Boride-Carbon Hybrid Technology for Ultra-Wear and Corrosive Conditions

This work discusses a study on a surface treatment for creating extremely durable low-friction, wear and corrosion-resistant surfaces for tribological components in harsh conditions. A duplex surface treatment was developed that combines the advantages of ultra-fast electrochemical boriding with those of hard tetrahedral amorphous carbon coatings. The friction and wear properties of the duplex treatment are compared to the boride-only treatment of AISI 1045 steel, while corrosion and contact fatigue behaviors of the duplex layer are compared to that of the single-layer carbon coating on low carbon steel. The duplex treatment yields wear rates as low as 6 x 10(-8) mm(3)center dot N-1 center dot m(-1) and a coefficient of friction of 0.14 when tested against a steel counter face. The contact fatigue impact tests reveal that the high hardness of 1200 HV0.05 of the borided layer in the duplex treatment leads to higher resistance against indentation but is accompanied by a higher incidence of crack initiation, being in good agreement with the finite-element modeling of nanoindentation results. The duplex coatings exhibit resistance to pinhole corrosion as evidenced by a 3 h exposure to 15% HCl at room temperature.

Automated summary

The study developed a duplex surface treatment combining electrochemical boriding and hard tetrahedral amorphous carbon coatings to create extremely durable low-friction, wear, and corrosion-resistant surfaces for tribological components in harsh conditions. The duplex treatment showed excellent friction, wear, and corrosion resistance properties, with wear rates as low as 6 x 10(-8) mm(3)center·N-1 center·m(-1) and resistance to pinhole corrosion after exposure to 15% HCl for 3 hours at room temperature.