Technology Spotlight: Cryogenic Machining System

The demand for titanium is projected to grow as both civil and military aircraft production ramps up. Titanium, with its high-strength/lowweight properties, has become integral for the creation of components in this industry.

Titanium is used in numerous external framework and internal engine components. It can be found as part of landing gear, wings, propellers, as well as engine housings and fan blades that typically are exposed to high temperatures.

Modern commercial airplanes, such as the A380 and 787, are constructed from more titanium than older aircraft. However, it is the military aerospace industry that uses the most titanium.

This has led to the development of new technology specifically designed for machining titanium. One of the newest is cryogenic machining.

According to cryogenic machining expert 5ME, a twofold increase in semifinish cutting rates can be achieved when cutting titanium with cryogenic technology.

“Cryogenic machining reduces cycle times and energy consumption, while increasing throughput and tool life,” explained Pete Tecos, executive vice president of marketing and product strategy for 5ME. “It is a data-driven process because we can monitor temperature, flow rates, speeds/feeds, tool life, removal rates, and energy consumption to enable greener, cleaner, and more profitable production of hard-to-machine materials.”

Its sustainability advantages include elimination of mist collection, filtration, and waste coolant collection equipment; reduced energy costs; and a safer, healthier work environment, added Tecos.

“Cryogenic machining is particularly suited to the processing of tough materials like hardened/stainless/alloy steels, INCONEL®, and titanium, commonly used in aerospace part production,” said Tecos.

5ME’s patented cryogenic machining process enables higher cutting speeds for increased material removal and longer tool life by transmitting liquid nitrogen at -321 degrees F through the spindle/turret and tool body directly to the cutting edge.

It comprises six parts:

1. The source. Liquid nitrogen is stored in a central, self-pressurized storage location and then fed into the cryogenic machining system.
2. The feeder. The feed system consists of vacuum jacketed insulated lines from the machine source system to the spindle, ram, or turret system, depending on the machine. It also controls the flow of liquid nitrogen.
3. The subcooler. This component removes pressure-generated heat from the system and condenses dualphase material (liquid and gas) back to liquid.
4. The control. The system’s programmable NC regulates the flow rate through the feed system. It can allow for auto-override, emergency shutoff, and overflow of the system.
5. The spindle. The cryogenic tooling system can be retrofitted onto almost any OEM spindle, turret, or ram. A vacuum-insulated tube rotates within the spindle, allowing it to be used in high-torque and high-speed applications.
6. The tool. Cryogenic tooling is designed to interface with the cryogenic system and is required for proper functionality and safety.

Aerospace Applications

5ME has partnered with machine tool builder Okuma America to demonstrate the features of cryogenic machining by creating two cryo demonstration facilities—one at 5ME’s Technology Center in Warren, Mich., and the other at Okuma’s Aerospace Center of Excellence in Charlotte, N.C. These locations allow manufacturers to test different machining processes using 5ME’s cryogenic machining technology. Both facilities have Okuma machines equipped with cryogenic systems that use vacuum jacketed feed lines to deliver small flow rates of liquid nitrogen (LN2) through the tool directly to the cutting edge.

“This partnership gives us the opportunity to show the productivityboosting, energy-saving qualities of cryogenic machining, and assist aerospace manufacturers in their quest to meet tough part processing challenges,” said Wade Anderson, product specialist manager for Okuma America Corp.

www.5me.com

www.okuma.com