A356 vs. Japanese wonder metal 1

[the1real1Grinder]

Greetings!


Should I just be happy with locally available A356?


I have just joined the forum. I was greatly surprised to find that somebody has used my real name, Grinder, for his handle. I'd rather be handleless.


I got EDS chemical analyis of a 2000 Kawaski XZ12R motorcycle engine's liquid-cooled cylinder head. This head is very similar in design and application to one of my own design that I will be having cast.


The conclusion from a friend of mine about that analysis was "dirty scrap".
(Dave does great study of car engines and motorcycle engines.)
(Dave is no metallurgist, Dave is no foundry man!)


The EDS chemical analysis: (formatted for mono-spaced type)
silicon:::: 9.1%;
ferrum::::: 0.45%;
cuprum::::: 2.5%;
mangansese: 0.17%;
magnesium:: 0.42%;
chromium::: 0.06%;
nickel::::: 0.03%;
zinc::::::: 0.88%;
titanium::: 0.03%;
plumbum:::: 0.06%;
stanum::::: 0.03%;
berylium:::<0.01%;
vanadium:::<0.01%;
zirconium:: 0.01%;

That all totals to about 13.74% to about 13.76%, depending on those &quot;<0.01%&quot; values.

The EDS chemical analysis specified the aluminum content as 86.3%.


(Chromium? Nickel? Stainless aluminum?)


If I cast the liquid cooled cylinder head in A356, commonly used, for example, by Edelbrock, for their mass-produced high-perfomance and racing cylinder heads for common V-8 engines, am I getting a much better material? I know mostly what I have read in my &quot;Casting Kaiser Aluminum&quot; book, such as A356 being specified with a maximum for other metals of 0.05% each maximum, 0.15% total maximum, and 91.88% aluminum, minimum.


Goals for the alloy include decent enough castability and decent enough machinability that the project can be finished. This for for low volume, less than 50 parts, each of about 6&quot; X 8&quot; X 13&quot; after machining, maybe about 25# gross per pour.


This will be a much-cored and much-machined sand casting with no huge sections.


Goals for the casting include the usual for high-performance engine use, such as good enough hot strength, good enough non-porosity, good enough wear resistance.


Should I just be happy with locally available A356?


Thanks for any input,

Grinder Smith

 

[123Cat]

Grinder
Im just a boy but I think the right things are there
Cuprum is that copper ? at 2% sounds fairly good
And silicon
Thats an important one
Its not too dirty
I wonder what the big dogs will say about this one
Your choice, of material sounds good
123Cat

 

[123Cat]

Grinder old Bean
2024 which is a heat resist grade only has small amounts of alloys too
Soooooo
I would congratulate the Japs on using a matl that just does the job
Castability is your aim
I guess
Will be interested in other replies
Good Luck

 

[TVP]

The Japanese alloy for which you provided the chemical composition is not the same as 356/A356 due to the copper addition. 356 is nominally 7% Si and 0.3% Mg. Alloy 354 is a closer equivalent (nominally 9% Si, 1.8% Cu, & 0.5% Mg). The Cu will provide additional strength, especially at elevated temperature: at 150 C the yield strength of permanent mold cast 354-T6 is ~ 275 MPa. 356-T6 will only be ~ 120 MPa.

 

[the1real1Grinder]

123Cat,

&quot;Just a boy&quot;? Boy is wonderful! Whether by age or by experience, we all get more.

You typed very wisely about &quot;just does the job&quot;. Kawasaki consistently operates at a profit and the engine in question suffers few failures, even in racing.


TVP,

Your TipMaster status is born out in your statements! I re-checked my 1965 &quot;Casting Kaiser Aluminum&quot; book to find your statements in perfect accord.

What was new to me is the idea of copper adding hot strength. This is real metallurgy, something that I am learning without a university. I am a book reader. I see now that I need to find a source that describes the effects of various alloying ingredients in aluminum alloys for casting.


Thanks,

Grinder

 

[TVP]

Grinder,

Thanks for the nice workds. I aim to please.

The following link should provide some of the information that you need with respect to alloying elements in Al:

http://www.key-to-metals.com/Article55.htm

In general, the key-to-metals website has good information. For more in-depth data, check out some of the references from the ASM Bookstore:

Aluminum Casting Technology, 2nd Edition

http://www.asminternational.org/Tem...=Ecommerce/ProductDisplay.cfm&ProductID=11904

59 others

http://www.asminternational.org/Tem...opic&template=Ecommerce/Topic.cfm&TopicID=100

 

[123Cat]

Yes grinder you have to think about castability
Not so much hot strength as water cooled heads dont get too hot
The 2024 grade has good hot strength and is use in rods and heads in model engines
I wouldnt think it wouldnt cast though
Its the Manganese and silicon which do it for hot strength in 2024 I feel
And yes all that copper in 2011 give fairly high tensile too
And 2011 has higher tensile than say 6061 , but it loses out in hot strength to 2024 as it doesnt have that manganese or silicon
Yes its tough
Just have to be careful, in your selection
Your A356 sounds close to the mark
Good Luck
123Cat

 

[TVP]

2024 is a wrought alloy composition, and is totally unsuitable for casting into a complex shape like an engine cylinder head. 2011 is a free-machining grade that contains Pb & Bi. The relatively high strength comes from a combination of strain hardening due to cold drawing of wire/bars/rods and natural aging. Again, this alloy is totally unsuitable for casting.

Alloy 2024 is not really alloyed with Si-- the maximum limit is 0.5%, the same as Fe. The Mg & Cu are important as they promote GP zone formation, which results in precipitation hardening. Mn forms a dispersed precipitate that is effective in slowing recovery and in preventing grain growth.

 

[the1real1Grinder]

Ah, new information!

Article 55 at Key To Metals (mentioned by TVP) about aluminum's alloying elements told me a lot.

(Note that I never put down Kawasaki for their complicated alloy - whether it is dirty, whether it is planned, it does work well.)

&quot;
cuprum (copper).
Aluminum-cuprum alloys containing 2 to 10% Cu, generally with other additions, form important families of alloys. Both cast and wrought aluminum-cuprum alloys respond to solution heat treatment and subsequent aging with an increase in strength and hardness and a decreasein elongation. The strengthening is maximum between 4% and 6% Cu, depending upon the influence of other constituents present.
&quot;

Different than what I might have thought! By reading the entire article, looking at the effects of each element, and looking at the effects of various mentioned combinations - wow! - Kawasaki's alloy does seem better than I had thought.


&quot;
nickel.
The solid solubility of nickel in aluminum does not exceed 0.04%. Over this amount, it is present as an insoluble intermetallic, usually in combination with iron. Nickel (up to 2%) increases the strength of high-purity aluminum but reduces ductility. Binary aluminum-nickel alloys are no longer in use but nickel is added to aluminum-copper and to aluminum-silicon alloys to improve hardness and strength at elevated temperatures and to reduce the coefficient of expansion.
&quot;

&quot;
plumbum (lead).
Normally present only as a trace element in commercial-purity aluminum, plumbum is added at about the 0.5% level with the same amount as bismuth in some alloys (2011 and 6262) to improve machinability.
&quot;

The wrought alloys, oh, mentioned in the context of model engines. Ah, yes. No, this head will be a rather good-sized casting. Bar stock was never considered; I need cored passages.
True, the maximum temperature is hoped to be controlled by the cooling system; still, local hot spots will exist.
My whole goal in this project is to build up to a standard, not down to a price. I've got to feel good about this!
(Now I will search for a local foundry that pours small amounts of 354 and others.)


Thanks for the great insights, guys. The technical references are just what I needed!


Grinder