Investigation on the crystallographic orientation relationships and interface atomic structures in an in-situ Ti2AlN/TiAl composite. (15th September 2017)

• Record Type: Journal Article
• Authors: Liu, Pei; Sun, Dongli; Han, Xiuli; Wang, Qing
• Is Part Of: Materials & design. Volume 130(2017)
• Page Start: 239
• Page End: 249
• Publication Date: 2017-09-15
• Subjects: Ti2AlN/TiAl composite -- Reactive hot processing -- Crystallographic orientation relationship -- Interface atomic structure; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2017.05.061
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: In this research work, 15 vol% Ti2 AlN particles reinforced TiAl alloy matrix composite was prepared by an in-situ reactive hot processing method using Ti, Al and TiN powders as raw materials. Transmission electron microscope (TEM) coupled with energy-dispersive spectroscopy (EDS) was utilized to investigate the morphology characteristics of Ti2 AlN particles. The crystallographic orientation relationships and interface atomic structures between various shaped Ti2 AlN particles and TiAl matrix were investigated by the means of selected area electron diffraction (SAED) and high resolution transmission electron microscopy (HRTEM). The results show that four kinds of Ti2 AlN particles presented in the composite, which include vast majority of elliptical and polygonal Ti2 AlN particles with the sizes of 4 μm, few hexagonal Ti2 AlN particles with the sizes of 4 μm and small plate Ti2 AlN particles with the sizes of 0.4 μm. The elliptical and polygonal Ti2 AlN particles have no fixed crystallographic orientation relationship with TiAl matrix, the elliptical and polygonal Ti2 AlN/TiAl interfaces are incoherent interphase boundaries composed by many atomic-scale microfacets. The hexagonal and small plate Ti2 AlN particles have a fixed orientation relationship with TiAl matrix. Both the hexagonal and small plate Ti2 AlN particles have a ledge and terrace coherent interface with TiAl matrix. Graphical abstract: Highlights: The interfacial orientation relationships and atomic structures between Ti2 AlN particles and TiAl matrix were studied. The elliptical and polygonal Ti2 AlN particles have no fixed crystallographic orientation relationship with TiAl matrix. The elliptical and polygonal Ti2 AlN/TiAl interfaces are incoherent boundaries composed by many atomic-scale microfacets. The hexagonal and small plate Ti2 AlN particles have a fixed crystallographic orientation relationship with TiAl matrix. The hexagonal and small plate Ti2 AlN particles have a ledge and terrace coherent interface with TiAl matrix.