High speed ultraprecision machining of germanium
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2019-11-15 |
| Authors | Hossein Shahinian, Jayesh Navare, Charan Bodlapati, Dmytro Zaytsev, Di Kang |
| Institutions | LAM Foundation |
| Citations | 4 |
Abstract
Section titled āAbstractāMass production of Ge lenses is a very common operation in the infrared (IR) optics manufacturing industry. The process of choice for production of such optics is single point diamond turning (SPDT). Ge is a very suitable material for SPDT and this gives the ability to produce complex elements with excellent surface finishes (<5 nm RMS). In this paper the application of the Micro-LAM (referred to Ī¼-LAM hereafter) process in SPDT of single crystal Ge is reported. The main idea is to investigate the maximum in-feed rates for a spindle speed of 5000 RPM as function of the tool nose radius and rake angle. Typical industry practice is to machine Ge with a spindle speed of 5000 RPM to 12000 RPM, and finishing in-feed rates between 0.5 Ī¼m/rev and 1 Ī¼m/rev. It is shown that an increase in the tool nose radius leads to an increase in the maximum in-feed achievable without the appearance of brittle fracture zones on the surface. It is also shown that using larger negative rake angles can also enable higher tool in-feeds without trade-offās to the surface quality.