Investment casting - Knocking out ceramic at the closed impeller waterway sidelines

[K79]

Dear all,

Could any one share information about making easier of removing fused ceramics (vane area). May be by chemically solvent or any thing?


Thank you

Kusuma

 

[cloa]

What is the composition of the investment cast and what is the cast alloy?

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[arunmrao]

Have you discussed with your consumable supplier. I presume, you are using ceramic cores . I understand that there are water soluble binders,though, I am not an expert on this topic.

I'm just one step away from being rich, all I need now is money.
( read somewhere on the internet)

 

[EdStainless]

Depending on the alloy I have resorted to hot alkali.
Then we re-desinged the cores to allow them to fracture easier.

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[tbuelna]

What process are you currently using to remove the shell? The most common methods are shot blast and water jet. These processes are quick, cheap and non-toxic, but they can be too aggressive for some components. If your impeller casting has vanes with thin edges/sections shot blast or water jet may not be acceptable. There are also chemical processes, like molten salt bath, that are effective at removing most types of investment shell. But the exact process would depend on what material the casting is made from.

 

[K79]

Dear all,

The material of the object is 316L Stainless steel, we still use the manually chisels + hammer + pneumatic vibrating knockout machine+ gun blast (steel shot).

@EdStainless : Hot alkali, could you please write the formula (supplier if available)?
@arunmrao : ceramics core is an option, but we also redesign the mold.. so im looking for other methods if available


Thank you guys, I hope theres more.. Ill try the chemically method for 1st step.


Warm Regards,

Kusuma P

 

[arunmrao]

kusumafoundry,
Do not use such primitive methods as chisels, sharp instruments they will damage the internal veins, leading to rejection. Ceramic cores is the answer, sand cores will not be a good solution for such applications.

Try using some of the alkalis,if it works good.

I'm just one step away from being rich, all I need now is money.
( read somewhere on the internet)

 

[K79]

Dear, arunmrao

Yes it is primitive, time consuming and dangering the object. I would like to improve this.

Thank you so much

Kusuma

 

[K79]

Im starting to work in investment casting, and this is one of the major problem.

Regard