PtRh Alloy Lattice Inversion Department Of Construction And Application Potential

The ZrO2dispersion strengthened PtRh alloys is the most widely used composite material in high temperatures because of its oxidative resistance, high strength under high temperature, resistance to creep and excellent machining properties.This paper firstly construct the interatomic potentials of some the most widely used PtRh alloys including PtRhl,3,5,6,7,10,13,20,30,40,50,60,70,90as well as the pure metals Pt and Rh. The First Princple of Density Functional Methods are used to calculate the nearest distance between atoms and the cohesive energys of the unit cells. Then based on the data getting form the FP calculation, the CHEN-Mobius lattice inversion method was used to fit the first priceple calculation results to get the real pair potentials of the16materials. And the potentials are tested to be reliable.Based on the constructed potenials go on Molecular Dynamic Simulation research of the atom interactions on ZrO2/PtRh interfaces using the16materials as matrix alloys respectively. The research mainly aims at how the different contents of oxide, the different distributions of O and Zr atoms, the different temperatures and the different vacancy concentrations will effect the interactions on the interfaces.The simulation results show that when the oxide content is too high, the interactions between atoms on the interfaces will be quite strong, so will be the bonding between atoms, therefore, the diffuse of O and Zr atoms will become weakend, so the deapth of the oxide atoms can enter will be very shallow. When there is not enough diffusion, the dispersion will be influenced, as a result of the strenghth of the materials will be reduced. This phenomenon shows that in practial, not the more oxide the better strength will be. Through the test of different configurations of O and Zr atom on the interfaces, we can see that atom Zr will block the diffusion of atom O, so when the O atoms are surrounded by Zr atoms, it will be difficult for them to get out and enter the basic PtRh alloys, therefore the PtRh alloys will not be fully oxided. And the high temperature will be good for the diffusion of the O, Zr atoms and give system a higher energy at the same time. So the interactions between atoms will be stronger as a result of more strenghth the materials will be. The vacancy will do no good for the diffusion of the atom O and Zr, so in practical it should be controled.Finally, the interface model of PtRh (111) with a edege dislocation and monocline ZrO2(100) was builded, and using the Molecular Dynamic Simulation to observe the interactions between the oxide particles and the edege dislocations, therefore to find out how they really work on the microstructure system.The simulation result show that atom Zr can not spread on the close packing lattice plane of fcc PtRh (111) whether there has a edege dislocation or not, and edege dislocation will do no diffrance to the diffusion ability of atom O. But the diffison of atom O is better on specific direction.At last, PtRhl atom will reunite in all simulation processes. And when the temperature is getting higher, the reunite atoms tend to separate. This phenomenon shows that the interactions between PtRhl atoms are much stronger than they are to oxide atoms. This phenomenon is first observed, and need more reaserch to explain it.