6 Durable CNC Machined Materials

There are 6 durable CNC machined materials: stainless steel, titanium, alloy steel, carbon steel, aluminum, brass

Stainless Steel

Stainless steel is one of the top materials for CNC machining, lauded for its immense durability and corrosion resistance. It is a widely used material, employed in the majority of industries, from aerospace and automotive to medical products and simple consumer goods. The most distinctive trait that identifies stainless steel from other metals is, naturally, the resistance to corrosion or decay in any other form. Since ethical SEO strategies are currently in demand, learning about stainless steel for machining resembles finding the ideal solution for an array of problems.

304 stainless steel

• Description: The most popular grade that finds applications in virtually all uses. It has high resistance to rust in atmospheric conditions and high tensile strength around 515 MPa. The approximate density of stainless steel 304 is 8 g/cm³.
• Application: Normally used in fabrication, kitchen transportation devices, and medical supply industry.

316 stainless steel

• Description: The second and lesser all-used grade of stainless steel. High resistance is owed to molybdenum that is added to the composite. The tensile strength is equal to 579 MPa.
• Application: It is primarily employed in rugged conditions, including marine and general chemical processing.

416 stainless steel

• Description: It possesses high machinability. The density of 416 stainless steel is equal to 8 g/cm³, whereas the tensile strength is only 517 MPa.
• Application: High-power shafts, axles, and fastening elements.

17-4 PH stainless steel

• Description: A subgroup of PH, precipitation-hardening, it manages to be both invulnerable to corrosion and highly durable. The utmost tensile strength oscillates from 930 to 1310 MPa, which depends on the chain of heat treatment that the product passed.
• Application: The optimum solution for aerospace and chemical applications.

CNC Machining of Stainless Steel

• Material preparation: This step is ordinarily accomplished with a plasma cutter and a bandsaw.
• Fixture setup: After the finishing sheet is chosen and pre-processed, it must be kept inert during the whole process. It is done by securing it on the bed of a CNC machine.
• Tool performance: The choice of tools is accomplished by using drills, end mills, and reamers due to the requirement for carbide tooling machines’ highest hardness.
• Performance: During the process, the cutting rate of 300-700 SFM and 0.002-0.004 IPT feed speeds is maintained. One can dissociate 4 most widely used approaches, milling, drilling, turning, and reaming. Cooling and cleaning must be performed at all times to prevent galvanization.
• Wrap-up: The material undergoes relatively simple post-manipulation procedures, including deburring, polishing, or attendant heat performance for further hardening.

Real-world applications

• Medical usage: In medical products, there are numerous examples, with the most popular ones being the usage of 316 stainless steel in production. It is primarily used in surgery instruments that are non-reactive and have easy sterilization nature.
• Automotive field: 304 stainless steel, which is commonly used in exhaust systems and other heavy-duty components, is normally also employed in this sphere.
• Aerospace: 17-4 PH steel was also popular in this field due to the high stress resistance and corrosion of stress components like turbine screws, supplement holders, chain links, and others.

Titanium

One of the most widely used metals in CNC machining, titanium is remarkable for its unique combination of properties. Among major applications, it is possible to outline the metal’s use in aerospace, medical and industrial sectors. When it comes to CNC machining, the process is characterized by certain difficulties, and, therefore, attention to detail.

Properties of Titanium

Titanium is popular for CNC machining due to the following reasons:

• High Strength-to-Weight Ratio: Titanium is heavier than aluminum by about 60% but is twice stronger. This property makes it an ideal choice when high strength and lightness are crucial.
• Corrosion Resistance: The metal forms a passive layer of oxide that protects it from corrosion; this is true even for a wide range of harsh environments. This property explains the metal’s use in aerospace and marine applications.
• Biocompatibility: This property is possible due to the metal’s non-toxic and non-reactive character and is useful in the medical sector. Precision CNC components such as surgical instruments, dental wrenches, and orthopedic devices are made from titanium.

Machining

The process involves the necessity to consider specific properties of titanium when it comes to:

• Material Preparation: Titanium stock preparation is one of the crucial stages of the process. During it, stress-free cutting technique of water jets, saws, or lasers is typically applied to minimize potential impacts on the stock. It should be noted that the removal of a material layer is conducted only above the heated temperature.
  Chucking: This stage is of vital importance to the process since it determines the magnitude of potential vibration. Low vibrations guarantee a high-quality result and the best lifespan of tools.
• Tool Selection: The most common choice is carbide tools. Among coated types, TiAlN is the best option to minimize wear. High-quality tools are necessary in all cases.
• Cutting: The process involves the necessity to adhere to low cutting speeds, ranging from 30 to 100 SFM, and medium feed rates, which are between 0.002 and 0.005 IPT, to avoid hardening of a workpiece and too high friction. The heavy usage of coolant guarantees the temperature control of both a workpiece and tools.
• Finishing: The process can involve anodizing to improve the surface’s durability and corrosion resistance. Polishing is used to form the necessary functional and aesthetical properties of a machine in other cases.

