"Mark Fields" wrote in message
...

"Stealth Pilot" wrote in message
...

absolutely not. aluminium has such a heat transfer that molten
aluminium coming into contact with aluminium pins would soon have them
molten and fluid.

Stealth Pilot

I disagree. Daily we cast aluminum against aluminum, without two parts
knitting together, sucessfully. Also we know how to cast aluminum inserts
into aluminum. The problem has to consider the relative mass of the
aluminum pins vs. the amount, shape and pouring temperature of the
aluminum that is cast around the aluminum pins.

However, I would allow it is a difficult situation but not necessarily
impossible.

I agree. After casting, the 6061 would require a solution anneal before it
could be re-hardened. Heating the casting to 950 degrees F will provide
the solution anneal. Then it's just a matter of soaking the castings for
the prescribed period of time at the proper temperature to achieve the
desired T condition. Aging can not be accomplished without going through
the solution anneal process.

As Ed alluded, 6061 can be cast, too, although it doesn't cast as well as
other alloys. Years ago I machined a large number of cast 6061 pieces,
parts for a defense contract.

Harold