Strengthening rates

An effect that can lower the strengthening rate by the ion exchange process is the stress relaxahon that can occur during this process, leading to a reduction in the magnitude of... 

Solid-solution strengthening rate. Solute element ... 

In paper [27] it has also been shown that PCP samples strengthening with tension in the plastic deformation process occurs faster the larger degree of tension at which the sample was crystallised. The strengthening rate of samples on this part of the stress-strain (a-e) curve starts increasing sharply at X = X [27]. 

A hardness indentation causes both elastic and plastic deformations which activate certain strengthening mechanisms in metals. Dislocations created by the deformation result in strain hardening of metals. Thus the indentation hardness test, which is a measure of resistance to deformation, is affected by the rate of strain hardening. 

The rate of saponification of ethyl 2-thenoate, in contrast to ethyl 3-thenoate, was found to be considerably slower than predicted from the pKa of the acid, showing that the reactivities of thiophenes do not parallel those of benzene. The first explanation, that this was produced by a steric effect of the ring sulfur similar to the case in or /lo-substituted benzenes and in ethyl 1-naphthoate, could not be upheld when the same effect was found in ethyl 2-furoate. It was later ascribed to a stereospecific acid strengthening factor, involving the proper relation of the carboxylic hydrogen and the heteroatom, as the rate of saponification of 2-thienylacrylic acid was in agreement with that predicted from the acid constants. ... 

The pronounced rate enhancement with positive AUWR and A is thus due to the weakening of the Pd=0 bond according to rule LI while the observed rate enhancement with negative AUWr and is due to enhanced binding of CHX on the catalyst surface due to the strengthening of the Pd=0 bond. 

---