jimjenkins
286
What is the current status of mean failure time of silicon balance springs ?
Dear Watch Enthusiasts:
First, by best wishes to you all for the 2014 and beyond.
I have occasionally been following the increased uses of silicon as a balance spring (hair spring). The stated purpose for such use is to eliminate the magnetization problems that can occur with metal balance springs.
Although I have no doubt that silicon will not suffer from magnetization issues, I am not convinced of its long-term reliability. My concern stems from the fact that silicon is a non-metal crystal, and as such will have a good propensity to propagate small scale cracks with repeated oscillations inherent with the balance spring. Since it is very difficult to synthesize perfect crystals of silicon spring, some nano-sized cracks or surface imperfections can remain.
Does anyone have any information on or can shed some light on the mean time before failure (MTBF) of silicon balance springs in comparison to metal balance springs ?
There are lots of very old watches that are still working perfectly with their original metallic balance springs. I wonder, what the future holds for silicone main springs. My concern is that silicone main springs may have to be replaced periodically - thus putting some negative spin on silicone's role in the watch industry.
Thank you all for your thoughts.
Cheers Jim
NB: I recognize that this would be a good question in a Material Science forum. However, I hope that there are some watch enthusiasts who are chemists, materials scientists, or would know such experts and post on this forum their thinking.
*** Mod - Pictured added for illustration purpose ***
What is the current status of mean failure time of silicon balance springs ?
Dear Watch Enthusiasts: First, by best wishes to you all for the 2014 and beyond. I have occasionally been following the increased uses of silicon as a balance spring (hair spring). The stated purpose for such use is to eliminate the magnetization problem...
That's a great question ...
I consider horology as a class of "slow science", since it must deal with items that we expect should last for a time span that is greater than our existence. New materials, like the silicon balance spring IMHO will be validated after we ... depart. Same ...
Excellent question...
Excellent question. I have heard that the silicon springs are more stable than steel. They return to form in cases where steel are deformed. There is certainly a limit at which they break and as you say the purity of the crystals will play a big part in t...
Some thoughts
Personally, I am less concerned about fracture mechanic induced failures from fatigue than I am from watchmaker induced component damage. At 4 Hz and beyond, > million cycles is achieved in days (a 4hz watch sees 245 million beats per year). Fatigue ba...
Very good point...
So another question to ask will be how does a silicone mainspring will respond to technicians nicks and bruises compared to metallic ones. My initial concerns were based on the manufacturing process, which is imperfect. However, your point is extremely im...
I'm a bit confused as to why liquidmetal
hasn't been used or at least considered. It's much more resistant and in theory should not be prone to the cracking you described.
A couple things to note
"Since it is very difficult to synthesize perfect crystals of silicon spring, some nano-sized cracks or surface imperfections can remain" Silicon can very easily be made with very high purity, beyond 99%. All of the semiconductors in your computer and pho...
Well, I dont think 99% is good enough for wacthes running +20K bpm.
Thank you for the reply. I appreciate the time you took to respond. As another, but occasional, nanolab user, I respectfully disagree with your assessment. Being able to synthesize 99% purity Si (or even 100% Si) does not guarantee a crystal defect free h...