When manufacturing functional parts and components, aluminum is most times the first metal that comes to mind. This metal is nonmagnetic and has an excellent strength-to-weight ratio which makes it suitable for many applications. Furthermore, aluminum conducts heat and electricity freely and is highly malleable and ductile.
There are different techniques you can use to process aluminum materials into parts that meet precise specifications. It is important to understand how each works to help you make informed decisions. This article contains the top ten metal fabrication techniques for aluminum. Read on to find out all you need to know about aluminum metal fabrication and determine the best technique for your project.
What is Aluminum Metal Fabrication
Aluminum metal fabrication is an act of turning raw materials into useful products and components. It involves all processes from cutting and bending to joining and assembling the parts. The process of aluminum metal fabrication begins with the design phase to have a pictorial representation of what you want the final part to look like.
You then prepare the aluminum workpiece by cleaning off all dirt and contaminants that can interfere with the process. The final step involves carrying out the various techniques and inspecting for quality. Aluminum is a popular choice for metal fabrication because of its many benefits. Aluminum is lightweight, ductile, and easy to handle.
10 Common Aluminum Metal Fabrication Techniques
There are different ways you can fabricate an aluminum workpiece. Each process has unique functions and serves different purposes. The following are the ten most common metal fabrication techniques you can use.
- Drilling
Drilling is one of the simplest ways of fabricating an aluminum workpiece. It involves creating round holes for fastener insertion or aesthetic purposes. You carry out this process using different types of drill bits. After selecting the right drill bit, you carefully create a pilot hole to prevent cracks. You then insert the multi-point cutting tool and rotate at a constant speed.
The final step involves deburring and making adjustments as needed. When drilling, it is important to apply lubricants and coolants. This will help prevent heat buildup and reduce friction that can cause mechanical damage. Furthermore, you should use a chip breaker and clamp the workpiece appropriately.
- Casting
Casting involves pouring molten aluminum into a mold that contains a negative impression of the final shape. As the molten metal cools and solidifies, it takes the shape of the mold creating a sturdy part. Casting is an economical way of mass-producing complex-shaped components. However, it can be time-consuming and is limited to smaller casting.
There are three main types of aluminum metal casting; sand casting, pressure die casting, and gravity die casting
Sand Casting
In sand casting, the mold you use is made of sand material like epoxy, plaster, concrete, and clay. You can not reuse the molds in sand casting because you have to break them up to remove the end product.
Pressure Die Casting
Pressure die casting can either be high or low pressure. In high-pressure die casting, you force the molten aluminum at a pressure above 1500 psi. Hence, the mold fills up quickly resulting in a higher production rate. Low-pressure die casting occurs at or below 15 psi and has a slower casting cycle.
Gravity Die Casting
Here, you fill-up the mold using no external force other than gravity. The mold is made of steel or cast iron and is reusable. Gravity die casting consumes a minimal amount of energy and produces dimensionally accurate parts.
- Punching
Punching is another method you can use to fabricate sheets of aluminum metal. It involves forcing a punch and die to create a hole through a workpiece. For punching to occur, the shear force you use must be greater than the shear strength of the aluminum alloy you are working with.
Punching is fast, efficient, and comes with low set-up costs. You can use it when manufacturing electrical enclosures, automotive components, and architectural features. However, this process generates a considerable amount of waste and can be noisy.
- Welding
Welding involves joining two or more aluminum parts together using heat and pressure. At high temperatures, the workpiece melts and the joint becomes molten. Thereafter, it cools down and solidifies creating a permanent bond. Note that you can also join aluminum with other metals such as steel, nickel, and titanium. However, you must use a suitable filler material to prevent different types of defects.
There are three main types of welding you can use for aluminum components; MIG welding, TIG welding, and laser welding.
MIG (Metal Inert Gas) Welding
You can also refer to MIG welding as gas metal arc welding (GMAW). This technique uses a consumable wire electrode to fuse components. MIG welding is easy to carry out and results in fewer start and stop actions.
TIG (Tungsten Inert Gas) Welding
The electrode here is a non consumable tungsten rod. To carry out TIG welding, an electric arc is formed between the electrode and the workpiece. As the arc melts the workpiece, you insert the electrode to produce a strong joint.
