In this study, a new two-step plasma immersion ion implantation technique was developed and applied for the modification of Ti6Al4V alloy; firstly ion implanting with nitrogen at high temperature and followed with oxygen in high dose. A graded titanium oxide-titanium nitride film wasobtained on the surface of the Ti6Al4V alloy. The contact angle and the microhardness of the modified alloys were measured. The friction andwear properties of UHMWPE rubbing against the modified alloys under lubrication of distilled water were investigated using a pin-on-disctribometer. The wettability and the microhardness of the alloy surfaces were found to be increased significantly after ion implantation. The frictioncoefficient decreased by nearly 5 times and the wear resistance of UHMWPE increased by about 40 times against the ion implanted Ti6Al4V alloy.Many deep furrows were found on the surface of the un-implanted alloy and were absent in the ion implanted surfaces of the alloy.

Nano-TiO2/UHMWPE composites were preparedby hot press procedure, and then radiated by gammaray in dose of 120 kGy, 250 kGy and 500 kGy. Thehardness of the composites was initially determined. Subsequentlythe wear against a CoCrMo alloy counterfacewere tested in a knee simulator under physiological salinelubrication. The morphologies of the worn surfaces wereexamined with optical microscope. The structure of thesamples was determined by IR and XRD. The resultsshowed that the wear rate of the composite UHMWPEdecreased when filled with proper amount of nano-TiO2and with the radiation dose.

Laser surface texturing technology has some advantages in reducing friction and wear ofmechanical parts in industry. In this paper, a Nd:YAG laser was used to generate microporeson T8 steel surface and the structure and morphology features of surface micropores wereobserved. Tribological experimentswere conducted with a ring-on-disc tester under variousloads and speeds. It is shown that the maximum PV value of face seal can be increased byhydrodynamic effect of micropores.

Nanohydroxyapatite reinforced poly(vinylalcohol) gel (nano-HA/PVA gel) composites has beenproposed as an articular cartilage repair biomaterial. In thispaper, nano-HA/PVA gel composites were prepared byin situ synthesis nano-HA particles in PVA solution andaccompanied with freeze/thaw method. The influence ofnano-HA content, PVA concentration, test frequency andfreeze/thaw cycle times on the viscoelastic behavior ofnano-HA/PVA gel composites were evaluated usingdynamic mechanical thermal analysis (DMTA). The resultsshowed that both storage modulus and loss modulus firstlyincreased and then presented decreasing trend with the riseof nano-HA content. Their maximum values were obtainedwhile nano-HA content was 6%. Furthermore, the G0 andG@ of the composites improve with the increase of PVAconcentrations and freeze/thaw cycle times. This effect wasmore distinct at low freeze/thaw cycles. The phase angle(tan d) of the pure PVA gel is larger than that of the nano-HA/PVA composites at the test frequency spectra, but allthe phase angle values of the tested composites were closeto that of nature bone.

The MoS2 powders were coated with Al2O3 (5 wt.%) through controlling hydrolysis of Al (NO3)3•9H2O. MoS2 powder coated with Al2O3 waswritten as MoS2/Al2O3 hereinafter. MoS2/Al2O3 powders were put into Ni plating electrolyte bath. Cetyltrimethylammonium bromide (CTAB)—the surfactant was also put into the bath. The experiment proves that MoS2/Al2O3 particles were absorbed onto the Ni plate. The amount of MoS2/Al2O3 deposited on Ni plate rises with the increasing concentration of MoS2/Al2O3 in the bath. The microhardness, micro-surface, phase and thetribological property of the MoS2/Al2O3 multi-plating coating were measured and analyzed. The performances of microhardness and wearresistance of the Ni-MoS2/Al2O3 composite are better than those of Ni-MoS2 composite.