Can Laser Cut Metal
Laser cutting is a precision manufacturing process that uses high-power lasers to cut and shape materials. This technique comes with unmatched accuracy, speed, and flexibility. While laser cutting is commonly associated with nonmetals, technological advancements have made it possible to cut through both thick and thin metal sheets.
Can laser cut metal? The answer to this question is a resounding YES. With the right equipment and parameters, the process of laser cutting metal is relatively easy. This article will be your guide on everything laser cutting of metals. It will explain how to efficiently cut metals using a laser beam, the advantages of laser cutting metal, and considerations to get the best result.
Can Laser Cut Metal
Yes, lasers can cut metal efficiently. Laser cutting is one of the most recommended metal-cutting processes you can use for a metal workpiece. Different types of lasers, most especially fiber and CO2 lasers, are suitable based on the material properties and thickness level. Laser cutting is a noncontact operation that gives high-quality and accurate cuts. Laser metal cutting works in a simple and straightforward way. It involves focusing a laser beam to cut through materials.
The first step in laser metal cutting is to create a digital design of what you want the final part to look like. You then generate the laser baser in a resonator by exciting a gain medium. Thereafter, the laser beam is amplified and focused using a lens to produce a localized high-energy point. By directing the laser beam at the material, it vaporizes and melts it to create the desired shape. Simultaneously, an assist gas, usually argon or nitrogen blows the melted metal away from the cut zone. You then remove residual debris and carry out necessary post-processing operations.
What Kinds of Metals Can Be Laser Cut
Laser cutters work with many grades of metals and alloys. Let’s explore the common metals you can cut and the properties that make them suitable for laser cutting.
Aluminum
Aluminum is one of the most widely used materials when laser cutting. It is lightweight, ductile, and nontoxic. Aluminum has a high thermal conductivity and transfers heat efficiently which reduces the incidence of distortion or warping. However, you should be careful when using lasers on an aluminum workpiece because of its high reflectivity.
Stainless Steel
Laser cutting also works well with the different types of stainless steel. With the proper laser parameters, it is easy to cut austenitic, martensitic, and ferritic stainless steel. They are durable, corrosion-resistant, and have a high tensile strength. Additionally, the various grades are easily machinable and you can cut at a fast speed to create burr-free edges.
Mild Steel
Mild steel is another metal suitable for laser cutting. This metal has a low carbon content with a high percentage of iron. Mild steel is ductile, easy to cut, and has a low reflectivity. Furthermore, it dissipates heat efficiently and produces a consistent cutting result. However, you should control the amount of heat input when cutting mild steel to prevent burning the edges excessively.
Titanium
You can also use laser cutters to accurately fabricate a titanium workpiece. Titanium is biocompatible and durable with an excellent strength-to-weight ratio. This metal has a moderate thermal conductivity and is nonmagnetic. Hence, the generated heat is localized and you have precise control over the cutting process because of the absence of a magnetic field.
Brass
Brass is a metal alloy that is made up of copper and zinc. Lasers can cut through a brass workpiece with a high level of accuracy to create intricate designs. However, brass’ high reflectivity poses a challenge when cutting as the laser beam gets reflected into the cutter. To minimize the effect, you can apply anti-reflective coatings on the brass workpiece.
Copper
Copper is a versatile metal used across manufacturing industries. Its antimicrobial properties make it stand out. Copper kills microorganisms and other pathogens that come in contact with it. It is easy to work on copper and this metal makes laser cutting easy. Fiber lasers are suitable when cutting intricate patterns on copper sheets that are 10mm thick or less.
Advantages of Metal Laser Cutting
There are many benefits you stand to gain from using lasers to cut metal parts. The following are some
Non Contact
The laser beam does not have to physically touch the workpiece for it to cut through. You cut using just energy and gasses. This feature makes laser metal cutting suitable for delicate applications because there is little to no incidence of material contamination. The non-contact feature also reduces the risk of mechanical damage and deformation.
Automation
Laser metal cutting is fully automated and computer-controlled. The machine can run unattended for hours after executing the operation. This gives you time to carry out other important and time-sensitive operations. By maximizing time and resources, laser metal cutting improves efficiency and enhances productivity.
High Speed
The speed of laser metal cutting is second to none. You can cut a metal at a speed of up to 10 m/min depending on the metal in question and the power of the machine. This makes it ideal for mass production of parts. Furthermore, laser metal cutting reduces cycle time and gets your products to market on time.
