Calculation Of The Uniaxial Stress Deformation And Point Defects In Bcc Nb-mo Alloy

Integrity crystal under the function of stress, its structure stability not only is flexibility theories demand consideration of importance one of the problems but also one of the problem that the structure of the research crystal correspond and the theories strength have to consider. Break a layer, crystal boundary through the research detection of opposite glide, be wrong sport, the tiny crack expand and other some micro structural characteristic of change all would to a large extent change material strength. Because of the carry of dissimilarity lotus mode, the forms of crystal become also dissimilarity.Atom of migration and point defects are close related, in proliferation of the material is much more important. Pure metals of point defects main have mono-vacancy, anti-site defect and interstitial atom. Because mono-vacancy thermodynamics stability of crystal blemish and, more easy than cleft atom move, so, mono-vacancy is mainly of the migration mechanisms. From more difficult formation of the cleft atom, under the situation that the Fu shine on etc. can also a great deal of existence, cleft atom of move and formation is also the proliferation one of the mechanisms. On the other hand it have to the function of special materials, such as pit material and aviation material...etc. bigger influence.21 aspect, the usage MAEAM model can also more convenience of research from cleft atom with empty the basic characteristic of;Study possibility the tiny view of the occurrence move mechanism. Give material proliferation provide a basic data.With BCC Nb-Mo alloy for a research object, study dissimilarity of carry lotus mode, the form of crystal become also dissimilarity, and possibility the tiny view of the occurrence migration mechanism1. On the tetragonal Bain path (a2≡a3), investigating the lattice under uniaxial loading and other physical properties. According to the calculation, analysis the circumstance of the form change, there are three point where its stress is zero:the compressive stressσ11 increases rapidly from zero at a1=0.32229nm for initial BCC structure, the internal energy E=-14.69343eV from the minimum value, where a1=a2=a3=0.32229nm. The normal stressσ11 passing through zero and becoming negative at a1=0.40329 nm, correspondingly the a2-a3=0.28819nm, the relation a1=(?) is satisfied a FCC structure. E=-14.45612e V, local maximum of the internal energy. When a1= 0.46229nm, a2=a3=0.26639 nm, stressσ11= 0, local minimum of the internal energy E=-14.56035eV, slip spontaneously into a metastable BCT structure(mBCT). 2. Calculated formation energy and lattice constant of-2.8861eV and 0.32029nm. The calculated formation energies of mono-vacancy Ef1v, anti-site defect Efant, and interstitial atom Ef1. In seven migration mechanisms of the Nb or Mo mono-vacancy, (a) 1NNJ, (b) 1NNNJ, (c) S[100]6NNCJ, (d) B[100]6NNCJ, (e) 1TNNJ and (f) [110]6NNCJ, and (g)interstitial atom migration mechanism of 1IAJ. Furthermore, they are favorable while in order of S[100]6NNCJ, B[100]6NNCJ and [110]6NNCJ for Nb vacancy, in order of B[100]6NNCJ, S [100]6NNCJ and [110]6NNCJ for Mo vacancy.