How to Appropriate the Right Materials for CNC Machining?

一、Application Scenarios Determine Material Selection

The final application of a part is the most important basis for material selection. Structural parts for aerospace require both high strength and low weight, which is why titanium alloys or aluminum alloy 7075 are often used. For medical implants, materials with excellent biocompatibility are in the forefront, such as 316L stainless steel or PEEK plastics. Different application scenarios require different mechanical properties, corrosion resistance and fatigue resistance of the materials.

二、Impact of Operating Environments

Temperature, humidity, corrosive substances or vacuum conditions in the working environment have a direct impact on material stability. In shipbuilding technology, for example, metal milling services generally recommend corrosion-resistant materials such as Hastelloy or duplex stainless steel. In high temperature environments, nickel-based alloys such as Inconel 718 may be required.

三、Dimensional Stability Requirements

For high precision cnc milling, the coefficient of thermal expansion and the behavior of the materials in terms of residual stress release during machining are particularly important. Although aluminum alloys are easy to process, their relatively high coefficient of thermal expansion can lead to dimensional deviations if they are not sufficiently aged. Conversely, Invar alloys, which are characterized by an extremely low rate of thermal expansion, are often used in optical platforms or highly stable measuring instruments.

四、Conductivity and Electromagnetic Properties

In electronic and electrical devices, the electrical conductivity of a material is often a decisive factor. Materials with excellent conductivity, such as copper and aluminum, are often used for cooling bodies or connectors. Conversely, certain applications require insulating materials such as PTFE or ceramics. In such cases, CNC Milling services must strike a balance between the requirements for conductivity and structural integrity.

五、Machinability and Cost

The machinability of a material determines the tool wear rate, the cutting parameter settings and the surface quality. Materials such as brass, 6061-T6 aluminum alloy and low-carbon steel are considered “easily machinable” and suitable for high-speed milling. Conversely, materials such as titanium alloys and hardened steel require special tools and cooling strategies, which significantly complicates machining and increases costs. Therefore, prioritizing workable materials while meeting performance requirements improves the cost-effectiveness of production.

六、Appearance and Post-Processing

For consumer goods (e.g. smartphone cases, high-quality watch components), surface quality – including smoothness, color consistency and anoxal effects – is of the utmost importance. In addition to machinability, these materials must also be suitable for post-processing techniques such as polishing, sandblasting and galvanizing. Aluminum alloys 5052 and 6063, known for their excellent suitability for surface treatments, have become popular options for 5-Axis CNC Milling.

七、Material Costs

Material costs and market conditions are practical realities faced by mass production projects. Even if an alloy has exceptional properties, high prices or long delivery times can require design adjustments. Engineers must therefore find the optimal balance between performance, cost and delivery cycles.

Conclusion

Material selection spans the entire lifecycle of a product, from prototype manufacturing to final use, serving as the core factor determining part performance and machining efficiency. Only by comprehensively considering all key factors can materials be precisely selected, enabling scientifically sound and rational material selection decisions.