This article illustrates the capability to reduce part cutting time for infrared (IR) germanium lenses without losing its surface finish or form precision.
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Figure 1. Nanoform® X
Method and Method Details
To achieve machining the germanium at three times the basic part cutting times, the Nanoform® X with hydroround oil hydrostatic B axis and HS150 work holding spindle are used.
The method involves a limited sweep, large radius, negative rake diamond tool. The tool is set off the center of B utilizing virtual center technology (VCT). The spindle speed recommended is 5000rpm with a feed rate of 15mm/min and feed per revolution at 3µm/rev, the coolant used is odorless mineral spirits (OMS).
B Axis Specifications
The B axis specifications are listed below:
- Bearing type: oil hydrostatic
- Axial stiffness: 600N/µm (3,428,000lbs/in)
- Radial stiffness: 225N/µm (1,280,000lbs/in)
- Moment stiffness: 3.4N-n/µrad (30lbs-in/µrad)
Details of Components
The components are made from germanium and measure 100mm in diameter with a concave radius of 163mm.
Results
It is possible to increase the speed up to seven times of the general processing time but still achieve yield form and finish results that are below basic IR specifications. The form precision is 0.197µm PV while the surface finish is 0.4845nm Ra.
This information has been sourced, reviewed and adapted from materials provided by Precitech.
For more information on this source, please visit Precitech.