable deviation from a desired dimension. Tolerances determine how much an object can vary from the desired dimension and still meet specifications.
2D. Having a length and width, but not depth. Flat shapes are two-dimensional.
UV. A potentially harmful wavelength of light that is below, or shorter than, violet on the visible light spectrum. Ultraviolet light is produced by some cutting lasers.
The gaseous form of a substance that is a liquid or solid at normal temperatures. The vapors from boiling workpiece materials can stabilize the walls of the kerf during vaporization laser cutting.
A laser cutting method that creates a kerf by heating part of a workpiece until it boils and turns into gas. Vaporization processes are often used to cut non-melting materials like carbon or thermoset plastics.
A laser cutting style that removes material along a continuous path. Vector cutting is most often used to create full-thickness cuts.
visible light spectrum
The portion of the electromagnetic spectrum that is visible to humans. The visible light spectrum includes light wavelengths from 400 nm to 720 nm and is usually described by color.
A measure of how much of the total electrical energy supplied to a laser system is output as optical energy. Wall-plug efficiency is expressed as a percentage.
The amount of electrical power a device requires in order to work properly. The wattage needed for a laser cutter depends on its wall-plug efficiency.
W. A unit of measurement for wattage or power. Watts are used to measure the power of a laser beam.
The distance between separate peaks of a light wave, which determines whether or not it is visible to the human eye. The wavelength of laser light is determined by the lasing medium and affects the laser's color, frequency, and power.
The erosion of material as a result of friction. Wear decreases the accuracy and precision of a tool.
Provided with a plentiful supply of fresh air. Laser cutters should only be operated in well-ventilated areas.
A component used to secure, support, and locate a workpiece during a manufacturing operation. Common workholding devices include chucks, collets, vises, and fixtures.
A part undergoing some type of manufacturing process. A workpiece may be subjected to cutting, welding, forming, or other operations.