Are you wondering which material and how it can be processed by a CNC machine? CNC is a very precise and repeatable manufacturing process used for prototyping and producing parts. It is also subtractive, meaning it uses computer-controlled cutting tools, such as drills and lathes, to cut material from blocks. The result is professional-quality components suitable for mechanical use.
Versatility of materials
One of the biggest advantages of CNC machining is its material versatility. This is because the process can utilize materials such as aluminum and steel alloys, as well as various structural metals. It is also used for cutting high-quality plastics. Many of these are machined by CNC to achieve various finishing options. In most cases, such a wide range of options provides such flexibility. However, there are so many CNC machined materials that can also be used, which creates an additional dilemma about making your project ultimately profitable. In this article, we will discuss the various properties of raw materials in terms of CNC machining and factors to consider before choosing a specific CNC material. Read on to find out how to make the best possible product choice in a simple way.
How to choose the right semi-finished product for CNC machining?
Considering the wide range of materials available for CNC machining, there is likely more than one raw material suitable for prototyping or production tasks. However, finding that one, perfect element for a given CNC machining project is the user's first task. It's worth asking yourself: Do you need a metal with excellent mechanical properties, such as titanium? Or perhaps speed is a priority, leading to the choice of easier-to-machine materials, such as aluminum or plastics like Delrin? Or maybe you just want to receive a machine-built prototype at the lowest possible cost? Below is a sample list of additional considerations to answer before choosing CNC materials for your project:
What will the part be used for?
Just as CNC machining can process various materials, it is also suitable for producing a variety of parts. Therefore, the use of appropriate semi-finished products is definitely the first thing to consider when choosing CNC raw materials. This is because the application will help determine the properties that the CNC material must have. For example, parts that require insulating properties will prefer plastic. However, due to tensile strength, the choice of metal may be more advantageous. Although this example may seem simple, most CNC materials needed for part production must have multiple properties.
What are the operating temperatures of the parts?
Another important factor to consider before making the final choice is the operating temperature of the environment in which the component will operate. This is because the melting temperature of the CNC material used must be higher than the operating temperature. Otherwise, the structure of the part may change. It is also necessary to ensure that the CNC processed raw material is resistant to extreme temperature changes. Some materials can withstand these value jumps, but others may show structural changes over time. Another reason to understand the material's tolerance to operating temperatures is whether it can withstand the heat generated by CNC machining.
Place of use for CNC parts
Working conditions of parts vary depending on the location. For components used indoors, the temperature and humidity they will be exposed to in the working environment can be precisely determined. However, in outdoor environments where the weather is uncontrolled, it is recommended to use materials resistant to moisture and rust, while maintaining their structure. In addition, extreme changes in weather conditions in the outdoor environment can distort the structure of individual CNC materials. Of course, it is not always possible to find a raw material that will best meet all criteria. The strongest ones intended for processing are rarely the cheapest. In addition, choosing higher strength may result in reduced chemical resistance or other properties. However, after answering these questions, we should be able to identify the most important elements of the specification that our chosen CNC processing material must have. The next step is to identify CNC materials that may match our ideals.
Overview of Various CNC Materials
The quickest and easiest way to determine the best and most suitable material for CNC machining is to consult with an expert. After familiarizing themselves with the outline of your project, they can assist you in making decisions about raw materials, implementation processes, and based on your goals, budget, and timeline. However, if you want to get a shortlist of potential CNC machining materials in advance, check out the available options. From universal aluminum alloys to specialized construction materials. Here are some materials that are compatible with CNC machining:
Cast metals in CNC
One of the main reasons for the popularity of CNC metal casting is its compatibility with various types of them. Precision parts for CNC machining can be made from different materials. Some of them are listed below.
Stainless steel
Stainless steel (SS) is by far the most common type of metal used in precision CNC manufacturing. Valued for its corrosion resistance and durability, this raw material is found in everything from surgical equipment to electronics and beyond. This metal is known for its versatility, durability, and lightness, which extends its application in various industries.
Carbon Steel
This is another popular metal for precision machining. It comes in various forms and can be selected according to the requirements of the application. Carbon steel was chosen for its affordability, durability, long service life, and environmental friendliness. It is also known to provide a high level of machinability and weldability while maintaining high strength.
Aluminum alloy
Aluminum alloys are probably the most popular choice for CNC metal casting. Due to their high machinability, corrosion resistance, and light weight, they are widely used in the production of car parts, food containers, bicycle frames, aircraft parts, and many other fields.
Nickel-based alloy
Similar to stainless steel, nickel-based alloys are preferred due to their excellent resistance to corrosion. Nickel combines with zinc, iron, manganese, copper, and chromium to achieve the desired effect. High-nickel alloys are often used in applications related to chemical processing.
Copper Alloy
Copper-based alloys have high resistance to corrosion, making these metals an excellent choice for long-term use. Brass is one of the most popular copper-based alloys. It is considered one of the easiest and most cost-effective metals to use in CNC metal casting services and is chosen for the production of complex parts that require complicated functions.
White iron
It is known for its high compressive strength and excellent abrasion resistance. Moreover, it retains plasticity for a certain period of time after exposure to extreme temperatures. Some types of white cast iron contain a high level of chromium to further improve performance in high-temperature applications.
Gray Iron
This is a type of iron known for its appearance and color due to the cracks of graphite in the material. Depending on the type of this metal, different levels of strength and machinability can be achieved. Gray iron is used where rigidity is more important than the tensile strength of the element, e.g. electrical boxes, decorative castings, pump housings, etc.
Spheroidal cast iron for CNC
This raw material has a higher tensile strength than gray iron, which allows it to be used in many different market segments. Commonly known as ductile iron, it is known for its elongation, wear resistance, hardness, and fatigue resistance due to the spherical structure of the metal.
Copper sheet for CNC
In addition to aluminum and steel, metals such as brass, copper, titanium, and zinc can be processed, giving engineers a wider range of physical properties of parts. For example, copper is an excellent conductor. This feature makes it suitable for the production of electrical parts.
Acetal Plastic
The CNC machines are also capable of cutting plastics. In most cases, these raw materials may be preferred due to costs, electrical insulation, or for other reasons. When the final part is produced by injection molding, plastic is often the appropriate material for creating prototypes.
Summary
After reading this article, it becomes clear that CNC machining is a manufacturing process that can be adapted to many different applications in diverse business fields. Due to this versatility, you may one day find yourself facing the choices described above, and later grappling with every aspect of the manufacturing process. Choosing the right material is an extremely important factor that affects the entire production process. Furthermore, it should be remembered that tools from machines during production can generate different temperatures on the surface of materials. For this reason, when creating milling with a CNC device, let's choose materials so that their production does not distort them.