Orientation relationship of eutectoid FeAl and FeAl2
نویسندگان
چکیده
Fe-Al alloys in the aluminium range of 55-65 at.% exhibit a lamellar microstructure of B2-ordered FeAl and triclinic FeAl2, which is caused by a eutectoid decomposition of the high-temperature Fe5Al8 phase, the so-called ∊ phase. The orientation relationship of FeAl and FeAl2 has previously been studied by Bastin et al. [J. Cryst. Growth (1978 ▸), 43, 745] and Hirata et al. [Philos. Mag. Lett. (2008 ▸), 88, 491]. Since both results are based on different crystallographic data regarding FeAl2, the data are re-evaluated with respect to a recent re-determination of the FeAl2 phase provided by Chumak et al. [Acta Cryst. (2010 ▸), C66, i87]. It is found that both orientation relationships match subsequent to a rotation operation of 180° about a 〈112〉 crystallographic axis of FeAl or by applying the inversion symmetry of the FeAl2 crystal structure as suggested by the Chumak data set. Experimental evidence for the validity of the previously determined orientation relationships was found in as-cast fully lamellar material (random texture) as well as directionally solidified material (∼〈110〉FeAl || solidification direction) by means of orientation imaging microscopy and global texture measurements. In addition, a preferential interface between FeAl and FeAl2 was identified by means of trace analyses using cross sectioning with a focused ion beam. On the basis of these habit planes the orientation relationship between the two phases can be described by ([Formula: see text]01)FeAl || (114)[Formula: see text] and [111]FeAl || [1[Formula: see text]0][Formula: see text]. There is no evidence for twinning within FeAl lamellae or alternating orientations of FeAl lamellae. Based on the determined orientation and interface data, an atomistic model of the structure relationship of Fe5Al8, FeAl and FeAl2 in the vicinity of the eutectoid decomposition is derived. This model is analysed with respect to the strain which has to be accommodated at the interface of FeAl and FeAl2.
منابع مشابه
Effects of Tungsten on the Pearlite Reaction in a Eutectoid Steel
The effect of an addition of 0.37 Wt % Won the overall transformation rate of the austenitepearlite reaction in a eutectoid steel is examined. Pearlite growth rates and interlamerllar spacing are measured as a function of transformation temperatures. Tungesten raises the Ael temperature, for most transformation temperatures, decreases the overall reaction rate, the growth rate and the interlame...
متن کاملرفتار سایشی کامپوزیتهای WC-Co و WC-FeAl-B در دمای محیط و 300 درجه سانتیگراد
In this research, the wear behavior of commercial grades of WC-10wt%Co (H10F), WC-40vol%Co and WC-40vol%FeAl-B composites with different amounts of boron from zero to 1000 ppm has been investigated by the pin on disk test method at high temperature. The wear tests were done under load of 40 N, a distance of 100 m and at ambient temperature, 200 ̊C and 300 ̊C. Wear surfaces were examine...
متن کاملThin Film Media II M. Russak, Chairman FeAl underlayers for CoCrPt thin film longitudinal media
B2 ordered FeAl films with a small, uniform grain size have been produced by rf diode sputter deposition on glass substrates. CoCrPt films grown on FeAl underlayers were found to have the ~101̄0! lamellar texture. The in-plane coercivities (Hc) of the CoCrPt/FeAl films are comparable to those of the CoCrPt/Cr films and they can be further improved by inserting a thin Cr intermediate layer betwee...
متن کاملInvestigation of phononic and thermal properties of the compound FeAl and Fe3Al using pseudopotentials method (Research Article)
Iron aluminide intermetallic compound, including compounds that have great features is that it's so great properties, due to its increasing use in industry is different. In thiswork, structural and dynamic properties of FeAl compounds including the structure of energybands, density of states, phonon and thermal properties in two-phase structures regularly evaluated and calculated. Calculations ...
متن کاملThe Relationship between Goal Orientation (Learning, Performance Approach and Performance Avoidance) and Audit Judgment with the Mediator Role of Self-efficacy
The purpose of this study was to investigate the relationship between goal orientation (Learning, Performance approach and Performance avoidance) and audit judgment with the mediator role of self-efficacy. The goal orientation is a personality trait that can be effective in performing tasks. The study is a pre-survey type-applied study. Also, a questionnaire was used to survey the subjects and ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 49 شماره
صفحات -
تاریخ انتشار 2016