TY - GEN

T1 - The Interaction of Two Amorphous Carbon Coatings (ta-C and a-C) on Polymer Substrates and the Consequences of the Tribological Contact Situation

AU - Stiller, Tanja

AU - Tervakangas, S.

AU - Manning, N.

AU - Jarry, O.

AU - Slapnik, J.

AU - Cerne, B.

AU - Grun, Florian

AU - Hausberger, Andreas

PY - 2023/9/30

Y1 - 2023/9/30

N2 - In industrial applications, metal parts are often coated to prevent wear and thus extend their servicelife. In some cases, metal parts are replaced with polymers for weight reduction and lower energyconsumption during manufacturing. One drawback is that polymers are softer than metals and hencemore susceptible to wear. A more recent approach is to coat the soft polymer with a hard, wearresistantcoating. The best-known coatings for this are diamond-like carbon coatings and their subset,amorphous carbon coatings. The coating process is challenging considering the temperature limits andthe correlation between coating thickness and bonding.In this study, a-C and ta-C coatings were deposited on polymers and tested under 3 different contactconditions, i.e. ball-on-disc, pin-on-disc, and 2-disc-test. This represents a transition from model tocomponent testing. Indentation tests were performed to understand the interaction between polymerand coating. Depending on the coating, the behaviour was either elastic or plastic, which helped tounderstand the stress distribution in the contact.Hertzian contact pressure with a steel ball causes wear on the mating part and the coating. By replacingthe mating part with a polymer, only the polymer mating part will wear. Changing the tribosystem to aflat contact showed a significant reduction in wear. One reason for this is the increased contact area,which leads to a changed stress distribution. With the change from flat to line contact and a change inmovement (from pure sliding to sliding-rolling), the shear forces between the coating and substrate aresignificantly reduced. The effect of speed, load, and slip ratio on the performance of the differentmaterial pairings was analysed. Coated polymers also allow the pairing of incompatible materials, whichwould result in unstable frictional contact. Moreover, coated polymers exhibit high wear resistance aslong as the load is applied over an area rather than a small point.

AB - In industrial applications, metal parts are often coated to prevent wear and thus extend their servicelife. In some cases, metal parts are replaced with polymers for weight reduction and lower energyconsumption during manufacturing. One drawback is that polymers are softer than metals and hencemore susceptible to wear. A more recent approach is to coat the soft polymer with a hard, wearresistantcoating. The best-known coatings for this are diamond-like carbon coatings and their subset,amorphous carbon coatings. The coating process is challenging considering the temperature limits andthe correlation between coating thickness and bonding.In this study, a-C and ta-C coatings were deposited on polymers and tested under 3 different contactconditions, i.e. ball-on-disc, pin-on-disc, and 2-disc-test. This represents a transition from model tocomponent testing. Indentation tests were performed to understand the interaction between polymerand coating. Depending on the coating, the behaviour was either elastic or plastic, which helped tounderstand the stress distribution in the contact.Hertzian contact pressure with a steel ball causes wear on the mating part and the coating. By replacingthe mating part with a polymer, only the polymer mating part will wear. Changing the tribosystem to aflat contact showed a significant reduction in wear. One reason for this is the increased contact area,which leads to a changed stress distribution. With the change from flat to line contact and a change inmovement (from pure sliding to sliding-rolling), the shear forces between the coating and substrate aresignificantly reduced. The effect of speed, load, and slip ratio on the performance of the differentmaterial pairings was analysed. Coated polymers also allow the pairing of incompatible materials, whichwould result in unstable frictional contact. Moreover, coated polymers exhibit high wear resistance aslong as the load is applied over an area rather than a small point.

M3 - Conference contribution

BT - Proceedings of 9th International Tribology Conference, ITC Fukuoka 2023

T2 - 9th International Tribology Conference, Fukuoka 2023

Y2 - 25 September 2023 through 30 October 2023

ER -