dear  Kant Hegele, 

you are searching for the young's modulus of Ti6Al4V for temperatures higher then the melting point of 1923K? young's modulus means modulus of elasticity. Already by passing the Region of 0.2% Elongation Limit we Need to consider plasticity and young's modulus is not sufficient anymore. At about 873°K the flow stress is down to 50-100 N/mm2 and for temp as high as 1173°K or more I saw values around Zero.

On the other Hand E Calvert1, J Pollard1, M Jackson1, B Wynne1 and R Thackray*1

(Determining a flow stress model for high temperature deformation of Ti-6Al-4V

developped flow stress models for up to 1373-1473°K showing flow stresses between 28 and 43 N/mm2 depending on the strain rate applied.

Hi Kant,

I have temperature dependent Young's modulus of Ti6Al4V higher than the melting point of; in my case, 1969.98K.

It is a calculated value from the standard chemical composition of Ti6Al4V.

If you are running a thermal-elastic-plastic FEM analysis, the accuracy of Young's modulus higher than the melting temperature is not critical in order to obtain sound stress analysis results as long as it reaches to near-zero value parabolically.

Also, in order to improve the convergence of the stress analysis, Young's modulus cannot be zero at any temperature.

I wonder what Mr. Young would say about this, but elastical properties with liquid Phase volumes of 25% and more? What is the physical Basis for stress Analysis in partially solidified liquid? Isn't it determined by liquid properties and behavior? Are you talking about pure bulk material properties or due you include Skin Formation? It might be necessary or helpful for calculating some Parameter in liquid-solid Phase Transfer, but how could you varrify such data? I see the values you are suggesting are extremely small. For numerical simulations the  transitions from solid to liquid can be extremely important to assure numerical  convergence. Depending on the model and it's size (idealized periodic boundaries a.s.o.) the material behavior of real materials with many defects can be quite different.

In many FE software which can handle local melting, the mechanical properties of the liquid or liquid-solid mixture is set to zero and only thermal computation is performed in the liquid. I think this is a reasonable assumption of SLM process.

Beside those, you should avoid to define a very low Young`s modulus at temperatures near melting point. This will introduce numerical errors and convergence issues. This is related with "Zero or near-zero stiffness". If a significantly low stiffness material is connected to a higher stiffness material, this will also induce convergence issues etc.

Even though you can measure some stiffness and strength at temperatures slightly higher than solidus, it is usually very low (See nil-strength test). As elastic property determination is already an issue at high temperatures, I wouldn`t dare to measure elastic modulus at temperatures higher than solidus as it will probably full of errors.

Thus, I think you don`t really need that property.

Dear Kant,

I guess your question is not relevant now, but by definition liquids typically have no Yonug's modulus but bulk mosulus and Poisson's ratio of 0.5.

If you have other information please let me know.

Regards,

Ori