Strain-Induced Skin Elasticity and Strength

Incorporating the nanoindentation measurement of the hardness (stress) for TiCrN [24] and Si [19] surfaces yield the relationships 

This relation derives the ni values and the extent of bond contraction using Eq. (24.6). For the TiCrN surface, the Ci value is estimated to be 0.9 and the associated m — A. The Ci for Si is estimated at 0.84 with the given m — 4.88. Similarly, for amorphous carbon films [23], the Ci is around 0.8 0.2 with the given m — 2.56. Predictions also agree with the theoretically calculated thickness dependence of Young s modulus for Ni, Cu, and Ag thin films at T [74,75]. 

Incorporating the maximum Y values and the lattice contraction [29] to the BOLS expression with m = 1) leads to a C, value of 0.95 for 

The T-suppression of an organic specimen indicates the importance of the (Tin — 7) contribution to the mechanical strength. The Y value drops for polymers with size, according to the empirical relation Y — 0.014 x ln(j ) 4- 0.903 0.045 [32], with X being the particle size in nm. The T-suppression of polymers results from the low T] ( 450 K) of the specimen. The ambient testing temperature is only 2/3 of the T.  

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