SURFACE MODIFICATION OF CAMSHAFTS USING PLASMA MELTING METHOD IN HIGH-FREQUENCY MAGNETIC FIELD

Abstract

Continuous requirements for improving the quality of machines requires new investigation to constantly increase the production performance of parts. In this article, the surface of the cast iron EN-GJV-400 was remelted and modified via TIG (Tungsten-Inert-Gas) welding separately and simultaneously under high frequency magnetic field, as well as the microstructure and hardness of the specimens were compared.

It has been found that with the plasma treating of the surface under high frequency magnetic field the mechanical and tribological properties of the specimens have been improved. The hardness of the specimens from the cast iron EN-GJV-400 was increased after the surface remelting with high frequency and low energetic magnetic field. The microstructures of the modified surfaces through the conventional TIG and high frequency magnetic field were also not same. The reason was that the magnetic energy in the molten material in the latter method caused additional temperature in weld pool as well as the rotation of the it in the direction of the magnetic induction vector. The size of the grains has been increased via the additional heating effect and at the same time the dendrite branches have been cut to the smaller parts. The technology can be applied for the increasing the Hertzian contact pressure, tribological properties of surfaces and for the alloying and shaping processes considering the magnetic force on the molten material.