Papers by Keyword: Homogenization

Abstract: The objective of the present study was to melt and cast AA2195 alloy in Vacuum Induction Melting (VIM) under dynamic inert atmosphere. These billets were homogenized and subsequently hot forged and rolled to sheets. The products in the form of sheets were subjected to T8 (Solution Treatment +WQ+CW+Aging) temper condition. Mechanical properties were evaluated at room temperature and correlated with microstructure. Highest mechanical properties obtained in T87 temper have been reported.

Abstract: A novel technique of pure Lithium addition has been adopted for the processing of Al-Cu-Li alloy AA2195 cast ingots (7-8 kg each) in VIM under dynamic inert atmosphere, which gives more than 95% recovery of Lithium. The cast billets were homogenized, forged and converted into 12mm diameter rods by caliber rolling in the temperature range of 250°C, 300°C, 350°C and 400°C. The caliber rolled rods were treated to T8 (Solution Treatment+WQ+CW+Aging) condition. Mechanical properties were evaluated for T8 tempered bars at room temperature and correlated with microstructural observations. Highest mechanical properties in T87 temper have been obtained for rods caliber rolled at 350°C temperature.

Abstract: The expressions of the effective elastic constants of composite material with cylindrical inclusions are derived based on M-T method, and it can be used in discussing the approximate range of effective elastic constant of air. Moreover, it is possible to homogenize tube-sheet by making use of the expression. The numerical result obtained is in good agreement with effective elastic constant adopted by the ASME code. It demonstrates that the approach is effective and accurate. At the last, the relationship between effective elastic and thickness of the tube-sheet is discussed.

Abstract: The cosine solution of the Fick-2 Law, which was considered as the mathematical model of homogenization of dendritic segregation, has always been used to analyze high temperature diffusion. Cosine solution can not exactly describe the actual distribution of alloying elements in dendrite, as the slope of cosine curve is quite gentle. Based on segregation ratio SR, a new mathematical model was established by using Gauss solution of the Fick-2 Law. The new model could describe the evolution of homogenization of alloying elements during the process of high temperature, which was proved by some specific examples.

Abstract: In commercial 8xxx alloys several material characteristics such as softening behaviour, strength and technological ductility are influenced by alloying elements in their solute and precipitated form (i.e. microchemistry). Depending on the thermo-mechanical processing conditions a spectrum of microchemistry states (including variations of solute level, phase volume fraction, phase morphology) and therefore a spectrum of possible microchemistry-microstructure interactions can be obtained and used for a set up of sheet properties. In the present paper, the impact of homogenization conditions on the microchemistry development in selected 8xxx alloys is discussed with a view of controlling final properties. Effect of the processing route on the microchemistry evolution is demonstrated using the statistical Classical Nucleation and Growth (ClaNG) model.

Abstract: FSP is an allied technology of friction stir welding (FSW). These processes are reviewed and the additional considerations such as processing pattern and step over distance in FSP are introduced. The application of FSP to cast metals including AA5083, Al-7Si and NiAl bronze is summarized. As-cast microstructures may be converted to a wrought condition in the absence of external shape change and the extent of grain refinement and homogenization of microstructure is documented. The FSP-induced superplastic response of AA5083, enhanced ductility of Al-7Si and surface hardening of NiAl bronze are summarized as examples of properties developed by FSP.

Abstract: The purpose of this paper is to evaluate the effective mechanical properties of composite ceramic with randomly distributed multi-phase inclusions. The RVE finite element subcell technique based on numerical homogenization theory is used to separate the multi-phase composite into the layered unit cell models which are generated by a modified random sequential adsorption algorithm (RSA). The numerical results are also compared and verified with experiment data.

Abstract: Abstract. Based on the newly developed homogenization theory of masonry, homogenization model of masonry is built in this paper. And a failure criteria adapation to masonry homogenization units is suggested union finite element analysis result of homogenization model.

Abstract: By means of two-scale method, the approximation solution of the displacement for structure of composites with small periodic perforated configuration is built, and the algorithm corresponding to two-scale finite element method is presented. One new method of higher order for computing approximate solution of the displacement in periodic perforated composites is given.

Abstract: The influence of the bond pattern on the in-plane limit strength of masonry is analyzed through a simplified procedure based on the application of the safe theorem of limit analysis to the unit cell that generates the whole masonry by periodic repetition. The limit strength domains of running bond, English bond and herringbone bond masonry are obtained with different orientations of the mortar bed joints with respect to the principal directions of the average stress. The effects of different brick geometries are analyzed and comparisons between strength properties of different masonry patterns are made.