[TheForge] spring temper for brass question

[James Binnion]

>Hardening and tempering apply to many metals.  For example, aluminum 
>can be work hardened, but can also be hardened by heating at an 
>elevated temperature, natural aging and artificial aging.   One of 
>the most common grades for structural work( and what I am building a 
>plane our of) is 6061 T6, with the T6 indicating that it is hardened 
>by soaking at at 900 degrees and then artificially aged by soaking 
>at 350 degrees as I recall.  Brass is work hardened, but can be 
>tempered by precise heat treatment as well is my understanding.    I 
>would suggest that the original poster look to one of the clock 
>making lists to get his question answered.  There are many brass 
>springs found in clocks and tempering them is a normal process.
>
>Charles

Hi Charles,

	The only brass (Copper Zinc alloys) that can be hardened by 
heat treating are the beta brasses which have 37% or more zinc like 
Muntz metal (Cu60 Zn40) the lower zinc brass like the C260 (Also 
known as cartridge brass) that he referred to are only hardened by 
working. Muntz metal is the only available commercial CuZn beta 
alloy. It has excellent hot working capabilities but tends to be 
brittle when cold worked. It is typically hot forged to shape then 
heat treated  by first solution treating (heat to about 800C then 
quench) then ageing (heat to 300-500C for 30 min) to harden the alloy

-- 
Jim Binnion

James Binnion Metal Arts
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