It is not clear, what are you mixing ? for liquid melt like aluminum graphite and hot working steel with coating were generally used.

What is the operating temperature? What is the applied stresses on the component?

How can you describe the operating environment?

Hi veanuga

Usually for stirrer/mixing purposes, people use a martensitic stainless steel which is predominantly used to manufacture forks (which are used to cut meat) / eat food. This material has the capability to sustain high temperature. Even the blades of blender/mixer used to crush fruits/vegetables also use the same material to manufacture the blades. If in doubt, check in your mother's kitchen!!

Materials for stirrer : graphite , alumina , ceramic coated stainless steel.

I agree with the colleagues who asked about the operating conditions: temperature, speed of rotation (stress), the fluid being mixed. These factors need to be defined before a recommendation on the optimum material can be made. The size of the stirrer may also affect the material selection.

Hi veanuga,

        That`s depend on the material to be melt and stirrer,however Stainless steel(coated) and few cases we make with  graphite also.

Normally stainless steel is used for stirrers.

Please ....Can you explain  operating conditions for the mechanical  stirrer:

1-Raw materials in the mixer.

2- Temperature.

3-Speed.

4-Capacity.

5- Information about cost( high-or medium- or low).

6- product life.

in order to select the best engineering material.

Hi all for your information these are the detail explanation of the stirrer.

I would like to use the stirrer for the my project which is design a bio-oil test rig . This test rig consist of heating chamber, condenser and pump which is used to pump the water to the condenser. In the heating chamber stirrer is used to  stir the mixture of plant leave and water. Below are the detail of the stirrer and the motor used

1. Mixture that need to be stir is the mixture of mint leave(plant leave) and water where it will  be heat up the mixture using electrical water coil 

2, The temperature of the heating chamber will be maintain from 80 to 90 degree celsuis . 

3. The standard speed I would achieve is in the range of 90 to 100 rpm 

4. Using powder window motor of 12V DC motor

5. Since the budget for each group is limited so I am looking for low cost material

6. As long as it can withstand the pressure and temperature from the heating chamber 

martensitic stainless steel will do the job.

I think the Stainless steel 316 can be used to fabricate the mechanical stirrer.

Refer this link:https://books.google.co.in/books?id=ys4KJYKQ4S0C&pg=PA230&lpg=PA230&dq=suitable+material+to+be+used+in+fabricating+a+mechanical+stirrer&source=bl&ots=Mti6_zo4lb&sig=pqIjbFc2mHxP1FRIIdjQ85q7rJU&hl=en&sa=X&ved=0CCQQ6AEwAmoVChMI39GJqLr4yAIVyKGUCh1TtguH#v=onepage&q=suitable%20material%20to%20be%20used%20in%20fabricating%20a%20mechanical%20stirrer&f=false

Refer this link:https://books.google.co.in/books?id=YQT_R_3VEGoC&pg=PA79&lpg=PA79&dq=suitable+material+to+be+used+in+fabricating+a+mechanical+stirrer&source=bl&ots=A565dZf0M2&sig=DFvJls1WHNC2n-CUQH-XWwC2yY4&hl=en&sa=X&ved=0CCYQ6AEwA2oVChMI39GJqLr4yAIVyKGUCh1TtguH#v=onepage&q=suitable%20material%20to%20be%20used%20in%20fabricating%20a%20mechanical%20stirrer&f=false

Dear Veanuga Ganapathy,

You need to formulate your requirements more properly. It is not clear: a) temperature, b) media, c) velocity...

Graphite, Alumina , Coated steel.

It depends on the  melting material, temperature and other  parameters

Stainless steel is always the best...doesn't get rust....

Types Of Stirrers

Stainless Steel

Alnico

Neodymium Iron Boron

Samarium Cobalt

Dear Veanuga Ganapathy,

You need to mention temperature, type of mixture materials to be mixed and rotational speed

316L, simple the best.

Cress steels are ok. But stainless steels of 300 series are suitable,specially SS316L or may be SS304L (because you can find them every where).

Stainless steel is universal and good material, but is relatively soft and can be easly  scrached

That is dependent  on the stirred chemical solution.    If the stirred solution an aggressive solution, one would use a wide range of materials from a plastic Stirrer (Teflon) to a stainless steel, and so on.         

316L is common one.

But it also depends on your materials.

Ti containning alloys are suitable because of their excellent anti-corrosion capability.

Stainless steel is the common material used. However based on the application /medium you are going to use you can change the material.

For  such non-standard applications you better do some type of analysis to be more precise. Ashby  material selection text book, and CES Material selector software are the best tools that can help. You can also, read supplier catalogs will list a lot of informations in this regard 

Stainless steel is the common one

You have not stated the maximum temperature the medium of stirring would be subjected to.  Meanwhile, silicon-molybdenum alloy of cast iron should be able to perform well. Also, stainless steel comprising chromium and nickel would be a good material. In all,  choosing any material should involve performance requirements as well as cost consideration. 

stainless steel is the appropriate material for mechanical stirrer for anti corrossion

teflon and Titanium Based alloys are also used for mechanical stirrer in special environments

Stainless still is generally proper material for stirrers/mixing units (because of its stainless) but in some applications PTFE - teflon might be good to.

This depends on the material you want to stir and also on the operating temperature. Material for stirrer should not be the one that will react with the material you want to stir. The operating temperature should be very far below the recrystallization of the material for stirrer fabrication. All these are very important in selecting an appropriate material for your fabrication.

It depends upon the material you wants to stir.

 In case of aluminium stainless steel could be used. For the high temperature material graphite used. But in case of ferrous material certain c pick up observed. In that case ceramic stirrer iis being used. Now in case of aluminium melt stirring graphite is widely used. 

In any fabrication, purpose and cost must be considered to ensure economic conformity. 

Nevertheless, it is better to be precise about the reactants in your system and the possible highest temperature. With this, you will surely get a quick appropriate answer to your questions.

I would agree that what kind of the materials you wanna to stir, and also if we could know the operating temperature it must be easily to fine em.

In case of stir casting Al-SiCp ,, carbon reacts with Al firming harmful Aluminium Carbide at 700 deg. C.

As a stirring device Graphite cannot therefore be recommended. A suitable ceramic stirrer is recommended.

Dear Veanuga Ganapathy,

(1) Good Fabrication of Aluminum Matrix Composites by Stir Casting Technique and maintained Stirring Process Parameters Optimization could be optimal choice for mechanical stirrer.

(2) Metal matrix composite process the stir blade with shaft coupled with electric motor is used to stir the reinforcement with the molten metal’s. A major problem identified is agumentation, improper mixing of reinforcement, sedimentation on the blades and crucible surface should be wiped out.

(3) The EMS(electromagnetic stirring (EMS) system equipment is an effective process to improve a feed stock in the rheoforming process with improved mechanical properties. By controls the effects of several process and metallurgy parameters such as stirring current, stirring time, pouring temperature, forming pressure, tip velocity, fraction of primary phase, and its morphology and distribution can be highly effective. Mechanical stirrer become tough, hard and rotational achievement is also increased. Porosity reduction and corrosion possibility on blade is subsequently decreased.

Ashish