Loading ...
Sorry, an error occurred while loading the content.

42656Re: [hobbicast] Re: Alloying

Expand Messages
  • StoneTool
    Mar 1, 2013
    • 0 Attachment
      Mikey
      You are right of course........... I assumed that members had tried
      this kind of thing. Putting a bit of copper into an aluminum melt
      1-10% is a far different thing from trying to dissolve 70% copper into a
      crucible of molten aluminum a bit at a time. It is after all the
      aluminum that is dissolving the copper into solution. There has to be
      a saturation point. Normally as I understand it you melt the
      primary metal and introduce the alloying components. Once copper
      exceeds 50% you are dealing with a copper alloy, not an aluminum alloy.


      Howard

      On 03/01/2013 08:53 AM, michael.a.porter@... wrote:
      > Howard,
      > That's an interesting supposition. "At some point" covers a lot of ground; I think you'd need to run an experiment to prove or disprove. An experiment, would probably be cheaper than asking a metallurgist.
      > Mikey
      >
      > ----- Original Message -----
      > From: StoneTool<owly@...>
      > To: hobbicast@yahoogroups.com
      > Sent: Fri, 01 Mar 2013 16:01:05 -0000 (UTC)
      > Subject: Re: [hobbicast] Re: Alloying
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      > Nelson:
      >
      >
      > Aluminum bronze is an alloy I am familiar with, and excellent
      >
      >
      > bearing material with good useful properties. My question here is, if
      >
      >
      > you keep feeding copper into molten aluminum without significantly
      >
      >
      > raising the melt temperature, at some point your alloy will become a
      >
      >
      > copper alloy rather than an aluminum alloy.... Presumably as you pass
      >
      >
      > 50%. I find it difficult to believe that the melt temp wouldn't have
      >
      >
      > to increase considerably as this point is approached and passed........
      >
      >
      >
      > Howard
      >
      >
      >
      > On 02/28/2013 09:10 PM, Nelson Collar wrote:
      >
      >
      >> No because the aluminum does not have the same properties that tin has. Aluminum is nothing but dirt-sand.
      >
      >> Nelson Collar
      >
      >
      >
      >> ________________________________
      >
      >> From: Robert Broughtonbroughton%40rocketmail.com" target=_blank>r.broughton@...>
      >
      >> To: "hobbicast@yahoogroups.comhobbicast@yahoogroups.com>
      >
      >> Sent: Thursday, February 28, 2013 8:43 PM
      >
      >> Subject: Re: [hobbicast] Re: Alloying
      >
      >
      >
      >>
      >
      >> There are different types of bronzes with differing levels of copper and some other metal or silicon content. However on all of them, the copper is the predominate (over 60 and usually over 90 percent) component in the alloy mix. If you are only adding 6 to 10% copper, it would be more of an aluminum alloy than a bronze. However, if you switched it around so you had 90% copper and 10 percent Al, then it would be an aluminum bronze.
      >
      >> Bob
      >
      >
      >> ________________________________
      >
      >> From: Nelson Collar nel2lar@...>
      >
      >> To: "hobbicast@yahoogroups.comhobbicast@yahoogroups.com>
      >
      >> Sent: Thursday, February 28, 2013 6:20 PM
      >
      >> Subject: Re: [hobbicast] Re: Alloying
      >
      >
      >
      >>
      >
      >> Howard
      >
      >> It may seem hard to believe but it is true. And no it does not become a bronze. It is a aluminum alloy with copper. After the aluminum is melted with no unmelted pieces in it, place the copper (I use from 6 to 10% copper) it will melt almost on contact. When it comes to remelting it, it does not act like the aluminum you melted in the first melt. The copper makes a very hard set and is a lot nicer to machine.
      >
      >> Nelson Collar
      >
      >
      >> ________________________________
      >
      >> From: StoneTool owly@...>
      >
      >> To: hobbicast@yahoogroups.com
      >
      >> Sent: Thursday, February 28, 2013 12:26 PM
      >
      >> Subject: Re: [hobbicast] Re: Alloying
      >
      >
      >>
      >
      >> Interesting...............
      >
      >> What I am reading is that feeding copper into ZA12, you can put a
      >
      >> lot of copper into the melt and achieve a bronze of sorts, but the melt
      >
      >> temp will not go up until you solidify and try to remelt. That somehow
      >
      >> the metal does not become a true "alloy" until it has cooled. That
      >
      >> seems a bit counter intuitive........
      >
      >
      >> Howard
