CNC machining can produce parts from almost any metal or plastic. This being the case, there’s a huge range of materials is available for parts made via CNC milling and turning. Since this method works with a wide range of materials, including metal, fiberglass, and wood, it's easy to choose one that's adequate for the project but not the best option. In this piece, we'll discuss essential factors to remember when selecting a material for CNC machining and provide an overview of some popular choices.
These are some of the factors to consider before choosing the right material for your CNC machining project:
Heat resistance directly impacts materials' potential to withstand high temperatures without significant deformation or damage. During the CNC machining process, the substance goes through several heating and cooling processes, especially when it is cut, drilled, or milled. Materials that are not heat resistant may experience thermal expansion, warping, or cracking due to these processes.
Choosing CNC materials with excellent heat resistance can facilitate better machining and lower production costs. A material with high-temperature resistance also allows for deeper and faster cuts. This results in faster machining rates and less tool wear.
The choice of CNC machining material relies on the final product's intended use since different materials have different levels of heat resistance. Materials like aluminum and copper are ideal for thermal management, heat sinks, and thermal management due to their excellent thermal conductivity. However, stainless steel and titanium are perfect for aerospace and medical uses because of their high melting points and corrosion resistance.
Part weight is essential to guarantee cost-effectiveness, performance, and manufacturability. Heavy parts require more material, and this increases production costs. Additionally, manufacturing heavier parts might necessitate bigger, more powerful CNC machines, raising costs and lengthening turnaround times. For this reason, selecting a material with a reduced density, like aluminum or magnesium, can aid in reducing the part's weight and lowering production costs.
Component weight can have an impact on how well the finished product performs. For instance, in aerospace uses, a component's weight can affect fuel efficiency and total performance. Reducing weight can boost acceleration and handling in automotive benefits and fuel efficiency.
When selecting CNC materials, it's essential to consider the machining surroundings. Various mechanical factors, such as cutting speed, tool type, and coolant, affect how different materials respond. Some of the variables that make up the machining environment include temperature, humidity, and the presence of contaminants.
For instance, if the temperature during machining rises too high, some materials may be more likely to chip or split, while others may experience excessive tool wear. In cases like this, specific coolants or lubricants may be required to lessen heat and friction during machining. However, they might not work well with some materials and cause corrosion or other types of harm. Therefore considering the machining environment reduces costs and improves productivity and quality of the final products.
The surface finish affects the performance and appearance of the final product. For instance, a part with a rough surface experiences increased friction and may cause premature wear and failure. A part with a smooth surface finish will experience less friction, leading to better efficiency and a longer lifespan. The surface finish also greatly contributes to the appearance. A polished surface finish enhances a part’s appearance and appeals to customers.
Therefore, it is essential to consider the end product's surface finish requirements when selecting materials for CNC machining. Some materials are simpler than others to process to a smooth surface finish. For instance, it's relatively easy to machine metals like brass and aluminum to a smooth surface. However, materials like fiberglass and carbon fiber can be quite difficult to machine, and having a smooth surface requires specialized techniques and tools.
The application is the main thing that determines the perfect material for your CNC machining project. However, the other reasons discussed above are essential in deciding the final CNC material. Other factors affecting the application are material machinability, chemical reactivity, adhesiveness, material availability, fatigue life, etc.
Various materials' hardness, tensile strength, and flexibility are different. These characteristics affect a material's performance under any circumstances and establish the material's suitability for various uses.
For instance, aluminum and copper would be appropriate materials if the finished product is meant to be used in a high-temperature environment. While copper is the best choice because of its high resistance to heat and height thermal conductivity.
There are different reasons why you should consider the budget. One reason is that the material price can depend on the quantity and type needed. Plastics or hybrid materials may be less expensive than some high-grade metals, which can be costly. Setting a spending limit for materials will enable you to concentrate on options within your means.
Second, the expenses associated with CNC machining can be high and time-consuming. The sort of material, part complexity, and necessary machinery all affect how much it will cost to machine something. The overall expense of production can be reduced by selecting materials that are less expensive to a machine.
Last but not least, choosing materials that fit within your budget can affect the quality of the final result. Less expensive materials may need to be more robust or prone to flaws. Setting a budget and selecting higher-quality materials will guarantee that the final product is solid and high quality.
These are a few of the common materials you can use for your CNC machining project:
● Aluminum
Aluminum alloys are lightweight, simple to machine in large quantities, and have excellent thermal and electrical conductivity. They are also naturally rust-proof. The most common type of aluminum used in CNC machining is the all-purpose aluminum alloy 6061. Automobiles, bicycles, sporting equipment, and other recreational products are made from them. Although it is very machinable, it can be more expensive than other metals and doesn't hold up well when exposed to chemicals or saltwater. Aluminum 7075 is an improvement over 6061. It is the strongest, widely available aluminum alloy, perfect for aerospace frames and high-performance recreational equipment.
● Stainless steel
Alloys made of stainless steel are firm and resistant to wear corrosion and distortion. Sulfur is added to 303 stainless steel to enhance machinability, but there are a few drawbacks that designers should be aware of. 303 cannot be cold-formed, heat-treated, or welded. Despite this, 303 produces top-notch nuts, bolts, non-marine components, shafts, and gears.
The non-magnetic, all-purpose steel known as 304 stainless steel for CNC machining is renowned for its toughness. Like 303, it is easily machinable and impervious to corrosion, but it can be welded. Kitchen utensils, tanks and pipes, architecture, and many other items are among the many consumer and commercial uses for 304.
The difference between 303 and 304 is that 304 stainless steel contains molybdenum. It is one of the few stainless steels that is marine quality, robust, and weldable. However, you should test the raw material to verify the properties of the steel you want to use because it's difficult to distinguish between stainless steel by sight alone.
● Titanium
Titanium is commonly used to make parts for the aerospace and military industries because of its high strength, toughness, and corrosion resistance. This substance is also appropriate and biocompatible for use in the production of medical devices.
The commercial form of titanium is more costly than any other metal, polishes poorly, and performs poorly as an electrical conductor. You should know that titanium requires specialized cutters and is difficult to machine.
● Nylon
Nylon is commonly used in place of metal in many CNC-produced components. It is a multipurpose, low-friction thermoplastic. This material is quite elastic for being stiff, strong, impact-resistant, and chemical-resistant. Engineers can easily manipulate nylon to achieve the desired properties because it reacts well to additives and fillers.
Nylon is frequently used in various products, such as electrical molding, cloth, gears, food packaging, and automobile parts. However, it readily absorbs dampness, which may adversely affect a part's dimensional stability.
With the development of material science, careful selection has become increasingly crucial for CNC milling. Ares Prototyping offers a wide selection of materials, from premium metals to high-quality plastics, and specializes in CNC manufacturing services, such as CNC milling and turning. With the help of our skilled staff and 5-axis machining skills, we can offer our clients unmatched precision and quality.
We are committed to delivering top-notch customer support and assisting our clients in saving money and achieving their objectives. Our technical team is accessible to help you choose the ideal materials for your project and can offer professional guidance without cost. Whether you require specialized CNC-machined components or have a custom project in mind, we’re here to assist you.