How can I determine the optimum cu-zn ratio for maximum hardness in brass?

[abolger89]

I need some help with information for making brass for a science project. I have access to a furnace and professional help. I need to know at what temperature i should heat the furnace to, how long i should wait before adding the zinc, what % zinc is lost due to vaporization, and how long i should keep the brass in the furnace after adding the zinc. The zinc content will be 35%-45%.

 

[pa5tabear]

Who is your professional help... can they answer these questions?

Temperature: I think this would be a tradeoff between maintaining a sufficient temperature but minimizing vaporization. You will have more vaporization at a higher temperature, but you will probably also see better mixing or the copper and zinc. Theoretically, the minimum temperature necessary to achieve a molten state should be no higher than the standard melting point of copper (freezing point depression caused by adding zinc).

I don't know how long to wait. I don't see any benefit in waiting past the "full melt" point.

The % lost due to vaporization will depend on time, pressure, temperature, composition, etc. You could assume that at the interface of your liquid metals and atmosphere, the concentration of zinc vapor is equal to its vapor pressure at the temperature. Then you need to know how much the atmosphere is moving to determine the mass transport of zinc vapor.

 

[abolger89]

A local institution is allowing me to to use their small furnace. They are only helping me actually carry out the procedure(for safety reasons).

Thanks this helped a lot.

 

[pa5tabear]

A local institution is allowing me to to use their small furnace. They are only helping me actually carry out the procedure(for safety reasons).

Thanks this helped a lot.

What's your background?

I'd be happy to try and explain things more.

Also please update with whatever happens! I'm curious how this sort of thing works in practice.

 

[abolger89]

I am a senior in high school. The project I'm working on is my extended essay for the IB program . I am currently taking my third year of chemistry and first year of physics. I'm trying to find the optimum ratio of cu-zn in alpha-beta brass for maximum hardness. I'm having a hard time researching, my questions seem to be too specific for the internet. Do you have any ideas on how to research this stuff? I appreciate your help.

 

[pa5tabear]

I am a senior in high school. The project I'm working on is my extended essay for the IB program . I am currently taking my third year of chemistry and first year of physics. I'm trying to find the optimum ratio of cu-zn in alpha-beta brass for maximum hardness. I'm having a hard time researching, my questions seem to be too specific for the internet. Do you have any ideas on how to research this stuff? I appreciate your help.

Maximum hardness isn't something I've learned about. That would be a materials science question, and it would have to do with the crystal structure (or lack of it) that forms when the metals are mixed. I don't know how composition would affect it.

You mentioned alpha-beta brass. Is that a specified alloy, or does it have a specified composition range? I'd guess that as you increase the amount of copper, the hardness of the brass increases (copper is harder than zinc).

For researching, I think forums are the best. Also independent searching, of course, but some stuff is just too confusing.

This link explains some, especially at the bottom:
http://courses.chem.psu.edu/chem112/materials/metals.html