Improving the Fatigue Resistance of Warm Sprayed WC-CoCr Coatings by Micro-Finishing
Improving the Fatigue Resistance of Warm Sprayed WC-CoCr Coatings by Micro-Finishing
Monday, May 11, 2015: 9:40 AM
Room 104A (Long Beach Convention and Entertainment Center)
Automotive, aerospace, and energy applications demand for reliable coatings to enhance the operating efficiency and the lifetime of processes, machines, and components.
Especially for wear resistant applications, HVOF sprayed WC-CoCr coatings are commonly used. WC-CoCr coatings show perfect preconditions for highly stressed tribological systems
due to their high hardness and adapted corrosion resistance. However, dynamic loads caused by vibrations, alternating temperatures or cycling are challenging issues.
Fatigue cracking and delamination can occur, resulting in fatal damage of the coated component. Therefore, crack and fatigue resistant coatings are needed.
In this research work the influence of the substrate pre- and posttreatment (grit-blasting and micro-finishing) on the fatigue behavior of warm sprayed WC-CoCr is investigated.
It was determined that the fatigue behavior of the applied coating can be improved by micro-finishing. The smooth surface structure results in a low interface roughness.
This significantly reduces notching effects under load and enhances the fatigue strength.
Especially for wear resistant applications, HVOF sprayed WC-CoCr coatings are commonly used. WC-CoCr coatings show perfect preconditions for highly stressed tribological systems
due to their high hardness and adapted corrosion resistance. However, dynamic loads caused by vibrations, alternating temperatures or cycling are challenging issues.
Fatigue cracking and delamination can occur, resulting in fatal damage of the coated component. Therefore, crack and fatigue resistant coatings are needed.
In this research work the influence of the substrate pre- and posttreatment (grit-blasting and micro-finishing) on the fatigue behavior of warm sprayed WC-CoCr is investigated.
It was determined that the fatigue behavior of the applied coating can be improved by micro-finishing. The smooth surface structure results in a low interface roughness.
This significantly reduces notching effects under load and enhances the fatigue strength.