Producing complex aerospace parts such as vanes, blisks and impellers requires a particularly fast, very precise and extremely dynamic machining center. For manufacturing critical components used in engine and turbine construction, this means a 5-axis machining center. Machines for highly dynamic milling with five simultaneously controlled axes are essential for producing reliable aircraft engine components. A leading developer of CNC vertical milling and turning centers, the Chiron Group has brought a machining center to market precisely matched to the special requirements of the aviation sector: the FZ 16 S 5-axis with 5-axis tilt rotary table.
Optimal solutions for machining complex aerospace workpieces from exotic materials must provide superior rigidity for stable machining, high spindle speeds to make best use of cutting tools designed for shaping challenging metals, and rapid axis positioning to minimize cycle times. The result is production of high precision parts with high quality surface finishes in minimum time.
The mineral cast machine bed of the Chiron FZ 16, with rigid gantry design delivers a high degree of stiffness, and optimal damping characteristics. High-performance motors, two Y-axis drives, as well as short spindle startup and braking times are the foundation for the machine's extreme speed. A axes and C axes equipped with direct drives deliver even greater dynamics. These machine characteristics assure precise multiple-axis motion and smooth acceleration, which are fundamental requirements for high-level aerospace manufacturing.
“A key development for the Chiron machines, providing greater stability for the heavier cuts and the rapid axis positioning is the gantry-style construction rather than a C-frame,” said a company spokesman. “This construction will be seen in future Chiron Group machines. The base is a vibration-dampening, highly stable concrete material that is less sensitive to heat than cast iron or steel weldments. Even during heavy cuts, the machine runs nearly without vibration or noise.”
Combining high precision metal removal with high feed rates yields a machine that can hog material while delivering high quality surfaces. This capability is of great interest to producers of aerospace blisks and turbine blades, and complex parts from high alloy and exotic metals such as titanium, Inconel, and stainless steels. The ability to produce finished parts rapidly in a single setup saves cycle time and avoids the need for secondary operations.
“The exotic materials used for aerospace applications present challenging demands for high accuracy machining,” said Markus Löhe, aerospace sales engineer at Chiron. “The complex part geometries and the need for smooth surfaces require 5-axis simultaneous machining capability,” he said.
For example, a blisk consists of up to 120 individual blade components on a disk and has a diameter of around 800 millimeters. Workpieces of this kind can only be consistently produced on a fast, high accuracy machining center, such as the Chiron FZ 16 S 5-axis.
"Blisks are currently machined on Chiron machines from Inconel at one of our major customers in the sector," reports Löhe, “where the new FZ 16 S 5-axis machining center delivered excellent results from the first workpiece."
Related Glossary Terms
Cone-shaped pins that support a workpiece by one or two ends during machining. The centers fit into holes drilled in the workpiece ends. Centers that turn with the workpiece are called “live” centers; those that do not are called “dead” centers.
- computer numerical control ( CNC)
computer numerical control ( CNC)
Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.
Rate of change of position of the tool as a whole, relative to the workpiece while cutting.
- gang cutting ( milling)
gang cutting ( milling)
Machining with several cutters mounted on a single arbor, generally for simultaneous cutting.
- machining center
CNC machine tool capable of drilling, reaming, tapping, milling and boring. Normally comes with an automatic toolchanger. See automatic toolchanger.
Machining operation in which metal or other material is removed by applying power to a rotating cutter. In vertical milling, the cutting tool is mounted vertically on the spindle. In horizontal milling, the cutting tool is mounted horizontally, either directly on the spindle or on an arbor. Horizontal milling is further broken down into conventional milling, where the cutter rotates opposite the direction of feed, or “up” into the workpiece; and climb milling, where the cutter rotates in the direction of feed, or “down” into the workpiece. Milling operations include plane or surface milling, endmilling, facemilling, angle milling, form milling and profiling.
Using a shaper primarily to produce flat surfaces in horizontal, vertical or angular planes. It can also include the machining of curved surfaces, helixes, serrations and special work involving odd and irregular shapes. Often used for prototype or short-run manufacturing to eliminate the need for expensive special tooling or processes.
- stainless steels
Stainless steels possess high strength, heat resistance, excellent workability and erosion resistance. Four general classes have been developed to cover a range of mechanical and physical properties for particular applications. The four classes are: the austenitic types of the chromium-nickel-manganese 200 series and the chromium-nickel 300 series; the martensitic types of the chromium, hardenable 400 series; the chromium, nonhardenable 400-series ferritic types; and the precipitation-hardening type of chromium-nickel alloys with additional elements that are hardenable by solution treating and aging.
1. Ability of a material or part to resist elastic deflection. 2. The rate of stress with respect to strain; the greater the stress required to produce a given strain, the stiffer the material is said to be. See dynamic stiffness; static stiffness.
Workpiece is held in a chuck, mounted on a face plate or secured between centers and rotated while a cutting tool, normally a single-point tool, is fed into it along its periphery or across its end or face. Takes the form of straight turning (cutting along the periphery of the workpiece); taper turning (creating a taper); step turning (turning different-size diameters on the same work); chamfering (beveling an edge or shoulder); facing (cutting on an end); turning threads (usually external but can be internal); roughing (high-volume metal removal); and finishing (final light cuts). Performed on lathes, turning centers, chucking machines, automatic screw machines and similar machines.