Low Heat Input
Unlike many other thermal cutting processes, laser cutting uses a low heat input to function. The energy is concentrated to a single point and does not affect the surrounding material. Furthermore, this process preserves the properties of the metal and prevents the build-up of stress as a result of excessive heat. Additionally, there is no incidence of thermal damage and distortion.
Reduced Finishing Requirements
With laser cutting, you will get a high-quality finish and smooth edges. One of the reasons for this is that laser metal cutting does not use physical tools that can cause marks and imperfections. This reduces the need for deburring and sanding. As a result, laser metal cutting ensures faster production and less material waste.
Factors Affecting Laser Cutting of Metals
Though the process of laser cutting metals seems pretty straightforward, some factors can affect your final result. Let’s explore these factors
Laser Type
The type of laser you are using plays a huge role in the laser metal-cutting operation. Fiber and CO2 lasers are the most suitable when working with metal materials. Fiber lasers have a high power density and produce excellent beam quality. Furthermore, it operates at a wavelength of around 1.06 micrometers which is well absorbed by most metals. In certain instances, you can also use a CO2 laser cutting system for thin and nonferrous metals.
Laser Parameters
You have to properly optimize the different laser parameters based on the properties of the metal material. Using the right power, wavelength, pulse duration, and frequency results in significant differences. Too low laser power and frequency will lead to incomplete cuts. However, you may experience overheating or burning when the power, pulse duration, and frequency are higher than required.
Cutting Speed
It is important to also adjust the cutting speed based on the metal thickness during fabrication. Using a high speed will give you jagged edges while a low one may increase heat input. For thin metal sheets, you should use a higher cutting speed to avoid creating HAZ. On the other hand, stick with a lower cutting speed for thick metals for even penetration and deep cutting.
Assist Gas
Assist gas is an essential part of metal laser cutting. You need to use inert gasses such as nitrogen, argon, compressed air, helium, and oxygen to remove the molten metal and for proper heat dissipation. The type of gas you are using depends on the metal in question. Oxygen is better for carbon steel while nitrogen works fine with aluminum and stainless steel. Go for argon gas when working with reactive metals like titanium.
Material Preparation
The way you prepare the surface of the workpiece before cutting has a great influence on your performance. You must clean off dirt, debris, moisture, and other contaminants. When present, these contaminants can absorb a significant amount of the laser beam which reduces the efficiency of the process. Proper cleaning is important to ensure the metal absorbs all the light for more precise and defect-free cuts.
Other Alternatives for Metal Cutting
In addition to lasers, there are other ways you can accurately cut a metal part. Each technique is carried out differently and has unique advantages and disadvantages.
CNC EDM Cutting
CNC electrical discharge machining is a noncontact process that uses electrical sparks as the cutting tool. The process of CNC wire EDM involves submerging the workpiece in a dielectric fluid and bringing an electrically conductive wire close to it. When the workpiece and wire are near each other, a series of electrical sparks are generated.
The sparks jump the gap and produce heat and evaporate a part of the workpiece. Deionized water then flushed away the particles. CNC EDM cutting is accurate and you can use it to create fine designs. However, you can only work with conductive materials like aluminum, titanium, and steel.
CNC Plasma Cutting
CNC plasma cutting is another important process you can use for metal fabrication. Here, you employ an electrically conductive and ionized gas-like substance called plasma to cut a metal workpiece. CNC plasma cutting works by creating an electric arc between the electrode and the workpiece.
As the gas comes in contact with the arc, it is converted to an accelerated jet of hot plasma. The plasma melts the material in a predetermined location for a cutting action. Just like CNC EDM cutting, plasma cutting is only suitable for electrically conductive metals that are less than 150mm thick.
CNC Waterjet Cutting
CNC waterjet cutting is a cold process that cuts metal pieces using high-pressure water steam. You carry out CNC waterjet cutting using pure water and abrasive materials such as garnet, silicon carbide, or sand. CNC water jet cutting gives smooth edges devoid of defects and burrs.
Because it is a cold-cutting process, you don’t have to worry about thermal distortion and heat-affected zones. Furthermore, CNC waterjet cutting is fast and you can achieve tolerances within 0.003 inches. This improves operational efficiency and boosts overall productivity.
Conclusion
Laser cutting is a versatile process that continues to transform the manufacturing industry. You can use this technique when fabricating metals and alloys. For a smooth cutting operation, you have to use the right laser technology, adjust important parameters, and properly prepare the surface of the workpiece. To avoid costly mistakes, consider using a custom laser-cut metal fabrication service provider. Reach out to make your inquiries and clear all doubts.
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