STUDY BEHAVIOR AT DYNAMIC AND STATIC STRAIN OF SOME DOUBLE LAYER MATERIAL

Sintered parts are subjected to the contact pressure, very often. This leads to surface degradation and removal them from use. Therefore, the material surface properties improving are necessary, especially resistance to wear and corrosion. Elaboration of double- or multi-layer materials is an appropriate method for this purpose. The method consists in making parts of powder layers, with different properties, and sintered them to gather. Double-layer materials were made with the base of iron powder and the coating of other powders or powder mixtures to study the behaviour of materials at dynamic and static strain. The obtained materials were subjected to tensile, shear, hardness, and contact fatigue tests to establish if these layers change the basic material properties. The experimental results show that coating hardness is always higher than of the basic material. In the same time, these layers improve tensile strength also. It was highlighted the coating layer adhesion to base material under static and dynamic strain by shear and contact tests.