Latest Proofs of Validity of the Phenomenon of Phase Formation through a Stage of Liquid State in Metals Being Electrodeposited

The aim of the work was the experimental verification of the validity of the discovered phenomenon of phase formation through a stage of liquid state in metals being electrodeposited [1-3]. For that the features of formation of crystallographic texture in metals being electrodeposited under the influence of external (centrifugal) force in the directions opposite and along the texture axis were investigated.

General idea for the fulfillment of new experiments was based on the fact that the degree of perfection of crystallographic texture appearing in metals being solidified from liquid state at the action of the external force significantly depends on the direction of the force action. A change of the degree of perfection of texture in metals being electrodeposited with the change of the direction of minor force action (in comparison with the value of plastic deformation creating texture in solids) will be a proof of the validity of the discussed phenomenon.

Idea One and Its Realization. It is known that texture formation of metal during its solidification occurs by oriented crystallization in the direction perpendicular to the crystallization front. On the other hand, it is known that crystallographic texture of electrodeposited metal is the axial texture of growth with the axis perpendicular to the surface of a deposit. Assuming that crystallographic texture of metal being electrodeposited is formed as a result of oriented crystallization of continuously renewed metallic liquid, the action of centrifugal force directed perpendicular to the crystallization front and opposite to the texture axis will obstruct the formation of texture.

The investigations of features of oriented structure formation in metals being electrodeposited in the field of centrifugal force were performed on copper and nickel samples. As a result the effect of suppression of the process of texture formation in metals being electrodeposited up to the complete disordering of crystal lattices of grains under the influence of external force in the direction opposite to the texture axis was discovered.

Idea Two and Its Realization. It is known that texture formation during crystallization of metal occurs in the direction of the external force influencing the metal. At that the degree of perfection of texture of metal being solidified increases with the growth of values of the external force. Therefore, if metal being electrodeposited really passes through a stage of liquid state, then at the influence of centrifugal force on metallic liquid being solidified perpendicular to the crystallization front and along the texture axis the processes of formation and development of texture will intensify.

Features of texture formation in metals being electrodeposited in the field of centrifugal force acting along the texture axis were investigated on copper and nickel samples. The effect of intensification of the texture formation process in metals being electrodeposited at the influence of external force directed along the texture axis was found.

The comparative analysis of the degree of texture perfection of electrodeposited metals obtained at different directions of the force action during their phase formation was performed. It was found that regardless of the direction of the force influence the most significant change of the degree of texture perfection in metals being electrodeposited occurs at relatively low overloads. It was discovered that the action of external force in the direction opposite to the texture axis results in the more significant influence on the texture formation process in metals being electrodeposited in comparison with the force action along the texture axis. The obtained results prove the validity of the phenomenon of phase formation through a stage of liquid state in metals being electrodeposited.

References

1. O. B. Girin, “Phase formation through a stage of liquid state in metallic materials being electrodeposited: recent experimental proofs,” Int. J. Mater. Sci., vol. 2 (4), pp. 108–118, 2012.

2. O. B. Girin, “Structure features of metals obtained by electrochemical deposition and by solidification from liquid state in saturated hydrogen environment,” Chem. Mater. Eng., vol. 2 (5), pp. 119–126, 2014. doi: 10.13189/cme.2014.020503

3. O. B. Girin, “Crystallographic texture formation in metals being electrodeposited at the external force influence,” Amer. J. Mater. Sci., vol. 4 (3), pp. 150–158, 2014. doi: 10.5923/j.materials.20140403.06