Parameter Considerations When Manufacturing High-Temp Alloys
At Specialized Turning, we are well-versed in machining high-temp alloys, electrical and controlled expansion materials. These alloys are preferred in many industries including aerospace, medical, electrics, sensing, and other industries where products require durable, heat-resistant components. They show high strength and stability at extreme temperatures, as well as exceptional environmental and creep resistance.
Experience to Optimize Production of Tough Materials
Specialized Turning has the experience and know-how to handle these tough materials while maximizing machining efficiency and offering the customer the most value. A few factors that contribute to the high cost of these alloys is the high amount of energy required to remove the metal. Once on the manufacturing floor, not only is the machining expensive, but the tooling, tool changes, and frequent inspection requirements add to the cost. When machining high-temp alloys, we must consider some tough parameters on the machining process to insure we produce the best results. They include:
- Metal removal rates – how fast the material can be removed while maintaining tolerances
- Surface finish quality – the rigidity of the tool is important to avoid surface imperfections, such as chatter or galling
- Dimensional accuracy – the combination of speeds and feeds to maintain a sharp tool to provide for a reliable and repeatable process
- Tool life – choosing the right geometry and surface coating for the tool, many manufacturers make material-specific cutting tools
- Inspection frequency – how often should the part’s critical features be inspected, especially on materials that tend to relieve stress in the machining operation
- Yield losses – monitoring how often a part is scrapped due to tool breakage or a critical specification being machined outside the tolerance limits
Machinability of High-Temperature Alloys
While finished precision high-temperature alloy components may have very technical features requiring high precision, some of the properties of high-temp alloys that impact its performance while being machined give credence to its classification as being tough to work with. Factors that influence high-temp alloy machining include:
- Poor conductivity of heat, effectively concentrating heat generated by the machining process to be conducted by the cutting tool
- Chemical reactivity which causes galling, welding, and smearing, which compromise the performance of the cutting tool
- Low modulus of elasticity requiring heavy cuts, sharp cutting tools, and general rigidity in tool holding, work holding, and the machine tool
- Fatigue properties, which will chip and or crack the cutting tool
- Work hardening characteristics where the machining process puts heat into the part, mostly from welded material on the tool
Sometimes all the planning and care will result in yield losses. Not only is the material lost but the tooling, tool changes, labor, and other overhead is lost with it. It all comes down to the design of the parts and how easy or hard it is to machine. When designing a part, engineers should be mindful of the challenges that manufacturing engineers and machinists face. Unnecessary tolerances and details such a small fillet or corner radii will definitely add cost to the part.
The team at Specialized Turning offers its expertise at machining difficult to machine materials such as titanium, Inconel, Hastelloy, invar, Kovar, and other specialty alloys. Our machine shop focuses on low-volume, high-precision, difficult-to-machine (DTM) materials for highly engineered applications. Contact us now to see how we can apply our expertise to your toughest and most challenging parts. Registered to the AS9100 quality management, system we serve customers in the aerospace, defense, medical device, high technology, and other discriminating industries.