Hydrogen ion irradiation led to a small decrease of impact toughness for the W-film-deposited stainless steel.
The edge-on packing oriented film was more susceptible to oxidation than the face-on oriented packing film due to higher local stresses and reaction accumulations that resulted in higher decrease of local toughness and extensive film cracking in the amorphous phase.
But Dent [20] and Yang [21], et al. also revealed the decrease of fracture toughness of WC based coatings with decreasing the WC size because of decarburization of nano WC followed by the formation of unwanted carbides, such as W2C, complex Co-W C, and metalliCo-W Csten, which candalso lower the metallical propertungstennanostructure whichsed cantings.
Also, it should be remembered that the enlarged amount of cubic phase in both types of composites may be a cause of slightly decreasing of fracture toughness value of samples, because the cubic phase has a lower indentation fracture toughness value in comparison with tetragonal phase.
So it appears that the material removal rate increases with decreasing of fracture toughness, but not exactly inversely proportional to it, as proposed by Buijs and Houten.
However, the rate of increase of Young's modulus and stress at 3% strain with mass fraction is greater than the rate of decrease of ductility and toughness.
It was also shown that the decrease of the fracture toughness with increasing humidity is less significant than the concomitant decrease in the measured value of the subcritical stress intensity factor.
The microscopic results exhibited that under quasi-static loading, disappearance of multiple crazes in the crack-tip region results in the decrease of the fracture toughness with crystallinity.
For the cool-down transient, the decrease of the fracture toughness with temperature and time plays a main role in RPV failure at the end of the cool-down process.
A significant decrease of the gel toughness and the disappearance of the hierarchical microstructure were observed in the DN gel prepared by SG and the modified SBP which was subjected to an acidic protease treatment to remove the protein components in SBP.
