In infrared optics manufacturing, everything starts with the blank. For materials like germanium, which are brittle and sensitive to stress, how you cut that blank makes a big difference later on. Poor surface finish or internal stress from the first cut can lead to cracks, polishing difficulty, or even rejection in final inspection.
That’s why more manufacturers are switching to diamond wire saws when slicing Ge blanks. With the right setup, this method delivers clean surfaces, low kerf loss, and—most importantly—minimal stress inside the material.
Why Germanium Blanks Require Gentle Processing
Germanium isn’t a hard material by definition, but its low fracture toughness means it doesn’t tolerate force well. Traditional blades or ID saws often introduce too much vibration or thermal load.
Common problems with conventional cutting include:
- Subsurface cracks that show up during polishing
- Uneven stress distribution across the blank
- High material loss due to wide cutting paths
These issues don’t just increase waste—they compromise the precision required for high-performance IR lenses.
Diamond Wire Saw: The Low-Stress Cutting Solution
A diamond wire saw slices material using an endless loop of fine diamond-coated wire. When tuned for germanium, this approach offers several distinct advantages:
- Wire thickness as fine as 0.3 mm, producing kerf widths under 0.35 mm
- Cold cutting, meaning no thermal distortion
- Smooth slicing with minimal mechanical stress
- Highly controllable feed and speed for delicate parts
Even on thick blanks (10–100 mm), you can get a clean cut surface with minimal need for post-grinding.
Real-World Result
A customer in the IR lens industry adopted the SG20 to replace blade saws for their 25 mm Ge blanks. After switching:
- Edge chipping dropped by over 60%
- Surface quality improved, reducing polishing time by ~35%
- Yield per ingot increased, thanks to tighter kerf control
Recommended Settings for Cutting Ge Blanks
| Parameter | Suggested Value |
|---|---|
| Wire Diameter | 0.3 mm |
| Feed Speed | 5-10 mm/min |
| Wire Speed | 40 m/s |
| Coolant Type | Clean, filtered water |
| Typical Thickness | 2–30 mm+ |
Holding fixtures should provide uniform support without creating pressure points. Rubber-padded clamps or custom molds work well.
Which Machine to Use?
Depending on your batch size and blank dimension, here are some good fit
- SG20: Compact and precise, great for R&D or small-batch blank cutting
- SGI 20: Higher throughput, supports contour cut
All models offer adjustable wire speed, programmable slicing, and built-in coolant systems.
When it comes to IR optics, the blank is the foundation. Cutting it right means fewer problems down the line. Diamond wire saws offer a cleaner, gentler approach—especially important for brittle materials like germanium.
If you want better yield, lower stress, and cleaner surfaces from the very first cut, Vimfun’s equipment might be the tool you’re looking for.
Let’s talk about how we can support your Ge processing needs.