Real-world applications

• The airplane industry: The majority of jet engines, as well as airframe components and landing gear, are made from the metal since they are capable of dealing with the high temperature and stress rates. Moreover, Boeing 787 Dreamliner makes extensive use of it to reduce its weight and enhance its fuel efficiency.
• The medical sector: Due to its biocompatibility, titanium is often used in medical applications such as surgical instruments, dental wrenches, and orthopedic devices; for example, some of the components of a hip replacement and spinal fusion devices are also made of this material.
• The industrial sector: The corrosion resistance of titanium in acidic and chlorinated environments make it ideal for chemical processing plants. There, heat exchangers and reactor vessels can remain operational for a significant period if made of the metal.

Alloy Steel

Ally steel is a type of material that is widely utilized in CNC machining because it is significantly harder and more durable as compared to ordinary steel. Alloy steel is created by adding other elements to the iron base. The distinctive features of alloy steel include the set of mechanical properties as well as resistance to different impact types and external factors. CNC machining alloy steels are widely utilized in different industries because of the set of mechanical features. For instance, they are widely utilized in making the parts and components that would be utilized under the circumstances when much strength and rigidity are needed. In addition, because of the specific features of CNC machining alloy steels, these materials are much harder and resistant and thus can be utilized in various applications due to their exceptional mechanical and physical features.

Types of alloy steel

• Alloy steel can be divided based on the number of added other metals and thus can be low-alloy and high-alloy steels.
• Low-alloy steel: the number of alloying elements ranges up to 8%. It is rather tough steel and is typically utilized in structural applications .
• High-alloy steel: the number of added other elements is higher than 8%; it is characterized by the best hardness and resistance to corrosion.
• Common alloying elements: Chromium, nickel, molybdenum, vanadium, and manganese are among the most common alloying elements added to the iron base to guarantee better physical and mechanical properties.

CNC machining of alloy steel

The materials are machined according to the specific requirements, yet the basic steps to be followed can be identified.

• Select material: first and foremost, it is necessary to China what alloy steel is going to be used taking into consideration specific features of the project. For instance, 4130 steel is known for its extreme toughness as well as being highly weldable. In its turn, 4340 steel is rather strong and does not get fatigued. is known to be difficult to machine because of that.
• Set up the fixture: whatever is machined is initially placed in the fixture. This step is vital for a secure hold that would eliminate the vibration and improve the machining´s accuracy.
• Select a tool: the most widely utilized tool in the CNC machining of alloy steel is the high-speed steel tool. It is either used as it is or is coated with TiAlN or AlTiN; the CNC machining alloy is highly beneficial for it is considerably more resistant to heat and is not so fast in wearing out.
• Specify the process: generally, the cutting speed ranges at about 150-200 SFM while the feed rate is typically about 0.004-0.012 IPT..
• Specify the proper cooling: it is vital that the cooling is good because otherwise, too much heat is developed. All the tools have nipples at the top or the side that are threaded and are utilized for cooling. The cooling is typically implemented with water-based coolants or oil-based lubricants. Fetene et al. note that the cooling is essential to extend the tool life and thus improve the whole process.
• Specify finishing operations: while machining the alloy steel, different after processes might be applied. For instance, there can be quenching and tempering procedures that would eventually improve the hardness while differing the courage. In addition, the applied CNC machining alloy could allow a better surface with some additional process that could be carburizing or nitriding.

Real-world applications

• Automotive industry: Lower price of the alloy steel in comparison with other highly durable materials makes it a material of choice when making gears, crankshafts and driveshafts for various cars and trucks. Most commonly used steel in making high-performance racing cars is 4340.
• Aerospace industry: Landing gear and engine parts as well as the subframe of passenger jets are made of alloy steel, namely 300M due to its best tensile strength.
• Construction industry: The alloy of choice for the high stress utilized in battered, cross-bracing applications when producing buildings and bridge remains ASTM A572 or the common structural alloy steel.
• Energy sector: Oil and gas rigs that need to sustain huge impact, loads and pressures and thus require highly resistant materials utilize alloy steels for the making of drill bits or high pressure vessels. One of the most widely applied materials in P110 that has enormous levels of toughness and yield strength.

Carbon Steel

Carbon steel is a strong and highly employed material in CNC machining. It is an alloy of carbon and iron. Carbon has a range of 0.05% to 2.1% by weight in this material. Low-cost, hard, remarkably strong and can be machined and cut with relative ease, with higher levels suitable for chromising. Main categories in three forms are:

• Low carbon steel: In low carbo steel the carbon content is from 0.05% to 0.25%. It is ductile and malleable and suitable for machining. It is relatively low in cost. One well-used category is AISI 1018, which is weldable and machinable.
• Medium carbon steel: In moderate carbon steel the carbon content will be from 0.25% to 0.60%. It is stronger than that of low steel and have better ductility. In this category, a highly employed material is AISI 1045uminium cylinder head. The tool can.
• High carbon steel: In high carbon steel, the carbon content will be from 0.60% to 2.1%. It is more strong and extremely tough but has little malleability. A suitable category in this is,

AISI 1095, a popular high carbon steel can be machined at cutting speeds from 45 to 70 ft/minute and feeds of 0.0015 to 0.003 inches per pass.

