Characterization of Interfaces in Dental Alloys by HREM

本研究项目的最终目的是通过基于界面表征方法的合金晶体微观结构特征的科学设计原理来定制新的牙科合金。%的Au和50 at.用电阻率、X射线衍射、常规透射电镜和高分辨电镜结合选区电子衍射技术研究了Cu ~（2+）与Ag ~（2+）的反应。在AuCu合金中添加Ag降低了AuCu-Ag赝二元系中AuCu Ⅱ和AuCu Ⅰ在Ag-Cu双结点线外的组成区的有序化临界温度。f的无序固溶体。C. C.当它们与另一种取向变体的微孪晶片晶接触时，在微孪晶片晶的尖端附近发现了由相律预测的α_0相。 ...更多信息 AuCu-1.5at. %的Ag和AuCu-3at. %银合金。虽然在AuCu-3at. %Ag合金，在AuCu-1.5at中，在与另一种超薄片晶变体接触的超薄片晶尖端的邻近区域从未观察到这种沉淀。%Ag合金。分析了时效形成的形核的结构构型，并从HREM象中描绘出由AuCu Ⅱ和α_0相组成的复合形核。α_0 + AuCu Ⅱ与AuCu Ⅱ的分界线也随Ag含量的增加而向下倾斜至副标准K线。在Au-50 at. %Cu化学计量成分合金，在630 K附近出现失稳有序，这是由无序固溶体直接时效和淬火后回火时效的热处理方式不同所暗示的。在630 K以上的温度下，有序化是由成核和生长机制引起的，而有序化是由失稳有序机制引起的。少

The eventual purpose of the present research project is the tailoring of new dental alloys by scientific designing principle which is governed by microstructural features of the alloy crystals based on an interfacial characterization approach.Identification of phases formed by phase transformation in a series of alloys from 50at. %Au and 50at. %Cu to Ag was studied by means of electrical resistivity, X-ray diffraction, conventional transmission electron microscopy and high resolution electron microscopy combined with selected area electron diffraction technique. Addition of Ag to AuCu alloy reduced the critical temperatures of ordering of AuCu II and AuCu I at the composition region outside of the Ag-Cu binodal line in AuCu-Ag pseudobinary system. A disordered solid solution of f. c. c. alpha_0 phase which was predicted from the phase rule was found adjacent to a tip of microtwin- platelets when they were in contact with another orientation variants of the microtwin platelets as an ine … More vitable consequence of strain accommodation in AuCu-1.5at. %Ag and AuCu-3at. %Ag alloys. Although an adjacent region of a tip of microthin platelet by arcuation in AuCu-3at. %Ag alloy, such arcuation was never observed at the adjacent region of microthin platelet tip contacted with another variants of microthin platelets in AuCu-1.5at. %Ag alloy. A structural configuration of nucleous formed by ageing was analysed and depicted as a composite nucleous consisted of AuCu II and alpha_0 phases from HREM images. The boundary between alpha_0 + AuCu II and AuCu II also sloped downward for Ag content to the binormal K line. In Au-50at. %Cu stoichiometric composition alloy, the occurrence of spinodal ordering at around 630K was implied from difference in heat treatment mode between a direct ageing from disordered solid solution and tempered ageing after quenching. Ordering wasinduced by nucleation and growth mechanism at a temperature above 630K, while the ordering was originated homogeneously from the mechanism of spinodal ordering. Less