Tribological Behavior of Diamond-Like Carbon (DLC) Coatings on Metals for Total Knee Arthroplasty Under Boundary Friction Conditions

Rothammer B, Weikert T, Tremmel S (2019)

Publication Language: English

Publication Type: Conference contribution, Conference Contribution

Publication year: 2019

Event location: Sendai JP

URI: https://www.archiv.mfk.tf.fau.de?file=pubmfk_5db1452b6e947

Abstract

The knee joint is one of the most stressed joints in the human body. The failure of a natural knee joint is 96 % due to gonarthrosis, which requires the implantation of an artificial joint. However, a primary artificial knee joint has an average lifetime of about 15 years. Wear is the most common reason for load-bearing implant failure, as this leads to an aseptic loosening of the knee arthroplasty. In implant research, efforts are being made to reduce polymeric inlay wear by the application of tribologically effective Diamond-like Carbon (DLC) coatings. Therefore, this study focuses on the deposition of wear-reducing coating systems with high adhesion to the medical substrates Ti6Al4V (3.7165; 39 ± 2 HRC) and CoNi35Cr20Mo10 (2.4999; 47 ± 1 HRC). For this reason, pure (a‑C:H), silicon oxide-modified (a‑C:H:SiO) and titanium-containing (a‑C:H:Ti) hydrogen-containing amorphous carbon coatings are investigated with regard to the forms of wear. Subsequently, wear mechanisms have to be identified in order to derive wear-reducing coating systems. The tribological effectiveness of the carbon coating systems can be promoted in particular by a high adhesion to the base material, so that further attention is paid to the mechanical investigation of the adhesion. The uncoated and coated samples were tested against medical PE‑UHMW (1401; HB = 33 N/mm2) in a ring-on-disc test with minimal lubrication of fetal bovine serum (FBS). Various wear mechanisms were observed during the sliding process, which in turn affect the coefficient of friction. The obvious traces of wear on PE‑UHMW indicate abrasive and adhesive wear. The wear particles are usually fibrous or particulate and have a size of at least 33.8 µm. This value is above the critical value of 0.1 µm, below which increased macrocytic reactions are triggered even with small abrasion volume, and thus promote the risk of osteolysis and also of aseptic loosening. A reason for the discrepancy in particle size arises from the different in‑vitro test setups (tribometer, knee simulator) and the in‑vivo used joint replacement. In general, the wear volume should be kept low for particles in the order of 0.2...0.6 µm.

Authors with CRIS profile

Benedict Rothammer Chair of Engineering Design Tim Weikert Chair of Engineering Design Stephan Tremmel Chair of Engineering Design

How to cite

APA:

Rothammer, B., Weikert, T., & Tremmel, S. (2019). Tribological Behavior of Diamond-Like Carbon (DLC) Coatings on Metals for Total Knee Arthroplasty Under Boundary Friction Conditions. In Proceedings of the International Tribology Conference Sendai 2019. Sendai, JP.

MLA:

Rothammer, Benedict, Tim Weikert, and Stephan Tremmel. "Tribological Behavior of Diamond-Like Carbon (DLC) Coatings on Metals for Total Knee Arthroplasty Under Boundary Friction Conditions." Proceedings of the International Tribology Conference Sendai 2019, Sendai 2019.

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