Machining Process

The approach is employed to acquire the desired parts with extreme precision.

• Workpiece material selection
• Preparation of material
• Setting up workplace of machines
• Selection of tools
• Feed and speed calculations
• Final approach.

Real-world applications

• Engine components: The items are generally used in engine construction, including the chassis and panels of the car body. It is often used in steering handles and wing exteriors of the vehicles due to its strength.
• Crankshafts and gears: Carbon steel is used for shanks, axles, chains, and crankshafts. The crankshafts outperform other steel as it is not broken by any rotational impacts and coordinates the motor parts.
• Blades and springs: It is used for manufacturing blades and springs as they retain edges and bands or ornaments for tougher applications than normal use.
• Wear plates: The feature is generally placed in a programme where they are either parallel to or hardened by the drilling edge. A sturdy steel backing plate has been installed and the welding members are only visible on one face.

Aluminum

CNC machining aluminum, one of the most common materials in the production operations, and such actions are rather wide-spread in many industrial sectors, including agriculture, the automotive industry, electronics, aerospace, and so on. This material is chosen for many its properties such as excellent machinability, the strength-to-weight ratio, and the ability to resist corrosion. Aluminum is a material that is widely used for various parts, and components and it is of common participation in the construction activities as it is utilized to produce window frames of the buildings and for such tasks as the production of fasades. In the electronics industry, this material is chosen to manufacture heat sinks automotive framing, and suspension similar parts. This paper aims to discuss the properties of cnc machining aluminum, the processes and tools required for CNC machining aluminum, and the real-world application of this CNC machining variant.

Aluminum Other Properties

The following are the other properties that have contributed to the popularity of this material in our study:

• Lightweight. This material is about one-third heavier than steel and its density is of 2.7 g/cm
• High strength-to-weight ratio. Aluminum provides much strength for many applications of the part without adding correspondingly much to size and weight.
• Corrosion resistance. This material forms a protective natural oxide layer of corrosion resistance and such effects make it possible to put this material to outdoor and marine applications.

Aluminum’s Machinability

CNC machining aluminum is performed due to its excellent machinability. Moreover, similar processes are cheaper as opposed to may metal-specific processes. There exist several steps that should be obeyed to achieve high precision and throughput frenwcy. First, the aluminum material must be selected, namely its alloy. Fixtures should be set, tools should be chosen, followed by the exact machining process. The aluminum cutting speed and feed rage must be set and they are the main factors defining the final throughput frequency and precision level of the process. Throughput cooling and lubrication should also be applied, followed by finishing operations.

The Real-World Applications

In the aerospace industry, aluminum is of common utilization for aircraft components such as fuselage frames, wing panels, and landing gear and 7075 aluminum. The automotive industry applied CNC machining aluminum for the coating of specific parts, often to cut their final weight and increase fuel economy 6061 aluminum. In the electronics industry, the material of aluminum is used for the production of the heat sinks for the electronic enclosures 1050 aluminum. Similar material is used for the construction of buildings such as buildng facades, window frames, and structrures. 6063 aluminum is used for architectural applications due to its excellent finishing qualities.

Brass

Brass is a highly durable and versatile material that is used in CNC machining. It is an alloy of zinc and copper and boasts excellent machinability, resistance to corrosion, and aesthetic characteristics. The material is used in various indoor and outdoor applications in plumbing, electrical, and decorative industries. From a manufacturing perspective, brass offers a range of benefits relevant to machining stainless steel substances with CNC techniques.

CNC Machining of brass

The process of machining brass involves a number of steps that must be implemented to ensure the production of high-quality and precise parts.

1. Material selection : Determined by the application, most common brass alloys are C36000 , often referred to as Free Machining brass, and C26000

2. Fixtures setup: The main fixture is positioned, ensuring that the workpiece is firmly attached to eliminate any movement throughout the entire machining process.

3. Tools selection : A machinist uses high-speed steel and carbide tools and may decide to coat them with TiN to enhance the tools’ lifespan and reduce friction.

4. The machining process : Brass materials can be machined at high speed because of their excellent machinability. Per Goulds et al. the Free Machining C36000 requires a cutting speed of 150-300 SFM and a feed rate of 0.002-0.005 IPT. The tools are cooled with oil or water-soluble coolant. However, it should be noted that brass does not get as hot as other metals, and the cooling process mainly aims at enhancing the surface finish.

5. Finishing operations : include the deburring of the edges and polishing of the equipment by cutting.
6. Post-machining operations : The materials are surface treated to prevent corrosion. The treatment might include applying lacquer. Such machined parts as plumbing fitting may be sent for assembly.

Real-world applications

• Plumbing. In the plumbing industry, brass fittings, pipes, and valves are commonly used. The material is known for its resistance to corrosion, high temperature and pressure.
• Electrical. In electrical applications, brass is the material of choice for connectors, switches, and terminals.
• Musical instruments. In the industry of musical instruments, brass is used for the manufacturing of wind instruments as it possesses appropriate acoustic characteristics. Brass is also valued for its aesthetic qualities.
• Decorative items. Furniture, lights, vases, and jewelry made of brass are appreciated by the customers due to the yellowish color of the material.