This process specification is for manufacture of cantilever spring blades for Advanced LIGO. It includes material requirements, limitations on shaping, detail on the nickel plating process and details of the age hardening fixture. These springs are for use in an Ultra-High Vacuum (UHV) system.
The following changes were added to version 9
1. Section 2.1 clarification that a Rockwell Type machine should be used for hardness measurements.
2. Section 2.2 changed the definition of thin springs to include plates up to 0.4 in (10 mm) thickness. (not shown in the version with highlighted changes)
3. Section 2.6 now includes details of a closed loop oven which can be used and information on how to position the blades during this bake step.
4. Section 2.7 includes information on the fixture material.
5. Section 2.7 also includes information on using a vacuum oven for the aging process.
6. Section 2.7 has information on where to measure hardness post aging.
7. Section 2.7.2 has clarification of the aging process for thick blades.
8. Section 3 has been updated to allow a closed loop oven to be used and gives information on how to load the blades.
9. Section 3 also has a new temperature for the alternative bake step.
10. Section 4 has been updated with new temperature information to be used in house by LIGO.
Calum Torrie and Doug Cook.