This project deals with a electrically aided sintering processes in which a block a material undergoes deformation under loads and gets heated up with the supply of electricity during this process. Sintering is the process of compacting and forming a solid mass of material by heat and/or pressure without melting it to the point of liquefaction. This project investigates the effects on how temperature changes occur w.r.t to the increasing density of the block. The densification parameters as well as the plasticity parameter are taken into consideration to inspect how it affects the stress and strains occurring on the block.

As sintering is a process of compacting and forming a solid under heat and/or pressure, we see the temperature of the solid keeps increasing with time in the temperature vs. time graph which can be attributed to the fact that heat is continuously being supplied in the form of electricity. Thermal stress and strain are caused by temperature changes. The thermal strain is directly proportional to the temperature change after every time step. Due to constant increase in temperature of the block, the thermal strain also shows a similar behavior with time.

 

Sintering process is used to control densification and grain size during compaction. As the powder material is constantly loaded, the volume decreases (seen in the deformations of the cube at different time steps) and density keeps increasing until it reaches to the value of green compact. The densification parameter lies between 0 and 1 because theoretically after reaching the density corresponding to the green compact, the material has zero porosity to undergo compaction anymore. But in reality, the fully pressed part still contains some porosity and the green density will be lower than the true density of the material.  Thus we force the densification parameter to be zero beyond the range.

 

As the block experiences small deformations, we calculate the Cauchy’s stress instead of Piola-Kirchhoff stress tensor. From the graph, we can infer that the block’s transformation with rest to the coordinate system keeps increasing with time, as the stress tensor keeps increasing exponentially.

 

As the block is undergoing compressive loads, the pressure is a negative value. The pressure increases with time because the block undergoes compaction. As Compaction leads to smaller volume, the stress increases exponentially. Since Cauchy stress is the sum of volumetric and deviatory stresses. The deviatory stress values are considerably smaller values as compared to the Cauchy stress.