Laser Welding
Laser welding is an automatic or semi-automatic process that uses a highly focused beam of light to join aluminum parts together. This process is noncontact and has a low heat input. Additionally, you can use laser welding to create deep and narrow welds with minimal distortions.
- Milling
Milling is a common aluminum metal fabrication process. In milling, you gradually remove excess material from a workpiece using a rotatory cutter. As the tool engages and disengages, it results in a cutting action to produce complex shapes and geometrics. You can either carry out milling operations manually or use CNC machining to control the movement of the tools. CNC milling is more accurate and produces consistent results than its manual counterpart. Milling can be face milling or peripheral milling
Face Milling
You use face milling to remove material from the surface of the workpiece by placing the tool perpendicularly to it. This technique is ideal for flat surfaces and when you want to achieve smooth finishes.
Peripheral Milling
Peripheral milling describes the process of cutting excess material from the outer surface of the aluminum workpiece. The tool is parallel to the workpiece and can produce complex shapes with a high degree of accuracy.
- Grinding
The cutting tool here is an abrasive grinding wheel. To carry out the aluminum metal grinding operation, you first select the appropriate abrasive wheel. The type of aluminum alloy and the desired surface finish will influence the selection process.
You then mount the workpiece and remove material in a controlled manner till you get the final form and finish. Grinding produces a minimal amount of heat and does not form burrs. Furthermore, this process is accurate and you can use it for applications with tight tolerance requirements.
- Riveting
Riveting is another way of fabricating aluminum metal parts. It involves the use of different types of rivets to fasten two or more components together. The first step in riveting involves drilling a hole based on the size of the rivet. You then insert it carefully and deform the tail using a hammer.
There are various types of rivets you can use with the most common being solid and blind rivets. They are made using copper, steel, brass, stainless steel, and aluminum. Riveting is essential when assembling car body panels, sports equipment, and aircraft structures. However, rivets add to the overall weight of the components.
- Cutting
Cutting is a subtractive aluminum metal fabrication technique. It describes the process of removing extra material from a workpiece to get the desired shape and size. Cutting is a fast process and is suitable for both small and large-scale production. It is versatile as you can cut many types of aluminum alloys.
There are different types of aluminum metal-cutting processes. Some require shear force while you need heat to carry out others.
Mechanical Cutting
This type requires a sharp cutting tool to press against the workpiece and divide it into multiple parts. Sawing, shearing, turning, and milling come under mechanical cutting. The cutting tools are easy to operate and they do not cause thermal distortion.
Thermal Cutting
Thermal cutting uses heat to melt and vaporize through an aluminum workpiece. Examples of thermal cutting processes include laser cutting, plasma cutting, and oxy-fuel cutting. Thermal cutting techniques can cut complex shapes with high precision. However, they can form heat-affected zones which can affect the functionality of the part.
- Extrusion
Extrusion is the process of forcing aluminum metal through a die to shape it into a desired cross-sectional area. It is best when manufacturing long components such as bars and tubes. Extrusion can either be direct or indirect
Direct Extrusion
The molten metal flows in the direction of the feed of the punch in direct extrusion. It requires a higher force to operate and produces parts at a fast rate.
Indirect Extrusion
Here, the molten aluminum flows against the movement of the plunger. You can use indirect extrusion for more complex shapes such as T and L sections.
- Etching
Etching is the removal of excess material from the surface of an aluminum workpiece using chemical or photochemical reactions. Etching is accurate and you use it for delicate applications.
Chemical Etching
In chemical etching, you use solutions which can be acidic or basic to react with the part’s surface. This etching solution dissolves the metal to create the desired shape and design.
Photochemical Etching
This process employs light and chemicals to etch a part. The photochemical etching does not result in mechanical stress and is suitable for thin materials. However, it comes with limited depth penetration and can be time-consuming.
Conclusion
Aluminum metal fabrication requires being more than just familiar with various techniques. You must be able to choose the right process for your part. There are some factors you should consider during the selection process. Consider the shape, size, and required level of precision you need. The desired surface finish, lead time, and budget will also influence your decision.
This article has explained what aluminum metal fabrication is and the top ten techniques you can use to create detailed designs and useful structures. To make things easier, you can use the services of a third party manufacturer. Simply search for metal fabrication near me and reach out to a company that meets your needs.
