ISSN:
1573-9228
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Conclusions Existing concepts on the crystallography of MT enable one to elucidate the general lines of the martensite deformation, which is confirmed by the present comparison of these concepts with the results of special experiments on RMD. At the same time, the comparison leads us to formulate some particular problems (the following is not a complete list): 1) establishment of the mechanism of accumulation and elimination of RMD at each stage and research on the change between stages; 2) elucidation of the effects of external stress on the crystallographic parameters of MT: the lattice parameters of the phases, the habit plane, and the magnitude and system of the secondary deformation; 3) identification of the elementary processes responsible for the inelastic phenomena at stresses below the macroscopic martensite-deformation limit, and the nature of this limit; 4) elucidation of the mechanism for the suppression of RMD by plastic strain during loading of the martensite phase; 5) research on the secondary deformation in reverse MT in a gripped or loaded specimen; 6) examination of RMD as a function of the complete set of parameters that determine the texture of the martensite phase. To this list we can add problems of applied character such as: 7) the search for ways of realizing the complete scope for RMD in the practical use of FME, where usually it is necessary to eliminate incomplete shape recovery; and 8) the search for ways of improving the stability of RMD characteristics in the presence of external factors that produce internal fields. Outside the framework of the present exposition, there is a general problem related to the dependence of the RMD characteristics on the crystallography of the MT product, the chemical composition of the material, the kinetic characteristics of the MT process, various slow secondary diffusion and relaxation processes, etc. For brevity, we have discussed the results of experiments on an alloy of one particular composition. Naturally, these results do not reflect all aspects of the problem that can occur for alloys of other compositions or other systems. The accumulation and the elucidation of macroscopic experimental information (this treatment is mainly restricted to such) does not rule out research on local microscopic situations by direct methods, but in fact requires this. Here we may mention the detailed study of dislocation structures and elastic fields produced during MT and martensite deformation. Another problem concerns research on the local situations in the interaction of martensite boundaries with crystallographic defects (the theoretical basis for this is provided by [57]). Solution to these problems require improvements in existing experimental methods.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00898750
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