Increasing the length and percentage of fiber-reinforcement in both water and hot dry curing, was found to improve the post-crack flexural strength and the toughness coefficients, but decreased the first crack and the compressive strengths.
In particular, Young's modulus, Poisson's ratio, critical normal and shear stresses and strains, fracture and fragmentation energies, fracture toughness and coefficient of thermal expansion are deduced.
Additionally, the presence of rare earth in laser claddings can notably enhance tribo-mechanical properties such as surface hardness, modulus of elasticity, fracture toughness, friction coefficient and wear rate.
Their inherent properties, such as capability of operating at temperatures far above metals, high level of hardness and toughness, low coefficient of thermal expansion and high thermal conductivity rendered ceramics to be one of the leading engineering materials.
Amorphous and amorphous/nanocrystal thin films covering roughly a composition range formulated by [B B5C]Mg (x = 2) ~ [B B5.5C0.5]B0.5Mg0.5 (x = 1), prepared by magnetron sputtering, show increasing hardness, elastic modulus, toughness and coefficient of friction with increasing boron contents.
However, their lower fracture toughness and lower coefficient of thermal expansion (CTE) compared to YSZ lead to premature coating failure.
Friction coefficient, adhesion, toughness and mechanical properties of the TiAlSiC coatings were characterized by nanoscratch tester and nanoindentation measurements.
The coatings were evaluated in terms of their mechanical properties, adhesion strength, intrinsic stress, fracture toughness, room-temperature friction coefficient, as well as wear resistance and fatigue strength.
Zirconia (ZrO2) stabilized with 8 wt.% Y2O3 is the most common material to be applied in thermal barrier coatings (TBC) owing to its excellent properties: low thermal conductivity; high toughness and thermal expansion coefficient similar to iron.
