Cryogenic Machining of Metals

Machining professionals are under enormous pressure to increase productivity, reduce costs and meet increasingly stringent environmental regulations. The challenge becomes more difficult working with hard-to-machine materials like hardened steels, wear resistant alloys, and titanium alloys.

If you’re turning hard-to-machine metals, the revolutionary new ICEFLY cryogen delivery system can help you meet these challenges. Consider the potential benefits of cryogenic machining with the ICEFLY cryogen delivery system:

  • Increase cutting speeds and material removal rate by as much as 200% and reduce overall cycle time.
  • Increase tool life up to 250% and reduce machine downtime for tool changeover.
  • Avoid use of coolants and associated environmental, healthcare and product liability risks.
  • Reduce capital expenditures, labor, tool replacement and inventory costs.
  • Enhance removal of chips from the cutting area and eliminate coolant residues on machines, parts and chips.
  • Improve reliability of cutting with ceramic inserts while maintaining desired dimensional tolerances.
  • Improve quality of produced parts by preventing mechanical and chemical oxidation of machined surface.

The ICEFLY cryogen delivery system can be retrofit to virtually any vertical or horizontal CNC machine!

Cryogenic nitrogen can be turned on and off just like coolants!

Check out our Tech Notes page for informative white papers on the cryogenic machining of metals.

Temperature Controlled Machining of Polymers

Rate of deformation and temperature management are fundamental considerations in the machining of thermoplastic polymers, especially materials used in the fabrication of medical devices and other components with demanding specifications. With respect to polymer machining, deformation is controlled by careful selection of “time-dependent” machining conditions including cutting speed, feed rate and other application-dependent parameters such as cutting edge radius, tool angles and tool surface tribological properties. The machinability of polymeric materials also depends on temperature-dependent material characteristics including glass transition temperature (Tg), melt temperature (Tm), and viscosity. The accepted notion is that the best machining performance and optimum surface finish for polymer machining occurs within a small temperature window called the “cold flow region” around this glass transition region (See insert). As polymers are cooled through and below their Tg, their stiffness increases dramatically, typically by several orders of magnitude. The cold flow region exhibits more elastic deformation characteristics, compared to higher temperature ranges, where the material stiffness is significantly lower and the material exhibits rubber-like behavior. Machining in the rubbery range is characterized by significant tearing and waviness in thermoplastic polymers. At a temperature range lower than the cold flow region, thermoplastics are characterized by transitional brittle/ductile behavior, material smearing and unacceptable surface finish (tough region) following machining. At lower temperatures, extremely brittle and glassy behavior is exhibited by thermoplastic polymers and machining is characterized by micro-chipping and possible fracturing of the part surface.

Rationale for Temperature-Controlled Cryo-Machining

(Tg below room temperature)

Rationale for temperature controlled cryo machining - Tg below room temperature

Rationale for temperature controlled cryo machining

(Tg above room temperature)

Rationale for temperature controlled cryo machining - Tg above room temperature

To date, despite the important role temperature plays in the machining of thermoplastic polymers, precise control of heat removal from the machining operation has not been possible since coolants traditionally used in machining metal parts are: (i) not suitable for medical polymers, and (ii) do not offer temperature control capability for optimized performance. Cryogenic liquids and gases have been applied to cool polymeric materials; however, previous academic and industrial attempts at cryogenic machining have been hampered by issues related to heat leaks, pulsed flow and brittle fracture due to overcooling.

The ICEFLY cryogen delivery system addresses these issues by:

  • Providing a residue-free coolant (temperature-controlled nitrogen gas).
  • Providing non-pulsing flow control of cryogenic gas or liquid nitrogen.
  • Offering various pre-set temperatures and hence, refrigeration for a given polymer and machining conditions to prevent overcooling/undercooling.
  • Allowing machining of various polymers with different Tg’s.

Visit our Tech Notes page for white papers on the temperature-controlled machining of polymers.

Food Chilling

Use of liquid nitrogen or a low-temperature gaseous nitrogen stream can very quickly reduce the temperature of food products. This allows for improved processing. It can also be used as a means of preservation.

The ICEFLY® cryogen delivery system is well-suited for:

  • Applications where directed, focused cooling is needed.
    • Can deliver >25,000 BTU/hr refrigeration.
  • Chilling surface of food to effect desired properties or prior to packaging.
  • Modifying texture of food prior to slicing/dicing type operations.
  • Product or food processing development setting or for “on-off” type cooling applications in production facilities.