Improved wear resistance of ultra-high molecular weight polyethylene by plasma immersion ion implantation

Surface modification of ultra-high molecular weight polyethylene (UHMWPE) h as been explored using the novel non-line-of-slight plasma immersion ion im plantation (PIII) with nitrogen. The modified surfaces were characterised b y SEM and a Nano Test 600 testing machine. The tribological behaviour of PH I treated UHMWPE sliding against AISI 316L stainless steel counterfaces was evaluated using a pin-on-disc tribometer under water lubricated conditions . The experimental results show that PHI is a very promising surface engine ering technique to improve such surface mechanical properties as surface ha rdness and elastic modulus of UHMWPE. As a result, the wear resistance of U HMWPE was significantly enhanced by a factor of three following PIII treatm ent, as compared with untreated material. It was found that the significant ly improved wear resistance of PHI treated UHMWPE can be mainly attributed to ion bombardment induced cross-linking, and thus surface hardening. (C) 2 001 Elsevier Science B.V. All rights reserved.