Spring material. Corrosion resistant, Fatigue resistant 6

[Merlinz]

I need to find an ideal spring material.
Cost is not an issue, so it may be an exotic.
The material must not be poisonous, e.g. no Berylium Bronze. This material would ideally have a Finite fatigue limit (Endurance limit), or at least a high strength up to 10^7 cycles minimum. The product is Musical instrument free reeds. Fatigue makes them go flat. Many instruments have many of them. Harmonica players breath through them.

Any suggestions of materials, and where I might find S-N curves for them appreciated.

Dave Fowler B.E.(Mech)UNSW Australia

 

[CoryPad]

The ideal spring material has the highest ratio of fatigue strength squared divided by elastic modulus. Thus, titanium alloys, spring steels, and fiber-reinforced composites have the highest ratios. The next step is to look for suppliers of semi-materials (sheet, plate, rod, etc.) that meet your geometry requirements. Member TVP probably can supply good suppliers for you. Good luck.





Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[TVP]

I am not very familiar with the internals of musical instruments, but I am assuming that free reeds require "flat" springs rather than helical compression springs, etc. Please correct me if I am wrong. For flat springs that require high fatigue strength and good corrosion resistance, I would recommend investigating stainless steel alloys with the correct spring temper.

Somers Thin Strip, part of Olin Brass, is a supplier of cold-rolled stainless steel spring materials. Check out the properties for Spring and Special Spring temper material:

http://www.olinbrass.com/stainlessdag.html

Other producers of high quality, high strength stainless steel strip include Sandvik and Hitachi. You can obtain more information from their websites:

Sandvik

http://www.steel.sandvik.com/

click on Strip Steel

Hitachi

http://www.hitachimetals.com/products/specialtysteel/

 

[mcguire]

The information on Somers was good. They make super full hard 301 stainless with YIELD strength up to 300,000 PSI.

 

[JimMetalsCeramics]

It might be possible to make such a piece out of glass or ceramic. Some candidate ceramics are ZrO2, Diamond (ultimate choice) and silicon nitride. You would be surprised that some ceramics can be made with elastic bend capability. They also have superlative acoustic properties and fatigue limits.

I know the ceramic field very well, if you need more info. How many of these do you need?

 

[ozandincel]

Hi Merlinz,


We are using the material 51420 St. Steel and our application also requires fatigue and corrosion resistance. We are producing components for artificial lims.
Pls find a list of sp.material & astm list

Hope the info is satisfactory...

Ozan

Spring Material ASTM Reference
Music Wire ASTM A228 (0.80%-0.95% carbon)
Oil-Tempered MB Grade ASTM A229 (0.60%-0.70% carbon)
Oil-Tempered HB Grade SAE 1080 (0.75%-0.85% carbon)
Hard-Drawn MB Grade ASTM A227 (0.60%-0.70% carbon)
Cold-Rolled Spring Steel, Blue-Tempered or Annealed SAE 1074, 1064, 1070 (0.60%-0.80% carbon)
Cold-Rolled Spring Steel, Blue-Tempered Clock Steel SAE 1095 (0.90%-1.05% carbon)
Chromium Vanadium ASTM A231
Chromium Silicon ASTM A401
Stainless Type 302 ASTM A313 (18% chromium, 8% nickel)
Stainless Type 304 ASTM A313 (18% chromium, 8% nickel)
Stainless Type 316 ASTM A313 (18% chromium, 12% nickel, 2% molybdenum)
Stainless Type 17-7 ASTM A313 (17% chromium, 7% nickel)
Stainless Type 414 SAE 51414 (12% chromium, 2% nickel)
Stainless Type 420 SAE 51420 (13% chromium)
Stainless Type 431 SAE 51431 (13% chromium)
Spring Brass ASTM B134 (70% copper, 30% zinc)
Phosphor Bronze ASTM B159 (95% copper, 5% tin)
Beryllium Copper ASTM B197 (98% copper, 2% beryllium)

http://content.engineering.com/engi...241-34D7FEEA970E6B4591F25E6CBED16854-,00.html