Alumina-toughened zirconia (ATZ) composites are currently used as biomaterials in artificial hip joints. ATZ exhibits excellent mechanical properties and is resistant to degradation at low temperatures. However, it does not bond to biological bone after implantation because of its low bioactivity. In this study, the surface topology of ATZ was controlled to promote cell adhesion and proliferation, and the effect of the surface morphology on the mechanical properties was investigated. Micropatterning accelerated the progress of bone formation but reduced the strength to less than half the original strength. Specimens with a groove width of 0.1 mm, which is close to the cellular scale, showed the highest rate of bone formation under the employed conditions.

Joining carbon-fiber-reinforced plastics (CFRPs) and metals is a critical technology in the aerospace industry. Therefore, a strong and reliable composite-metal adhesive bonding technology is necessary for future aerospace applications. This study focuses on the Ply Curving Termination (PCT) method, which locally modifies the fiber orientation of CFRPs. By reducing stiffness and aligning the thermal expansion coefficient at the CFRP edges to that of the metal, the PCT method effectively decreases stress concentrations in the adhesive layer. Cooling and tensile tests were conducted to demonstrate that PCT can prevent disbonding in CFRP-Al joints under cryogenic environments and suppress overall failure of the bonded region under tensile loading. Finite element analysis was used to evaluate stress distributions under cooling and tensile conditions, revealing that the effectiveness of PCT depends on the specific thermo-mechanical conditions applied to the composite-metal joint. In the most effective case, PCT increased the disbond strength of CFRP-Al joints by 74%. These findings highlight the potential of PCT to enhance the structural reliability of CFRP-metal joints, offering a promising solution for future aerospace applications.

The sheet-winding method was selected to fabricate a cylinder used in hydrogen tanks, which has a multi-load path structure, for fuel cell vehicles. During the sheet-winding process, fiber discontinuities occurred at the hoop-winding end, and the axial layers were laminated to strengthen this area. The effect of axial layer thickness on burst strength was investigated. The two axial layers laminated using the proposed configuration exhibited a higher strength than those resulting from the filament-winding method.