      >
      >
      >> On 02/27/2013 05:08 PM, Wonk wrote:
      >
      >>> I've found when I alloy ZA-12 for example that I don't raise the temperature to melt the higher temp metals. I usually melt the zinc and hold it just below the temperature where it starts smoking off the add the aluminum and finally the copper. The higher temp metals must be fed slowly or you will freeze the lower temp metal, then yes you do have to raise the temp to bring it to liquid again. Actually this is true with the base metal also. I try to start with a puddle of the base metal and add slowly until the new ingot or charge is melted. The same goes for brass or bronze. I have a contact temperature probe that I dip into the liquid metal, which is fairly accurate, although I don't always use it. Much like grandma I add things by feel or look, which is often close enough for hobby work!
      >
      >
      >>> Wonk
      >
      >
      >>> --- In hobbicast@yahoogroups.com, "Michael Porter" wrote:
      >
      >>>> The lower temp metals dissolve the higher temp as indicated, and can be forced back out of solution--but at much higher temperatures. Which is why they come uout as gases; not liquids.
      >
      >
      >>>> --- In hobbicast@yahoogroups.com, StoneTool wrote:
      >
      >>>>> There have to be absorption limits related to temp. Tin for example has
      >
      >>>>> quite a low melt point as does zinc, yet the result of taking copper
      >
      >>>>> into solution is red brass (bronze) or yellow brass. Both have a
      >
      >>>>> considerably higher melt temp than the zinc or tin they are alloyed
      >
      >>>>> with. That says to me that as you melt more and more copper into
      >
      >>>>> these, the melt temp must be raised.............
      >
      >
      >>>>> Howard
      >
      >
      >
      >>> ------------------------------------
      >
      >
      >>> For discussion of Metal Casting and related issues
      >
      >>> this list does not accept attachments.
      >
      >
      >>> Files area and list services are at:
      >
      >>> http://groups.yahoo.com/group/hobbicast" target=_blank>http://groups.yahoo.com/group/hobbicast
      >
      >
      >>> For additional files and photos and off topic discussions
      >
      >>> check out these two affiliated sites:
      >
      >>> sandcrabs" target=_blank>http://groups.yahoo.com/group/sandcrabs
      >
      >>> http://groups.yahoo.com/group/Hobbicast1
      >
      >
      >>> Please visit our sponsor: Budget Casting Supply
      >
      >>> budgetcastingsupply.com/" target=_blank>http://budgetcastingsupply.com/
      >
      >
      >>> List Owner:
      >
      >>> owly@...
      >
      >
      >>> Yahoo! Groups Links
      >
      >
      >
      >
      >
      >> [Non-text portions of this message have been removed]
      >
      >
      >> [Non-text portions of this message have been removed]
      >
      >
      >
      >
      >
      >> [Non-text portions of this message have been removed]
      >
      >
      >
      >
      >> ------------------------------------
      >
      >
      >> For discussion of Metal Casting and related issues
      >
      >> this list does not accept attachments.
      >
      >
      >> Files area and list services are at:
      >
      >> http://groups.yahoo.com/group/hobbicast
      >
      >
      >> For additional files and photos and off topic discussions
      >
      >> check out these two affiliated sites:
      >
      >> http://groups.yahoo.com/group/sandcrabs
      >
      >> http://groups.yahoo.com/group/Hobbicast1
      >
      >
      >> Please visit our sponsor: Budget Casting Supply
      >
      >> http://budgetcastingsupply.com/
      >
      >
      >> List Owner:
      >
      >> owly@...
      >
      >
      >> Yahoo! Groups Links
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      > [Non-text portions of this message have been removed]
      >
      >
      >
      > ------------------------------------
      >
      > For discussion of Metal Casting and related issues
      > this list does not accept attachments.
      >
      > Files area and list services are at:
      > http://groups.yahoo.com/group/hobbicast
      >
      > For additional files and photos and off topic discussions
      > check out these two affiliated sites:
      > http://groups.yahoo.com/group/sandcrabs
      > http://groups.yahoo.com/group/Hobbicast1
      >
      > Please visit our sponsor: Budget Casting Supply
      > http://budgetcastingsupply.com/
      >
      > List Owner:
      > owly@...
      >
      > Yahoo! Groups Links
      >
      >
      >
      >
    • Show all 23 messages in this topic