Selecting which types of materials you’d like to use for your next CNC machining project can be challenging. Softer metals, such as aluminum, copper, brass, and bronze, are easy to machine and perfect for various applications. However, most exotic materials, such as Inconel, Invar, Kovar, and Titanium, are not as easy to machine.
Machining exotic materials, often referred to as high-performance or advanced materials, presents a range of formidable challenges to manufacturers and engineers. These materials, which often possess exceptional properties like high strength, temperature resistance, or corrosion resistance, require specialized approaches due to their inherent toughness.
What are the 4 most unique properties of exotic materials that make them challenging to work with? Learn more about them below.
1.) They are hard and abrasive
Exotic materials are often hard and abrasive due to their specific compositions, crystal structures, and material properties that contribute to these characteristics. The hardness and abrasiveness of exotic materials provide them with desirable qualities such as superior wear resistance, durability, and the ability to withstand extreme conditions. This quality makes them extremely attractive for use in harsh environments, such as aerospace or high-tech industries, where they may come into contact with abrasive particles, high temperatures, and corrosive agents. Their hardness helps them endure these conditions without significant degradation. However, these qualities also lead to accelerated tool wear and reduced tool life when working with the materials.
2.) They retain strength at high temperatures
Exotic materials retain strength at high temperatures due to their unique atomic and microstructural characteristics. This property is critical in applications where materials are exposed to extreme heat, such as in aerospace, energy, and other high-tech industries.
One key factor is the arrangement of atoms within these materials. Exotic materials are often engineered with specific crystal structures that provide exceptional stability even at elevated temperatures. These structures can resist atomic diffusion, which is the process that causes conventional materials to weaken and lose strength as temperature increases.
Some exotic materials contain alloying elements or compounds that create strong chemical bonds within the material’s matrix. These bonds effectively counteract the tendency for atomic movement and structural degradation, preserving the material’s mechanical properties at high temperatures.
Also, exotic materials can exhibit properties like creep resistance, where they resist deformation and maintain their shape under prolonged exposure to high temperatures and mechanical stress. This resistance to creep is essential for applications involving prolonged use at elevated temperatures.
3.) They are resistant to fatigue
Exotic materials often resist fatigue due to their superior mechanical properties and specialized microstructures. Fatigue is when a material weakens and eventually fails under cyclic loading or stress, a common issue in various industries, including aerospace, automotive, and structural engineering. The resistance to fatigue in exotic materials can be attributed to several factors, including high inherent strength, superior thermal stability, they distribute stress evenly to help prevent microcracks, and more.
4.) They exhibit poor thermal conductivity
Exotic materials often exhibit poor thermal conductivity due to their unique atomic and microstructural characteristics. While poor thermal conductivity can present challenges in specific applications, it can also be advantageous in others. Exotic materials often have complex crystal structures with irregular arrangements of atoms. These structures can impede the efficient transfer of heat through the material, leading to poor thermal conductivity. The types of atomic bonds present in exotic materials can influence their thermal conductivity. Materials with strong covalent or ionic bonds tend to have lower thermal conductivity because these bonds restrict the movement of heat-carrying vibrations (phonons) between atoms.
Exotic materials often need to maintain their integrity at high temperatures, where thermal expansion and thermal stresses can be significant. A low thermal conductivity can help reduce the heat transfer rate and limit temperature gradients within the material. Poor thermal conductivity can also contribute to heat retention within a material, which might be desirable in certain applications like high-temperature sensors or materials used in thermoelectric devices.
Exotic materials with low thermal conductivity can be used in specialized applications requiring precise heat flow control. This includes applications like thermally insulating films, heat sinks, and components in electronic devices.
Their unique properties mean that they need to be handled by an experienced shop, like O&Y Precision
The unique properties of exotics make them challenging to work with. They necessitate developing and using advanced cutting tools, innovative cooling techniques, and precise process control strategies to effectively machine exotic materials while maintaining quality, accuracy, and efficiency. When selecting a shop to machine your next parts, be sure that they specialize in working with exotics to be sure they can effectively work with these materials and your project will be handled correctly, on time, and within budget.
How can O&Y Precision, Inc. help you?
Our team has experience with a wide range of materials, from mild and hardened steel to a variety of exotics and plastics. O&Y Precision, Inc. is a quality-driven manufacturing company focused on providing top-notch custom parts, on-time delivery, and building long-lasting relationships. Our word is our bond. Whether your project is a quickly needed, a small quantity prototype, or a full production run, we will make it happen – on time, guaranteed. Contact us today with any questions or to get started on your next project, and let our O&Y Precision Machine Shop expert team bring your vision to life!
