As with all hard-to-machine materials, nickel-based alloys present some significant challenges that can impact productivity, so it’s important to know what you’re up against.
- Material Differences. There are a number of different nickel-based alloys available, each with its own unique characteristics. Some are predominantly nickel and these are the softest of the alloys. They tend to become very gummy when machined. Other alloys, such as nickel-copper and nickel-iron, have higher strengths and are typically cold-drawn because they cannot be hardened through heat-treating. There are also some alloys that include titanium or aluminum, adding another degree of cutting difficulty. So the first step is to identify the type of nickel-alloy you are machining so that you can select the appropriate cutting tools, CNC machine type and program scheme.
- Work Hardening. In general, nickel-based alloys tend to become work hardened during the cutting process. This means that the metal around the cutting tool can become much more difficult to machine as the process continues. So, again, selecting a cutting tool with the right geometry, hardness, coating and sharpness is critical.
- CNC Machine Suitability. Although using the right cutting tools for the specific alloy is vitally important, so is the capability of the CNC machine tool. It’s essential to use a machine with a rigid spindle and tool holder that will eliminate vibrations that contribute to out-of-tolerance parts. Maintaining constant spindle speed is vitally important because if the spindle starts to slow down the nickel-based alloys will work-harden and make the next pass more difficult. The machine’s control must also be capable of maintaining consistent acceleration and deceleration, and quickly process data so it can prevent dwelling or reduced spindle speeds. Finally, the CNC machine must have an adequate amount of consistent power to maintain optimum speeds and feed rates.
There’s much more to know about machining challenging materials and how to determine if you have the right tooling and machines to handle the job. For expert advice talk your Torrance, CA Haas Factory Outlet consultants. They have the experience to answer your questions, and they can introduce you to the new ST generation of Haas CNC lathes and turning centers that meet the demands of today’s machining challenges and those of the future. To learn more call (310) 381-0750, email: jphillips@haasfactoryoutlet.com, or visit www.haasfactoryoutlet.com.