Ni-B/TiN composite coatings with different current densities (1.5, 3.0, 4.5, and 6.0 A/dm²) have been successfully produced on a mild steel substrate using the pulsed electrodeposition (PED) method. The effect of current density on structure, morphology, hardness, tribological, and corrosion behaviors were investigated. It was found that the composite coating produced with a current density of 4.5 A/dm² exhibited, smooth surface a uniform fine compact and crack-free structure and the particles were distributed homogeneously in the metallic matrix. After the Ni-B/TiN composite coatings deposited on the substrate, samples were heat treated at 400 C for 1 h for providing precipitation of intermetallics to improve mechanical and tribological properties. In the electrochemical measurements performed in 3.5% NaCl solution by weight, the anti-corrosion ability of the composite coating was analyzed. According to the results obtained that current density is an important parameter affecting not only the deposition mechanism of Ni-B/TiN composite depositions but also microstructural, mechanical, tribological, and corrosion properties in the PED process. Accordingly, TiN particle reinforced Ni-B composite coatings deposited by the PED method are expected to be applied as a protective coating in industrial applications with excellent hardness, superior wear resistance and anticorrosion capability.

Background: Ideal suture technique and type in tendon repair are remain unclear. This biomechanical study aimed to assess the biomechanical characteristics of three techniques, modified Kessler (mKE), modified Krackow (mKR), and modified tension Bunnell (mtBU), in sheep Achilles’ tendon tear repair using three suture types, polypropylene, polyester, and ultra-high molecular weight polyethylene (UHMWPE) sutures, which are also compared. Methods: Sixty-three Achilles’ tendons harvested from sheep were transversely hacked as a replacement for rupture in a standardized measure and repaired using mKE, mKR, and mtBU techniques with No. 2 polypropylene, polyester, and UHMWPE sutures. Biomechanical parameters, such as Young’s modulus, ultimate strength, and strength to the 5-mm gap were recorded for statistical analysis. Results: The mtBU technique with UHMWPE use resulted in increased ultimate strength, strenght to 5-mm gap, Young’s modulus, and quantity of specimens with low clinical failure modes compared to other techniques with other suture materials. Furthermore, mtBU has the lowest thickness at the repair side of the tendons. This approach showed tendon failure during maximal traction testing, whereas the mKE and mKR had polyethylene and polyester suture failures. Conclusions: The UHMWPE suture was significantly superior to the other sutures in each suture techniques in terms of strength and durability. The mtBU technique using UHMWPE suture showed better biomechanical results, implying that this repair might be more appropriate to obtain early mobilization after tendon ruptures.