Right now I am avoiding the intense rain here and am researching engine
stuff indoors.
I can easily mill the hole when I get ready, I have a couple expendable
housings that will work if the sweat is successful. IMS is down the
street if I need materials and I have a lot of that already. It's a
month or so down the road before I get into this particular project.

On a different note, I am learning how to do aluminum castings. I am
looking for the best casting material for center and end housings,
possibly one to the ceramic metal matrix hyper alloys and beralcast 363
for rotor material. It appears to be the only beryllium alloy on the
market and can be investment cast to near net. Do you have any knowledge
on this stuff? I've been reading about it for about a day, and looking
for a supplier.

Ed Carver

I have heard of aluminum/beryllium alloys .70% the density of aluminum.
Makes great rotors. What is the density of beralcast 363?

Paul Lamar



The spec related text is from the below link:

http://www.mdatechnology.net/techprofile.aspx?id=403

--

GENERAL BERALCAST�® ADVANTAGES

Advantages over Aluminum

* About 22 percent lower density with essentially equivalent
strength to A356 aluminum

* About 3 times stiffer (modulus of elasticity in tension)

* 2 to 4 times more dimensional stable than aluminum
to 10 times better in damping coefficient for stability and jitter
reduction depending upon the driving resonant frequencies.

* About 30 percent lower in coefficient of thermal expansion (CTE) for
matching of mating parts.

Advantages over Beryllium

*About 3 times greater ductility than hot pressed beryllium with
greater damage tolerance

*Castable for complex and precise net shape configurations

*Weldable for defect repair
*Reduced scrap generation, machining and environmental process
concerns. Does not require post-machined chemical milling

*About 1/4 the raw material input cost [of what?]


Sounds like the solution to the need for a better/lighter A356 alum.
Tomorrow I might be able to get a cost and availability on this stuff.

Ed Carver


Sounds like aluminum/beryllium alloy to me. What is the cost?

Paul Lamar


Just a thought.  I've spent 30 years as an RCP and the worst set of
non-smoking lungs I've ever seen came from an aerospace worker who was
working with beryllium in the 1950's, inhaled the dust and ended up with
a type of degenerative lung disease which eventually killed him.  The
toxicity  of this stuff is one of the reasons that it didn't become the
wonder metal we were all expecting.  If you're doing any  kind of
machining on this stuff you need the right equipment and safety
procedures.  In the 80's we had a patient that worked for Aerojet,
female, about  28 years old who came down with what seemed to be a
mysterious lung condition.  It took us over a year to get the powers
that be to tell us what kind of materials she was exposed to, and it
turned out she was in charge of manufacturing solar panels for spy
satellites.  All sorts of interesting metallic salts go into the alloys
on those things and she ended up with 70 year old  lungs.  A lot of us
used to haunt the disposal yards at the aerospace companies here in S.
California.  Good stuff and cheap, but some of it was dangerous if you
didn't know what you were doing.  Finished parts were usually ok.

George W

There are precautions that can be taken.
NC machine tools were unknown in those days.

Paul Lamar



P,

   Located on the Web.  Machining can be safely accomplished with
precautions...

 Breathing very fine particles may cause serious lung condition
 in a small percentage of individuals.  Risk from processes
 generating fine particulate can be minimized with simple,
 proven, and readily available engineering controls such as
 ventilation.

 *To be hazardous, airborne particles must be less than about
 0.00005 inch to 10 microns in diameter. * Particles in this size
 range are not visible to the aided eye; thus *the large, readily
 visible particles of most machining operations are not are not
 an inhalation hazard*.  Large particles do not remain airborne;
 and if they are inhaled, they are removed before they enter the
 small branches of the lungs.

 *As-cast or heat treated parts, with surface scale, should be
 machined with ventilation to prevent the scale from spalling and
 becoming airborne.*  Common housekeeping practices, such as wet
 vacuuming instead of blowing dust from equipment or floors, and
 keeping work areas dust free, are very effective in providing a
 clean, safe workplace.

 Beryllium copper is a ductile metal that machines easily,
 producing generally large chips and turnings.  *Machining
 operations such as drilling, boring, milling, turning, tapping,
 reaming, and non-abrasive sawing, that typically generate large
 chips, pose no significant exposure risk.*  These are machining
 operations where the liquid lubricant/coolant and the relatively
 slow tool speed prevent chips from becoming an airborne hazard.
 *Machining lubricant should be filtered, settled, or
 centrifuged, or changed regularly to prevent accumulation of any
 fine particles.*  The recycling of unfiltered lubricant/coolant
 can increase the beryllium exposure potential during machining.


Jack Beale








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