Common problems in CNC machining of aerospace components

 Before processing, it is necessary to find suitable materials. Special plastics and superalloys are difficult to procure, with high transportation costs and time-consuming processes. Including nickel alloy, titanium, The latter is a type of plastic used in aerospace applications. The aviation industry components have always required these materials, which is a long-term challenge.

 The production of airplanes is completely different from other products. Many aerospace components are not mass-produced. An airplane requires many different parts, each of which may only require a few hundred or fewer. This is multi variety, small batch production. Unfortunately, the production of multiple varieties and small batches contradicts the manufacturer's original intention. Manufacturers need to spend time and effort reviewing and setting up manufacturing processes for each component, so some manufacturers simply won't accept projects that require them to spend time developing complex geometric processes to manufacture several components. Sometimes it is possible to order more quantities, but if post-processing of the parts is possible, it may allow you to increase the order quantity and store excess parts for future use. But it is only applicable to persistent designs that can be used for future aircraft models, and requires additional space for storage.

The following are different problems that are often faced when manufacturing aviation components, as well as solutions.

Part size: An aircraft is composed of millions of parts. There are many small parts, but also some large components. We must find a supplier with a large CNC machine to handle parts of this size. Otherwise, you will have to redesign the parts. This may require breaking down larger components into smaller parts. However, this may increase the overall weight as assembling multiple smaller parts requires additional fasteners. On the other hand, the manufacturing method can also be changed. Casting can produce large parts in one go, but it may still require CNC machining for post-processing. The casting time is longer because molds must be designed and manufactured before producing any parts. Casting is more cost-effective than CNC machining for small batch parts.

Processing large thin-walled components:Some components have large internal cavities. It requires a lot of time, generates a large amount of waste, and also leads to residual stress in the parts. Residual stress can cause warping and deformation. In this situation, there are several options. If the required quantity of parts is small, one part can be processed and tested. If it meets the specifications, it can continue to be tested for each part.

Sometimes, such components can be cast, which is more suitable for producing large components with thinner walls, resulting in less material waste and less warping. In order to achieve precision machining and meet tolerance requirements, CNC machining may still be necessary. At the same time, special high-performance 5-axis CNC machine tools can be used, which have stronger power, speed, and control. By using lower force and speed, thin-walled parts can be processed without applying too much force to cause deformation. In addition, parts can be machined symmetrically using radial or axial cutting depths, which can reduce residual stress.

Appropriate material properties

It may be difficult to achieve the highly specific material properties required for aerospace. Metals generally require heat treatment to obtain the required hardness and strength. Pre processing heat treatment will greatly improve the hardness and strength of the material, and can maintain stricter tolerances. However, processing hard materials takes more time, wears out tools more, and incurs higher processing costs. If heat treatment is necessary, tools made of harder materials such as titanium instead of carbides can improve these issues.

At the same time, there are also some issues with heat treatment after processing, which may affect the size of the parts, reduce the accuracy of CNC technology, and cause the parts to exceed specifications. This situation can be improved by selecting the most efficient heat treatment. At the end of the heat treatment process, pressure quenching can be used instead of oil quenching. Oil quenching causes faster shrinkage of materials, resulting in larger dimensional changes. We also need to accept the increased cost and delivery cycle of heat treatment. Quality is the key to CNC machining, and improving quality requires sacrificing speed and incurring costs. Another option is to perform a small amount of final processing after the hardening process. This way, you can perform most of the processing on the pre hardened material and complete the hardening process to achieve the required tolerances for the final part.

 1. The Importance of CNC Rapid Prototype Manufacturing: CNC machines rely on 3D CAD models and computer instructions to create parts, allowing aerospace engineers to quickly create new prototype designs, test them, and edit them. CNC rapid prototyping manufacturing does not require investment tools, helping aerospace companies minimize costs to the greatest extent possible.

5-axis CNC machine tool assisted manufacturing of complex designs: aerospace component design is becoming increasingly complex. For example, the landing gear and fuselage of an aircraft are very large, and some small details require extremely strict tolerances. 5-axis CNC milling machines can achieve ranges that 3-axis or 4-axis machines cannot reach.

High quality materials will improve processing: these materials include stainless steel, carbon fiber composite materials, aluminum alloys, titanium alloys, and have excellent properties such as heat resistance and high strength to weight ratio, making them very suitable for aerospace applications.

Lightweight metals are crucial for performance: aluminum and titanium are the most commonly used metals in aircraft due to their high strength. Steel is stronger and cheaper than aluminum, and is similar in strength to titanium. Titanium is as strong as steel, but 45% lighter in weight, while aluminum is about 33% lighter. Lightweight metals help improve the fuel economy and overall efficiency of aircraft. The disadvantage is that they are generally difficult to manually process. Numerical control machinery is compatible with multiple materials and highly dependent on them during the manufacturing process.

The importance of quality control: Regular maintenance of machine tools can ensure optimal performance and extend their service life. Regular routine inspections and calibrations can help manufacturers maintain the accuracy and efficiency of CNC machine tools. To ensure that each component meets the required specifications, a strict inspection protocol can be implemented before the assembly phase to identify and correct errors. Use advanced technologies such as coordinate measuring machines (CMM) and laser scanning to ensure the accuracy of parts.

Trends shaping the future of aerospace CNC machining: Technology is constantly evolving and manufacturers must keep up to compete. Several important trends are likely to drive the future of CNC machining in the aerospace industry: 5-axis CNC can produce complex parts with unique shapes.