Study of wear resistance in dry and lubricated regime of molybdenum coating obtained by thermal spraying

الملخص EN

Surface treatments and metallic coatings offer multiple functional specifities to protect all types of metallic materials as well as composites, it is possible to renovate or modify physical characteristics through a multitude of techniques.

This activity increases durability, corrosion protection, electrical conductivity or sliding characteristics.

This is a necessary step in the production process of many metal workpieces.

This surface treatment is suitable for parts of all sizes (bolts, pylons, car doors, etc.).

Surface treatments can also protect workpieces against various perils and recover worn surface losses.

The general principle of thermal spraying is to melt feedstock materials and inject it under high pressure on the substrate surface.

This technique is commonly used in many industrial sectors.

The thermal spraying of feedstock materials, such as molybdenum, which is a transition metal, has a high elasticity modulus, a high melting point and better mechanical properties (the addition of a small amount of molybdenum promotes the hardening of the steel).

Molybdenum surface treatments thus provide a form of protection for parts against certain tribological and electrochemical risks.

Surface treatments with molybdenum coatings greatly improve the protection of mechanical pieces against the severity of surface degradation phenomena such as tribo-corrosion.

In the present work, the main goal is to study the dry and lubricated wear behavior of a molybdenum coating deposited by wire-arc spraying technique on a mild steel substrate.

The coatings were characterized the coatings was viewed by a scanning electron microscope (SEM), Vickers micro-hardness and wear resistance using a pin-disc tribometer (pin/graphite disc).

The result obtained showed that the applied load is a factor influencing the mass loss of molybdenum deposits, which are subjected to a sliding speed of 1m/s and have a slightly higher wear resistance than the ones of coatings subjected to a sliding speed of 0.5m/s.

This result is observed for the two regimes studied (dry and lubricated).

Under dry conditions, we also noted that the self-lubricating properties of molybdenum coatings did not significantly reduce mass loss.