Effect of solute content on constitutional supercooling

[waqasmalik]

Hello all.

I have a question about the the relationship between the amount of solute content in the molten pool and the degree of constitutional suoercooling. Is there any way that we can say that solute content influences the type of microstructure we get in the fusion zone?

Thanx in advance

 

[Dhurjati Sen]

Refer Physical Metallurgy Principles by Reed-Hill or Intro to Physical Metallurgy by Avner

DHURJATI SEN
Kolkata, India

 

[waqasmalik]

Thank you for the recommendation Dhurjati Sen.

I just wanted to ask that how chemical composition influences microstructure. Lets say an Al-Cu system, given two alloys one containing 3 percent copper and other 4 percent copper. Which will have higher tensency for dendritic growth?

Thank you

 

[Dhurjati Sen]

You got it wrong. Constitutional supercooling is not dependent on the composition but the temperature gradient in the liquid ahead of the interface.

Depending on the rate of cooling, you can get more dendrite in the 3% and vice versa.

DHURJATI SEN
Kolkata, India

 

time, time, time

The factor that non-metallurgists appreciate least about metallurgy and welding processes.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[waqasmalik]

Thank you for your response.

Please find attached the snapshot from the Welding metallurgy book by Sindo Kou.

The slope of a tangent to the equilibrium liquidus line which partitions the planar solidification front from the columnar or dendritic growth region is being given in terms of freezing tempertaure range.

For a given actual tempertaure gradient ahead of the solid liquid interface, will not the change in composition alter the equilibrium freezing range?

Thank you

 

[waqasmalik]

Anyone??

 

[waqasmalik]

@Ironicmetallurgist??

 

Sorry, but I was actually really bad at solidification theory!
My comfort zone is in the solid state; specifically steel weldments between 800-500°C.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[Dhurjati Sen]

Do understand, if Constitutional Supercooling is taking place, then there is no equilibrium freezing. The equilibrium liquidus now follows the curve (shown dotted). This actual reduction of the liquidus is called CS.

DHURJATI SEN
Kolkata, India