Combined with the vacuum coating working condition of your light guide fixture tray, the advantages of 6061 are targeted to solve production pain points, compared with 5052, 7075, cast aluminum and steel:
1. Ultra-low outgassing rate, critical for vacuum coating
6061 has stable silicon-magnesium alloy composition, few volatile impurities.
· In high-vacuum coating chambers, it barely releases gas particles, will not pollute optical film layers and cause fogging/spot defects on light guides.
· Cast aluminum, recycled aluminum and steel have high outgassing, easy to contaminate finished optical parts; 7075 contains high zinc content, prone to volatile residues under high temperature.
2. Excellent dimensional stability & heat resistance
Coating machines run under long-term 120~200℃ high temperature rotation:
· 6061-T6 precipitation hardening treatment provides low thermal deformation, concentricity and flatness will not fail after repeated heating & cooling cycles.
· Pure aluminum softens easily at high temperature; 7075 has larger thermal expansion coefficient, easy to warp after frequent high temperature.
3. Balanced rigidity & lightweight
· Rigidity: Enough hardness to maintain precise concentric ring grooves, will not deform during clamping, cleaning and repeated use.
· Light weight: Much lighter than stainless steel/iron, reduces spindle load of coating machine; high-speed rotation runs smoothly without vibration, ensures uniform coating thickness.
4. Superior CNC machinability for precision optical structures
The tray needs complex features: multi-layer concentric stepped grooves, dense small holes, threaded holes, square flanges and tiny R fillets:
· 6061 cuts smoothly, less tool wear, fine surface finish after turning/milling, easy to achieve flatness ≤0.01mm and concentricity ≤0.02mm tolerance.
· 7075 is sticky during cutting, easy to form burrs on tiny holes and ring edges, risks scratching light guide parts.
5. Corrosion resistance & reusable cleaning
The fixture plate needs regular chemical cleaning (alcohol, alkaline degreaser, ultrasonic bath) to remove coating residues:
· 6061 with passivation/brushed surface resists cleaning liquid corrosion, no rust, can be reused hundreds of times.
· Carbon steel will rust quickly without plating; unprocessed pure aluminum oxidizes heavily after multiple cleanings.
6. Cost balance for mass production
· Cheaper and easier to source than aviation-grade 7075 aluminum; higher performance than low-grade cast aluminum / 1060 pure aluminum.
· Perfect cost-performance for standard optical coating fixture mass orders.
7. Surface treatment compatibility
Straight line brushing + chemical passivation is the standard finish for this part: 6061 achieves uniform matte brushed texture to hide tool marks, avoids fingerprint sticking; we skip hard anodizing to prevent coating powder shedding, and 6061 performs stable under this treatment process.
If you would like to know more or have any related requirements, please feel free to contact us at any time.
